WorldWideScience

Sample records for equivalent noise levels

  1. [Equivalent continuous noise level in neonatal intensive care unit associated to burnout syndrome].

    Science.gov (United States)

    Garrido Galindo, A P; Camargo Caicedo, Y; Vélez-Pereira, A M

    2015-01-01

    Noise levels in neonatal intensive care units allow the appearance of symptoms associated with burnout such as stress, irritability, fatigue and emotional instability on health care personnel. The aim of this study was to evaluate the equivalent continuous noise levels in the neonatal intensive care unit and compare the results with noise levels associated with the occurrence of burnout syndrome on the care team. Continuous sampling was conducted for 20 days using a type I sound level meter on the unit. The maximum, the ninetieth percentile and the equivalent continuous noise level (Leq) values were recorded. Noise level is reported in the range of 51.4-77.6 decibels A (dBA) with an average of 64 dBA, 100.6 dBA maximum, and average background noise from 57.9 dBA. Noise levels exceed the standards suggested for neonatal intensive care units, are close to maximum values referred for noise exposure in the occupational standards and to noise levels associated with the onset of burnout; thus allowing to infer the probability of occurrence of high levels of noise present in the unit on the development of burnout in caregivers. Copyright © 2013 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  2. Self-reported sleep disturbances due to railway noise: exposure-response relationships for nighttime equivalent and maximum noise levels.

    Science.gov (United States)

    Aasvang, Gunn Marit; Moum, Torbjorn; Engdahl, Bo

    2008-07-01

    The objective of the present survey was to study self-reported sleep disturbances due to railway noise with respect to nighttime equivalent noise level (L(p,A,eq,night)) and maximum noise level (L(p,A,max)). A sample of 1349 people in and around Oslo in Norway exposed to railway noise was studied in a cross-sectional survey to obtain data on sleep disturbances, sleep problems due to noise, and personal characteristics including noise sensitivity. Individual noise exposure levels were determined outside of the bedroom facade, the most-exposed facade, and inside the respondents' bedrooms. The exposure-response relationships were analyzed by using logistic regression models, controlling for possible modifying factors including the number of noise events (train pass-by frequency). L(p,A,eq,night) and L(p,A,max) were significantly correlated, and the proportion of reported noise-induced sleep problems increased as both L(p,A,eq,night) and L(p,A,max) increased. Noise sensitivity, type of bedroom window, and pass-by frequency were significant factors affecting noise-induced sleep disturbances, in addition to the noise exposure level. Because about half of the study population did not use a bedroom at the most-exposed side of the house, the exposure-response curve obtained by using noise levels for the most-exposed facade underestimated noise-induced sleep disturbance for those who actually have their bedroom at the most-exposed facade.

  3. Equivalent noise level response to number of vehicles: a comparison between a high traffic flow and low traffic flow highway in Klang Valley, Malaysia

    OpenAIRE

    Halim, Herni; Abdullah, Ramdzani

    2014-01-01

    HIGHLIGHTS Highway traffic noise is a serious problem in Malaysia Heavy traffic flow highway recorded higher noise level compared to low traffic flow Noise level stabilized at certain number of vehicles on the road i.e above 500 vehicles. Although much research on road traffic noise has found that noise level increase are influenced by driver behavior and source-receiver distance, little attention has been paid to the relationship between noise level and total number of vehicles...

  4. Simulation-Based Prediction of Equivalent Continuous Noises during Construction Processes.

    Science.gov (United States)

    Zhang, Hong; Pei, Yun

    2016-08-12

    Quantitative prediction of construction noise is crucial to evaluate construction plans to help make decisions to address noise levels. Considering limitations of existing methods for measuring or predicting the construction noise and particularly the equivalent continuous noise level over a period of time, this paper presents a discrete-event simulation method for predicting the construction noise in terms of equivalent continuous level. The noise-calculating models regarding synchronization, propagation and equivalent continuous level are presented. The simulation framework for modeling the noise-affected factors and calculating the equivalent continuous noise by incorporating the noise-calculating models into simulation strategy is proposed. An application study is presented to demonstrate and justify the proposed simulation method in predicting the equivalent continuous noise during construction. The study contributes to provision of a simulation methodology to quantitatively predict the equivalent continuous noise of construction by considering the relevant uncertainties, dynamics and interactions.

  5. What Do Contrast Threshold Equivalent Noise Studies Actually Measure? Noise vs. Nonlinearity in Different Masking Paradigms.

    Directory of Open Access Journals (Sweden)

    Alex S Baldwin

    Full Text Available The internal noise present in a linear system can be quantified by the equivalent noise method. By measuring the effect that applying external noise to the system's input has on its output one can estimate the variance of this internal noise. By applying this simple "linear amplifier" model to the human visual system, one can entirely explain an observer's detection performance by a combination of the internal noise variance and their efficiency relative to an ideal observer. Studies using this method rely on two crucial factors: firstly that the external noise in their stimuli behaves like the visual system's internal noise in the dimension of interest, and secondly that the assumptions underlying their model are correct (e.g. linearity. Here we explore the effects of these two factors while applying the equivalent noise method to investigate the contrast sensitivity function (CSF. We compare the results at 0.5 and 6 c/deg from the equivalent noise method against those we would expect based on pedestal masking data collected from the same observers. We find that the loss of sensitivity with increasing spatial frequency results from changes in the saturation constant of the gain control nonlinearity, and that this only masquerades as a change in internal noise under the equivalent noise method. Part of the effect we find can be attributed to the optical transfer function of the eye. The remainder can be explained by either changes in effective input gain, divisive suppression, or a combination of the two. Given these effects the efficiency of our observers approaches the ideal level. We show the importance of considering these factors in equivalent noise studies.

  6. High level white noise generator

    International Nuclear Information System (INIS)

    Borkowski, C.J.; Blalock, T.V.

    1979-01-01

    A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application

  7. High level white noise generator

    Science.gov (United States)

    Borkowski, Casimer J.; Blalock, Theron V.

    1979-01-01

    A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application.

  8. Acceptable noise level

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Nielsen, Lars Holme; Lantz, Johannes

    2012-01-01

    The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjects...... using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli....

  9. Acceptable noise level

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Nielsen, Lars Holme; Lantz, Johannes

    2012-01-01

    The acceptable noise level (ANL) is used to quantify the amount of background noise that subjects can accept while listening to speech, and is suggested for prediction of individual hearing-aid use. The aim of this study was to assess the repeatability of the ANL measured in normal-hearing subjec...... using running Danish and non-semantic speech materials as stimuli and modulated speech-spectrum and multi-talker babble noises as competing stimuli....

  10. The equivalent internal orientation and position noise for contour integration.

    Science.gov (United States)

    Baldwin, Alex S; Fu, Minnie; Farivar, Reza; Hess, Robert F

    2017-10-12

    Contour integration is the joining-up of local responses to parts of a contour into a continuous percept. In typical studies observers detect contours formed of discrete wavelets, presented against a background of random wavelets. This measures performance for detecting contours in the limiting external noise that background provides. Our novel task measures contour integration without requiring any background noise. This allowed us to perform noise-masking experiments using orientation and position noise. From these we measure the equivalent internal noise for contour integration. We found an orientation noise of 6° and position noise of 3 arcmin. Orientation noise was 2.6x higher in contour integration compared to an orientation discrimination control task. Comparing against a position discrimination task found position noise in contours to be 2.4x lower. This suggests contour integration involves intermediate processing that enhances the quality of element position representation at the expense of element orientation. Efficiency relative to the ideal observer was lower for the contour tasks (36% in orientation noise, 21% in position noise) compared to the controls (54% and 57%).

  11. Noise in restaurants: levels and mathematical model.

    Science.gov (United States)

    To, Wai Ming; Chung, Andy

    2014-01-01

    Noise affects the dining atmosphere and is an occupational hazard to restaurant service employees worldwide. This paper examines the levels of noise in dining areas during peak hours in different types of restaurants in Hong Kong SAR, China. A mathematical model that describes the noise level in a restaurant is presented. The 1-h equivalent continuous noise level (L(eq,1-h)) was measured using a Type-1 precision integral sound level meter while the occupancy density, the floor area of the dining area, and the ceiling height of each of the surveyed restaurants were recorded. It was found that the measured noise levels using Leq,1-h ranged from 67.6 to 79.3 dBA in Chinese restaurants, from 69.1 to 79.1 dBA in fast food restaurants, and from 66.7 to 82.6 dBA in Western restaurants. Results of the analysis of variance show that there were no significant differences between means of the measured noise levels among different types of restaurants. A stepwise multiple regression analysis was employed to determine the relationships between geometrical and operational parameters and the measured noise levels. Results of the regression analysis show that the measured noise levels depended on the levels of occupancy density only. By reconciling the measured noise levels and the mathematical model, it was found that people in restaurants increased their voice levels when the occupancy density increased. Nevertheless, the maximum measured hourly noise level indicated that the noise exposure experienced by restaurant service employees was below the regulated daily noise exposure value level of 85 dBA.

  12. Noise in restaurants: Levels and mathematical model

    Directory of Open Access Journals (Sweden)

    Wai Ming To

    2014-01-01

    Full Text Available Noise affects the dining atmosphere and is an occupational hazard to restaurant service employees worldwide. This paper examines the levels of noise in dining areas during peak hours in different types of restaurants in Hong Kong SAR, China. A mathematical model that describes the noise level in a restaurant is presented. The 1-h equivalent continuous noise level (Leq,1-h was measured using a Type-1 precision integral sound level meter while the occupancy density, the floor area of the dining area, and the ceiling height of each of the surveyed restaurants were recorded. It was found that the measured noise levels using Leq,1-h ranged from 67.6 to 79.3 dBA in Chinese restaurants, from 69.1 to 79.1 dBA in fast food restaurants, and from 66.7 to 82.6 dBA in Western restaurants. Results of the analysis of variance show that there were no significant differences between means of the measured noise levels among different types of restaurants. A stepwise multiple regression analysis was employed to determine the relationships between geometrical and operational parameters and the measured noise levels. Results of the regression analysis show that the measured noise levels depended on the levels of occupancy density only. By reconciling the measured noise levels and the mathematical model, it was found that people in restaurants increased their voice levels when the occupancy density increased. Nevertheless, the maximum measured hourly noise level indicated that the noise exposure experienced by restaurant service employees was below the regulated daily noise exposure value level of 85 dBA.

  13. Period analysis at high noise level

    International Nuclear Information System (INIS)

    Kovacs, G.

    1980-01-01

    Analytical expressions are derived for the variances of some types of the periodograms due to normal-distributed noise present in the data. The equivalence of the Jurkevich and the Warner and Robinson methods is proved. The optimum phase cell number of the Warner and Robinson method is given; this number depends on the data length, signal form and noise level. The results are illustrated by numerical examples. (orig.)

  14. Background noise levels in Europe

    OpenAIRE

    Gjestland, Truls

    2008-01-01

    - This report gives a brief overview of typical background noise levels in Europe, and suggests a procedure for the prediction of background noise levels based on population density. A proposal for the production of background noise maps for Europe is included.

  15. Noise levels in Damascus city

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Maslmani, Y.

    2004-01-01

    Outdoor noise levels were measured at 22 sites in Damascus city. Sound level meter model NC-10 with a 20-140 dBA selectable range was used in the current investigation. At each site noise data were collected from 7 to 21 o'clock. The results showed that the noise levels were higher than WHO (World Health Organization) standard by 5-24.7 dB, 10-16 dB, 10-11 dB and 12-17 dB in residential, commercial, Commercial-industrial, and Heavy traffic streets respectively. Indoor and outdoor noise levels in some hospitals were higher than WHO standard by 15-28 dB and 19-23 dB respectively. The study showed that the authorities administration must take necessary procedures to reduce the noise levels in residential regions and in the regions surrounding the hospitals. (author)

  16. A practical exposure-equivalent metric for instrumentation noise in x-ray imaging systems

    International Nuclear Information System (INIS)

    Yadava, G K; Kuhls-Gilcrist, A T; Rudin, S; Patel, V K; Hoffmann, K R; Bednarek, D R

    2008-01-01

    The performance of high-sensitivity x-ray imagers may be limited by additive instrumentation noise rather than by quantum noise when operated at the low exposure rates used in fluoroscopic procedures. The equipment-invasive instrumentation noise measures (in terms of electrons) are generally difficult to make and are potentially not as helpful in clinical practice as would be a direct radiological representation of such noise that may be determined in the field. In this work, we define a clinically relevant representation for instrumentation noise in terms of noise-equivalent detector entrance exposure, termed the instrumentation noise-equivalent exposure (INEE), which can be determined through experimental measurements of noise-variance or signal-to-noise ratio (SNR). The INEE was measured for various detectors, thus demonstrating its usefulness in terms of providing information about the effective operating range of the various detectors. A simulation study is presented to demonstrate the robustness of this metric against post-processing, and its dependence on inherent detector blur. These studies suggest that the INEE may be a practical gauge to determine and compare the range of quantum-limited performance for clinical x-ray detectors of different design, with the implication that detector performance at exposures below the INEE will be instrumentation-noise limited rather than quantum-noise limited

  17. 33 CFR 149.697 - What are the requirements for a noise level survey?

    Science.gov (United States)

    2010-07-01

    ... and Equipment Noise Limits § 149.697 What are the requirements for a noise level survey? (a) A survey... measured over 12 hours to derive a time weighted average (TWA) using a sound level meter and an A-weighted filter or equivalent device. (c) If the noise level throughout a space is determined to exceed 85 db(A...

  18. Evaluation of the environmental noise levels in Abuja Municipality ...

    African Journals Online (AJOL)

    Objectives: To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. Methods: This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016.

  19. Statistics of A-weighted road traffic noise levels in shielded urban areas

    NARCIS (Netherlands)

    Forssén, J.; Hornikx, M.C.J.

    2006-01-01

    In the context of community noise and its negative effects, the noise descriptors used are usually long-term equivalent levels and, sometimes, maximum levels. An improved description could be achieved by including the time variations of the noise. Here, the time variations of A-weighted road traffic

  20. Noise Levels in Two Emergency Departments Before and After the Introduction of Electronic Whiteboards

    DEFF Research Database (Denmark)

    Hertzum, Morten

    2013-01-01

    . The maximum equivalent continuous noise levels across 1 second were above 80 dB(A) at all four coordination centres. At two of the centres above 80 dB(A) noises also occurred at night. After the introduction of electronic whiteboards the noise level was lowered at one ED but unchanged at the other ED...

  1. LOW-NOISE PAVEMENT AS A WAY OF LIMITATION OF TRAFFIC NOISE LEVEL

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2014-11-01

    Full Text Available Road surface can significantlyreduce the trafficnoise level. Depending on the characteristic of the upper surface layers the differences between the maximum rolling noise levels from passing vehicles to reach values about 10 dB (A. A special group is low-noise pavements characterized by the presence of voids above 15%. Application the porous asphalt layers or asphalt mixture type BBTM affects a significantreduction the width of land surrounded the roads where permissible equivalent sound level is exceeded. Such solutions in some cases can replace acoustic barriers. Road pavements with a higher content of voids require proper maintenance because their acoustic performances are reduced during operation.

  2. Practical ranges of loudness levels of various types of environmental noise, including traffic noise, aircraft noise, and industrial noise

    NARCIS (Netherlands)

    Salomons, E.M.; Janssen, S.A.

    2011-01-01

    In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a

  3. Practical Ranges of Loudness Levels of Various Types of Environmental Noise, Including Traffic Noise, Aircraft Noise, and Industrial Noise

    Directory of Open Access Journals (Sweden)

    Sabine A. Janssen

    2011-05-01

    Full Text Available In environmental noise control one commonly employs the A-weighted sound level as an approximate measure of the effect of noise on people. A measure that is more closely related to direct human perception of noise is the loudness level. At constant A-weighted sound level, the loudness level of a noise signal varies considerably with the shape of the frequency spectrum of the noise signal. In particular the bandwidth of the spectrum has a large effect on the loudness level, due to the effect of critical bands in the human hearing system. The low-frequency content of the spectrum also has an effect on the loudness level. In this note the relation between loudness level and A-weighted sound level is analyzed for various environmental noise spectra, including spectra of traffic noise, aircraft noise, and industrial noise. From loudness levels calculated for these environmental noise spectra, diagrams are constructed that show the relation between loudness level, A‑weighted sound level, and shape of the spectrum. The diagrams show that the upper limits of the loudness level for broadband environmental noise spectra are about 20 to 40 phon higher than the lower limits for narrowband spectra, which correspond to the loudness levels of pure tones. The diagrams are useful for assessing limitations and potential improvements of environmental noise control methods and policy based on A-weighted sound levels.

  4. Nuisance levels of noise effects radiologists' performance

    Science.gov (United States)

    McEntee, Mark F.; Coffey, Amina; Ryan, John; O'Beirne, Aaron; Toomey, Rachel; Evanoff, Micheal; Manning, David; Brennan, Patrick C.

    2010-02-01

    This study aimed to measure the sound levels in Irish x-ray departments. The study then established whether these levels of noise have an impact on radiologists performance Noise levels were recorded 10 times within each of 14 environments in 4 hospitals, 11 of which were locations where radiologic images are judged. Thirty chest images were then presented to 26 senior radiologists, who were asked to detect up to three nodular lesions within 30 posteroanterior chest x-ray images in the absence and presence of noise at amplitude demonstrated in the clinical environment. The results demonstrated that noise amplitudes rarely exceeded that encountered with normal conversation with the maximum mean value for an image-viewing environment being 56.1 dB. This level of noise had no impact on the ability of radiologists to identify chest lesions with figure of merits of 0.68, 0.69, and 0.68 with noise and 0.65, 0.68, and 0.67 without noise for chest radiologists, non-chest radiologists, and all radiologists, respectively. the difference in their performance using the DBM MRMC method was significantly better with noise than in the absence of noise at the 90% confidence interval (p=0.077). Further studies are required to establish whether other aspects of diagnosis are impaired such as recall and attention and the effects of more unexpected noise on performance.

  5. Automated system for equivalent noise charge measurements from 10 ns to 10 μs

    International Nuclear Information System (INIS)

    La Taille, C. de.

    1992-07-01

    Noise measurements versus filter time constant constitute a very powerful method to investigate series, parallel and 1/f noise contributions in front end electronics. Usually performed with a set of filters and a multichannel analyser, they are tedious and often limited to values greater than 100 ns. A very low noise bipolar filter is described whose time constant can be selected via GPIB bus from 10 ns to 10 μs in 10 steps. The data are transferred from a digital scope to a computer which generates a baseline histogram and determines the overall gain. The Equivalent Noise Charge is then calculated for each time constant and a fit to the results determines the various noise parameters. (author) 13 refs., 10 figs., 1 tab

  6. Accurate Prediction of Transimpedances and Equivalent Input Noise Current Densities of Tuned Optical Receiver Front Ends

    DEFF Research Database (Denmark)

    Liu, Qing Zhong

    1991-01-01

    Novel analytical expressions have been derived for calculating transimpedances and equivalent input noise current densities of five tuned optical receiver front ends based on PIN diode and MESFETs or HEMTs. Miller's capacitance, which has been omitted in previous studies, has been taken...

  7. Subjective annoyance caused by indoor low-level and low frequency noise and control method

    Institute of Scientific and Technical Information of China (English)

    DI Guo-qing; ZHANG Bang-jun; SHANG Qi

    2005-01-01

    The influence of low-level noise has not been widely noticed. This paper discovered that low-level and low frequency noise(Aweighted equivalent level Leq < 45 dB) causes higher probability of subjective annoyance. The fuzzy mathematic principle was applied to deal with the threshold level of subjective annoyance from noise in this study; there is preferable relationship between the indoor noise and noise annoyance at low frequency noise level. Study indicated at the same centered noise level, the change of annoyance probability is mainly caused by the change of the frequency spectrum characteristic of the indoor noise. Under low noise level environment, without change of the medium-low frequency noise, the slight increase of medium-high frequency noise level with the help of noise sheltering effect can significantly reduce the noise annoyance. This discovery brings a new resolution on how to improve the environmental quality of working or living places. A noise control model is given in this study according to the acoustic analysis.

  8. Ambient noise levels in the Taiwan region

    Science.gov (United States)

    Liang, W.; Liu, C.; Chen, R.; Huang, B.; Wu, F. T.; Wang, C.

    2008-12-01

    To characterize the island-wide background seismic noise in Taiwan, we estimate the power spectral density (PSD) at broadband stations of both the BATS (Broadband Array in Taiwan for Seismology) and the TAIGER experiment (Apr. 2006~Apr. 2008) for periods ranging from ~0.2 to 100 seconds. A new approach to calculate the probability density functions of noise power (PDFs, MaNamara and Buland, 2004) is used in this study. The results indicate that the cultural noise at higher frequencies is significant at populated area, which shows diurnal and weekly variation as what we expected. The noise power for microseisms centered at a period of ~5 seconds around the western costal plain show ~20dB higher than what observed at eastern Taiwan. This observation supports the inference that the coastal regions having narrow shelf with irregular coastlines are know to be especially efficient at radiating the predominat microseisms. Results from the linear array across central Taiwan demonstrate that the average noise power is quietest at the eastern Central Range. We have mapped the PDF mode for stations at various periods to see the spatial distribution of ambient noise levels, which could be used as the basic information for future station siting. Temporal variation of noise PSD is also present to provide a quantitative description of the seismic data quality collected by both BATS and TAIGER experiment. Some operational problems like base tilt, sensitivity change can be identified easily as well.

  9. Noise equivalent count measurements in a neuro-PET scanner with retractable septa

    International Nuclear Information System (INIS)

    Bailey, D.L.; Jones, T.; Spinks, T.J.; Gilardi, M.C.; Townsend, D.W.

    1990-01-01

    This paper reports on the removal of interplane septa in a PET scanner that enables acquisition of all possible lines of response (3D mode) in an effort to maximize the available number of detected events. One problem with this method at high countrates, however, is a markedly increased deadtime and randoms rate, which has a deleterious effect on data quality. The noise-equivalent countrate (NEC) performance of a neuro-PET scanner has been determined with and without interplane septa on uniform cylindrical phantoms of differing radii and in human studies to assess the optimum countrate conditions that realize the maximum gain. In the brain, the effective gain in NEC performance for 3D ranges from >5 at low countrates to ∼3.3 at 200 kcps (equivalent to 37 kcps in 2D). The gains of the 3D method assessed by this analysis are significant, and are shown to be highly dependent on countrate and object dimensions

  10. Seismic noise level variation in South Korea

    Science.gov (United States)

    Sheen, D.; Shin, J.

    2008-12-01

    The variations of seismic background noise in South Korea have been investigated by means of power spectral analysis. The Korea Institute of Geoscience and Mineral Resources (KIGAM) and the Korea Meteorological Administation (KMA) have national wide seismic networks in South Korea, and, in the end of 2007, there are 30 broadband stations which have been operating for more than a year. In this study, we have estimated the power spectral density of seismic noise for 30 broadband stations from 2005 to 2007. Since we estimate PSDs from a large dataset of continuous waveform in this study, a robust PSD estimate of McNamara and Buland (2004) is used. In the frequency range 1-5 Hz, the diurnal variations of noise are observed at most of stations, which are especially larger at coastal stations and at insular than at inland. Some stations shows daily difference of diurnal variations, which represents that cultural activities contribute to the noise level of a station. The variation of number of triggered stations, however, shows that cultural noise has little influence on the detection capability of seismic network in South Korea. Seasonal variations are observed well in the range 0.1-0.5 Hz, while much less found in the frequency range 1-5 Hz. We observed that strong peaks in the range 0.1-0.5 Hz occur at the summer when Pacific typhoons are close to the Korean Peninsula.

  11. The influence of subway station design on noise levels.

    Science.gov (United States)

    Shah, Ravi R; Suen, Jonathan J; Cellum, Ilana P; Spitzer, Jaclyn B; Lalwani, Anil K

    2017-05-01

    To investigate the impact of subway station design on platform noise levels. Observational. Continuous A-weighted decibel (dBA) sound levels were recorded in 20 New York City subway stations, where trains entered on either a straight track or curved track in 10 stations each. Equivalent continuous noise levels (L eq ) at various locations on the boarding platform (inbound end, midplatform, and outbound end) during train entry and exit were compared between the straight and curved stations in broadband as well as narrow one-third octave bands. Overall, curved stations trended louder than straight stations, although the difference in broadband L eq did not reach statistical significance (curve, 83.4 dBA; straight, 82.6 dBA; P = .054). Noise levels were significantly louder at the inbound end of the platform during train entry (inbound, 89.7 dBA; mid, 85.5 dBA; outbound, 78.7 dBA; P < .001) and at the outbound end during train exit (inbound, 79.7 dBA; mid, 85.3 dBA; outbound, 89.1 dBA; P < .001). Narrow band analysis showed that curved stations were significantly louder than straight stations at 100 Hz and high frequencies from 8 to 20 kHz. Peak impact levels ranged from 104 to 121 dBA. Curved stations have a different noise profile compared to straight stations and are significantly louder than straight stations at high frequencies. Designing stations with straight tracks within the platform can help reduce commuter noise exposure. NA Laryngoscope, 127:1169-1174, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Equivalence of velocity-level and acceleration-level redundancy-resolution of manipulators

    International Nuclear Information System (INIS)

    Cai Binghuang; Zhang Yunong

    2009-01-01

    The equivalence of velocity-level and acceleration-level redundancy resolution of robot manipulators is investigated in this Letter. Theoretical analysis based on gradient-descent method and computer simulations based on PUMA560 robot manipulator both demonstrate the equivalence of redundancy-resolution schemes at different levels.

  13. Noise level in neonatal incubators: A comparative study of three models.

    Science.gov (United States)

    Fernández Zacarías, F; Beira Jiménez, J L; Bustillo Velázquez-Gaztelu, P J; Hernández Molina, R; Lubián López, Simón

    2018-04-01

    Preterm infants usually have to spend a long time in an incubator, excessive noise in which can have adverse physiological and psychological effects on neonates. In fact, incubator noise levels typically range from 45 to 70 dB but differences in this respect depend largely on the noise measuring method used. The primary aim of this work was to assess the extent to which noise in an incubator comes from its own fan and how efficiently the incubator can isolate external noise. Three different incubator models were characterized for acoustic performance by measuring their internal noise levels in an anechoic chamber, and also for noise isolation efficiency by using a pink noise source in combination with an internal and an external microphone that were connected to an SVAN958 noise analyzer. The incubators studied produced continuous equivalent noise levels of 53.5-58 dB and reduced external noise by 5.2-10.4 dB. A preterm infant in an incubator is exposed to noise levels clearly exceeding international recommendations even though such levels usually comply with the limit set in the standard IEC60601-2-19: 2009 (60 dBA) under normal conditions of use. Copyright © 2018. Published by Elsevier B.V.

  14. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels.

    Science.gov (United States)

    Ragettli, Martina S; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-12-29

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels-LAeq24h and day-evening-night equivalent noise levels-Lden) for each study participant was determined using a statistical noise model (land use regression-LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07-1.13) and 1.04 (1.02-1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  15. Noise pollution levels in the pediatric intensive care unit.

    Science.gov (United States)

    Kramer, Bree; Joshi, Prashant; Heard, Christopher

    2016-12-01

    Patients and staff may experience adverse effects from exposure to noise. This study assessed noise levels in the pediatric intensive care unit and evaluated family and staff opinion of noise. Noise levels were recorded using a NoisePro DLX. The microphone was 1 m from the patient's head. The noise level was averaged each minute and levels above 70 and 80 dBA were recorded. The maximum, minimum, and average decibel levels were calculated and peak noise level great than 100 dBA was also recorded. A parent questionnaire concerning their evaluation of noisiness of the bedside was completed. The bedside nurse also completed a questionnaire. The average maximum dB for all patients was 82.2. The average minimum dB was 50.9. The average daily bedside noise level was 62.9 dBA. The average % time where the noise level was higher than 70 dBA was 2.2%. The average percent of time that the noise level was higher than 80 dBA was 0.1%. Patients experienced an average of 115 min/d where peak noise was greater than 100 dBA. The parents and staff identified the monitors as the major contribution to noise. Patients experienced levels of noise greater than 80 dBA. Patients experience peak noise levels in excess of 100 dB during their pediatric intensive care unit stay. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Diversity, variation and fairness: Equivalence in national level language assessments

    Directory of Open Access Journals (Sweden)

    Albert Weideman

    2017-03-01

    Full Text Available The post-1994 South African constitution proudly affirms the language diversity of the country, as do subsequent laws, while ministerial policies, both at further and higher education level, similarly promote the use of all 11 official languages in education. However, such recognition of diversity presents several challenges to accommodate potential variation. In language education at secondary school, which is nationally assessed, the variety being promoted immediately raises issues of fairness and equivalence. The final high-stakes examination of learners’ ability in home language at the exit level of their pre-tertiary education is currently contentious in South Africa. It is known, for example, that in certain indigenous languages, the exit level assessments barely discriminate among learners with different abilities, while in other languages they do. For that reason, the Council for Quality Assurance in General and Further Education, Umalusi, has commissioned several reports to attempt to understand the nature of the problem. This article will deal with a discussion of a fourth attempt by Umalusi to solve the problem. That attempt, undertaken by a consortium of four universities, has already delivered six interim reports to this statutory body, and the article will consider some of their content and methodology. In their reconceptualisation of the problem, the applied linguists involved first sought to identify the theoretical roots of the current curriculum in order to articulate more sharply the construct being assessed. That provides the basis for a theoretical justification of the several solutions being proposed, as well as for the preliminary designs of modifications to current, and the introduction of new assessments. The impact of equivalence of measurement as a design requirement will be specifically discussed, with reference to the empirical analyses of results of a number of pilots of equivalent tests in different languages.

  17. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels

    Directory of Open Access Journals (Sweden)

    Martina S. Ragettli

    2015-12-01

    Full Text Available There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels—LAeq24h and day-evening-night equivalent noise levels—Lden for each study participant was determined using a statistical noise model (land use regression—LUR that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR for highly disturbed people of 1.10 (95% CI: 1.07–1.13 and 1.04 (1.02–1.06 per 1 dB(A Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

  18. Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels

    Science.gov (United States)

    Ragettli, Martina S.; Goudreau, Sophie; Plante, Céline; Perron, Stéphane; Fournier, Michel; Smargiassi, Audrey

    2015-01-01

    There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels—LAeq24h and day-evening-night equivalent noise levels—Lden) for each study participant was determined using a statistical noise model (land use regression—LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07–1.13) and 1.04 (1.02–1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic. PMID:26729143

  19. Noise level in a pediatric intensive care unit.

    Science.gov (United States)

    Carvalho, Werther B; Pedreira, Mavilde L G; de Aguiar, Maria Augusta L

    2005-01-01

    The purpose of this study was to verify the noise level at a PICU. This prospective observational study was performed in a 10 bed PICU at a teaching hospital located in a densely populated district within the city of São Paulo, Brazil. Sound pressure levels (dBA) were measured 24 hours during a 6-day period. Noise recording equipment was placed in the PICU access corridor, nursing station, two open wards with three and five beds, and in isolation rooms. The resulting curves were analyzed. A basal noise level variation between 60 and 70 dBA was identified, with a maximum level of 120 dBA. The most significant noise levels were recorded during the day and were produced by the staff. The basal noise level identified exceeds International Noise Council recommendations. Education regarding the effects of noise on human hearing and its relation to stress is the essential basis for the development of a noise reduction program.

  20. A simplified, improved method for making amplifier equivalent noise charge measurements using a new generation digitizing oscilloscope

    International Nuclear Information System (INIS)

    Zimmerman, T.

    1990-10-01

    Historically a variety of methods have been used to measure the equivalent noise charge (ENC) of amplifier/shaper systems for high energy physics. Some of these methods require several pieces of special test equipment and a fair amount of effort. The advent of digitizing oscilloscopes with statistics capabilities makes it possible to perform certain types of noise measurements accurately with very little effort. This paper describes the noise measurement method of a time invariant amplifier/shaper and of a time variant correlated sampling system, using a Tektronix DSA602 Digitizing Signal Analyzer. 4 figs

  1. Existing Noise Level at Railway Stations in Malaysia

    Directory of Open Access Journals (Sweden)

    Shahidan Shahiron

    2017-01-01

    Full Text Available Railway transportation known as one of the most environmental friendly transportation mode. However, the significance problems of railway transportation are noise pollution and negatively impact the wellbeing of the whole community. Unfortunately, there has been lack of public awareness about the noise level produce by the railway transportation in Malaysia. This study investigates the noise level produced by railway transportation in Malaysia specifically by Keretapi Tanah Melayu Berhad (KTMB. Methods of collecting existing noise level at railway stations in Malaysia are briefly discussed in this study. The finding indicates that the noise level produced by the railway transportation in Malaysia which is by KTMB is considered as dangerous to human being and also exceed the noise limit that has been assigned by Department of Environment Ministry of Natural Resources and Environment of Malaysia. A better noise barrier and improved material should be developed to mitigate the existing noise level produced by railway transportations in Malaysia.

  2. Some insights into the relationship between urban air pollution and noise levels.

    Science.gov (United States)

    Kim, Ki-Hyun; Ho, Duy Xuan; Brown, Richard J C; Oh, J-M; Park, Chan Goo; Ryu, In Cheol

    2012-05-01

    The relationship between noise and air pollution was investigated in eight different districts across Seoul, Korea, between September and November 2010. The noise levels in each district were measured at both roadside and non-roadside locations. It was found that the maximum levels of noise were generally at frequencies of around 1000 Hz. The equivalent noise levels (L(eq)), over all districts, averaged 61.4 ± 7.36 dB which is slightly lower than the noise guidelines set by the World Health Organization (WHO) of 70 dB for industrial, commercial, traffic, and outdoor areas. Comparison of L(eq) levels in each district consistently indicates that noise levels are higher at roadside sites than non-roadside sites. In addition the relative dominance of noise during daytime as compared to nighttime was also apparent. Moreover, the results of an analysis relating sound levels with air pollutant levels indicate strongly that the correlation between these two parameters is the strongest at roadside sites (relative to non-roadside sites) and during nighttime (relative to daytime). The results of our data analysis point to a positive, but complex, correlation between noise levels and air pollution. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Unified analytical expressions for calculating resonant frequencies, transimpedances, and equivalent input noise current densities of tuned receiver front ends

    DEFF Research Database (Denmark)

    Liu, Qing Zhong

    1992-01-01

    Unified analytical expressions have been derived for calculating the resonant frequencies, transimpedance and equivalent input noise current densities of the four most widely used tuned optical receiver front ends built with FETs and p-i-n diodes. A more accurate FET model has been used to improve...

  4. [Noise level in a care and teaching hospital institution].

    Science.gov (United States)

    Mendoza-Sánchez, R S; Roque-Sánchez, R H; Moncada-González, B

    1996-01-01

    Noise in the environment is increasing over the years. Disturbances produced by noise are varied, some lead to serious health consequences. Noise level was registered in a teaching hospital. Levels in the wards were between 50 and 59 dB. In the Intensive Care Unit, main hallways and outpatients department levels were higher than 59 dB. Isolated peaks up to 90.0 dB (Pediatrics) were detected. The noise level recommended for a hospital is under 50.0 dB. We found that the principal source of noise came from the medical and nursing staff.

  5. Noise level and MPEG-2 encoder statistics

    Science.gov (United States)

    Lee, Jungwoo

    1997-01-01

    Most software in the movie and broadcasting industries are still in analog film or tape format, which typically contains random noise that originated from film, CCD camera, and tape recording. The performance of the MPEG-2 encoder may be significantly degraded by the noise. It is also affected by the scene type that includes spatial and temporal activity. The statistical property of noise originating from camera and tape player is analyzed and the models for the two types of noise are developed. The relationship between the noise, the scene type, and encoder statistics of a number of MPEG-2 parameters such as motion vector magnitude, prediction error, and quant scale are discussed. This analysis is intended to be a tool for designing robust MPEG encoding algorithms such as preprocessing and rate control.

  6. The research on noise equivalent quanta and detective quantum efficiency of screen-film system

    International Nuclear Information System (INIS)

    Xie Jingdong; Wang Changyuan; Yuan Yude; Zhang Menglong; Wang Jian; Zheng Hao; Sun Yong

    2002-01-01

    Objective: To examine the noise equivalent quanta (NEQ) and detective quantum efficiency (DQE) of screen-film system. Methods: Green 400 screen-Kodak film and CaWO 4 screen-Fuji film were used in the study. The characteristic curves were obtained by distance method. The square wave technique was employed to determine the modulation transfer function (MTF). The Wiener spectrum (WS) was determined by Fourier analysis on uniformly exposed films. The NEQ and DQE were calculated from the characteristic curve slope, MTF, and WS measurements. Results: (1) The NEQ value of Green 400 screen-Kodak film system was 1.48 x 10 6 mm -2 when the spatial frequency was 0.6 cycles/mm, and it was 0.65 times larger than that of CaWO 4 screen-Fuji film system; The NEQ value of Green 400 screen-Kodak film system was 0.329 x 10 4 mm -2 when the spatial frequency was 4.0 cycles/mm, and it was 1.55 times larger than that of CaWO 4 screen-Fuji film system. (2) The DQE value of Green 400 screen-Kodak film system was 0.224 when the spatial frequency was 0.6 cycles/mm, and it was 1.6 times larger than that of CaWO 4 screen-Fuji film system; The DQE value of Green 400 screen-Kodak film system was 0.052 when the spatial frequency was 4.0 cycles/mm, and it was 3.7 times larger than that of CaWO 4 screen-Fuji film system. Conclusion: The Green 400 Screen-Kodak film system has superior NEQ when the spatial frequency was more than 3.0 cycles/mm and has superior DQE among the total spatial frequency in comparison with CaWO 4 screen-Fuji film system

  7. Adaptive EMG noise reduction in ECG signals using noise level approximation

    Science.gov (United States)

    Marouf, Mohamed; Saranovac, Lazar

    2017-12-01

    In this paper the usage of noise level approximation for adaptive Electromyogram (EMG) noise reduction in the Electrocardiogram (ECG) signals is introduced. To achieve the adequate adaptiveness, a translation-invariant noise level approximation is employed. The approximation is done in the form of a guiding signal extracted as an estimation of the signal quality vs. EMG noise. The noise reduction framework is based on a bank of low pass filters. So, the adaptive noise reduction is achieved by selecting the appropriate filter with respect to the guiding signal aiming to obtain the best trade-off between the signal distortion caused by filtering and the signal readability. For the evaluation purposes; both real EMG and artificial noises are used. The tested ECG signals are from the MIT-BIH Arrhythmia Database Directory, while both real and artificial records of EMG noise are added and used in the evaluation process. Firstly, comparison with state of the art methods is conducted to verify the performance of the proposed approach in terms of noise cancellation while preserving the QRS complex waves. Additionally, the signal to noise ratio improvement after the adaptive noise reduction is computed and presented for the proposed method. Finally, the impact of adaptive noise reduction method on QRS complexes detection was studied. The tested signals are delineated using a state of the art method, and the QRS detection improvement for different SNR is presented.

  8. Assessment of noise level and noise propagation generated by light-lift helicopters in mountain natural environments.

    Science.gov (United States)

    Grigolato, Stefano; Mologni, Omar; Proto, Andrea Rosario; Zimbalatti, Giuseppe; Cavalli, Raffaele

    2018-01-20

    The use of helicopter rises discussion about environmental noise propagation especially when it operates in proximity of environmentally sensitive areas (ESAs) for an extended period because of its potential implications in wildlife behaviours. In order to support decisions on helicopter logging operation management in proximity of ESAs, this study focused on (i) analysing the noise spectrum of a light-lift helicopter during logging operations and on (ii) assessing the noise propagation in the surrounding environments. This study investigated a helicopter logging operation for wood fuel extraction in the eastern part of the Italian Alps. The potential disturbance area covered for the entire helicopter logging operation was evaluated by a specific GIS application according to hearing sensitivity of the most sensitive wildlife species in the study area (different strigiform species). The noise level at the ground appeared to be affected by the location regardless both the use of equivalent continuous sound pressures level dB(A) (LAeq) and the single-event level (SEL) noise metrics. The lowest values were recorded when the helicopter was flown over the sound meter level located under the forest canopy, while the highest was recorded when the helicopter was unhooking the loads at the landing. The GIS application highlighted the consistent of the exceeded noise area (weighted to strigiform hearing range and sensitivity) for the lower frequency bands (0.016-0.250 kHz). A more restricted exceeded noise area concerned instead the most sensitive frequency bands" for the strigiform (1-2 kHz). Graphical abstract ᅟ.

  9. Noise levels, noise annoyance, and hearing-related problems in a dental college.

    Science.gov (United States)

    Ahmed, Hafiz Omer; Ali, Wesal Jasim

    2017-05-04

    Through a cross-sectional survey and integrated sound level meter, this research examined noise exposure and auditory- and nonauditory-related problems experienced by students of a dentistry college located in the United Arab Emirates (UAE). A structured interview questionnaire was used to examine hearing-related problems, noise annoyance, and awareness of 114 students toward noise. The results showed that maximum noise levels were between 65 and 79 dB(A) with peak levels (high and low frequencies) ranging between 89 and 93 dB(A). Around 80% of the students experienced a certain degree of noise annoyance; 54% reported one of the hearing-related problems; and about 10% claimed to have hearing loss to a certain extent. It is recommended that sound-absorbent materials be used during the construction of dental clinics and laboratories to reduce the noise levels.

  10. Evaluation of noise pollution level based upon community exposure and response data

    Science.gov (United States)

    Edmiston, R. D.

    1972-01-01

    The results and procedures are reported from an evaluation of noise pollution level as a predictor of annoyance, based on aircraft noise exposure and community response data. The measures of noise exposure presented include composite noise rating, noise exposure forecast, noise and number index. A proposed measure as a universal noise exposure measure for noise pollution level (L sub NP) is discussed.

  11. Definition of 1992 Technology Aircraft Noise Levels and the Methodology for Assessing Airplane Noise Impact of Component Noise Reduction Concepts

    Science.gov (United States)

    Kumasaka, Henry A.; Martinez, Michael M.; Weir, Donald S.

    1996-01-01

    This report describes the methodology for assessing the impact of component noise reduction on total airplane system noise. The methodology is intended to be applied to the results of individual study elements of the NASA-Advanced Subsonic Technology (AST) Noise Reduction Program, which will address the development of noise reduction concepts for specific components. Program progress will be assessed in terms of noise reduction achieved, relative to baseline levels representative of 1992 technology airplane/engine design and performance. In this report, the 1992 technology reference levels are defined for assessment models based on four airplane sizes - an average business jet and three commercial transports: a small twin, a medium sized twin, and a large quad. Study results indicate that component changes defined as program final goals for nacelle treatment and engine/airframe source noise reduction would achieve from 6-7 EPNdB reduction of total airplane noise at FAR 36 Stage 3 noise certification conditions for all of the airplane noise assessment models.

  12. Investigations of internal noise levels for different target sizes, contrasts, and noise structures

    Science.gov (United States)

    Han, Minah; Choi, Shinkook; Baek, Jongduk

    2014-03-01

    To describe internal noise levels for different target sizes, contrasts, and noise structures, Gaussian targets with four different sizes (i.e., standard deviation of 2,4,6 and 8) and three different noise structures(i.e., white, low-pass, and highpass) were generated. The generated noise images were scaled to have standard deviation of 0.15. For each noise type, target contrasts were adjusted to have the same detectability based on NPW, and the detectability of CHO was calculated accordingly. For human observer study, 3 trained observers performed 2AFC detection tasks, and correction rate, Pc, was calculated for each task. By adding proper internal noise level to numerical observer (i.e., NPW and CHO), detectability of human observer was matched with that of numerical observers. Even though target contrasts were adjusted to have the same detectability of NPW observer, detectability of human observer decreases as the target size increases. The internal noise level varies for different target sizes, contrasts, and noise structures, demonstrating different internal noise levels should be considered in numerical observer to predict the detection performance of human observer.

  13. Noise Levels in Dental Offices and Laboratories in Hamedan, Iran

    Directory of Open Access Journals (Sweden)

    F. Mojarad

    2009-12-01

    Full Text Available Objective: Noise pollution is one of the most important situations requiring a solution by the contemporary world. The National Institute for Occupational Safety and Health has identified noise as one of the ten leading causes of work-related diseases and injuries.Dentists and dental auxiliaries are exposed to different noise levels while working in dental offices or laboratories. The purpose of this study was to measure the noise level made by different dental instruments in dental offices and laboratories.Materials and Methods: Measurement of the noise level was performed in 89 dental offices and nine dental laboratories. The noise levels were determined using a sound level meter; type SL-4011(Lutron ,which was placed at the operator’s ear level in dental offices and laboratories and also at two-meter distance from the technician’s ear in laboratories.Results: The maximum sound level was 85.8 dB in dental offices and 92.0 dB in laboratories.In dental clinics, the highest noise was produced by the ultrasonic-scaler (85.8 dB and the lowest noise (49.7 dB by the high-volume aspirator, whereas in the laboratory,the highest noise was caused during grinding by the stonecutter (92.0 dB and the lowest by the denture-polishing unit (41.0 dB.Conclusion: After close evaluation, we believe that the maximum noise level in dental offices, although often beneath the damaging noise level for the human ear, is very close to the limit of hearing loss (85.0 dB. However, laboratory technicians may be at risk ifthey choose not to wear ear protection (earplugs or earmuffs.

  14. Predictive modelling of noise level generated during sawing of rocks

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated during of rock sawing by circular diamond sawblades. Influence of the operating variables and rock properties on the noise level are investigated and analysed. Statistical analyses are then employed and models are built for the prediction of ...

  15. Profiles of noise exposure levels in South African mining

    CSIR Research Space (South Africa)

    Edwards, A

    2011-05-01

    Full Text Available were exposed to noise levels of above the 85 dBA legislated occupational exposure level. The conclusion was made that information obtained through the study could be developed into a national personal noise exposure database, including audiometric...

  16. Pilot survey of subway and bus stop noise levels.

    Science.gov (United States)

    Gershon, Robyn R M; Neitzel, Richard; Barrera, Marissa A; Akram, Muhammad

    2006-09-01

    Excessive noise exposure is a serious global urban health problem, adversely affecting millions of people. One often cited source of urban noise is mass transit, particularly subway systems. As a first step in determining risk within this context, we recently conducted an environmental survey of noise levels of the New York City transit system. Over 90 noise measurements were made using a sound level meter. Average and maximum noise levels were measured on subway platforms, and maximum levels were measured inside subway cars and at several bus stops for comparison purposes. The average noise level measured on the subway platforms was 86 +/- 4 dBA (decibel-A weighting). Maximum levels of 106, 112, and 89 dBA were measured on subway platforms, inside subway cars, and at bus stops, respectively. These results indicate that noise levels in subway and bus stop environments have the potential to exceed recommended exposure guidelines from the World Health Organization (WHO) and U.S. Environmental Protection Agency (EPA), given sufficient exposure duration. Risk reduction strategies following the standard hierarchy of control measures should be applied, where feasible, to reduce subway noise exposure.

  17. REDUCTION OF CLASSROOM NOISE LEVELS USING GROUP CONTINGENCIES

    OpenAIRE

    Ring, Brandon M.; Sigurdsson, Sigurdur O.; Eubanks, Sean L.; Silverman, Kenneth

    2014-01-01

    The therapeutic workplace is an employment-based abstinence reinforcement intervention for unemployed drug users where trainees receive on-the-job employment skills training in a classroom setting. The study is an extension of prior therapeutic workplace research, which suggested that trainees frequently violated noise standards. Participants received real-time graphed feedback of noise levels and had the opportunity to earn monetary group reinforcement for maintaining a low number of noise v...

  18. Training Methods for Image Noise Level Estimation on Wavelet Components

    Directory of Open Access Journals (Sweden)

    A. De Stefano

    2004-12-01

    Full Text Available The estimation of the standard deviation of noise contaminating an image is a fundamental step in wavelet-based noise reduction techniques. The method widely used is based on the mean absolute deviation (MAD. This model-based method assumes specific characteristics of the noise-contaminated image component. Three novel and alternative methods for estimating the noise standard deviation are proposed in this work and compared with the MAD method. Two of these methods rely on a preliminary training stage in order to extract parameters which are then used in the application stage. The sets used for training and testing, 13 and 5 images, respectively, are fully disjoint. The third method assumes specific statistical distributions for image and noise components. Results showed the prevalence of the training-based methods for the images and the range of noise levels considered.

  19. evaluation of the environmental noise levels in abuja municipality

    African Journals Online (AJOL)

    ABSTRACT. Background: Noise remains a nuisance which impacts negatively on the ..... Furthermore, Erikson et al postulated that a persistent noise level .... Hessel PA, Sluis-Cremer G K. Hearing loss in ... Ear & Hearing 2006; 27(1): 1-19. 13.

  20. Can weekly noise levels of urban road traffic, as predominant noise source, estimate annual ones?

    Science.gov (United States)

    Prieto Gajardo, Carlos; Barrigón Morillas, Juan Miguel; Rey Gozalo, Guillermo; Vílchez-Gómez, Rosendo

    2016-11-01

    The effects of noise pollution on human quality of life and health were recognised by the World Health Organisation a long time ago. There is a crucial dilemma for the study of urban noise when one is looking for proven methodologies that can allow, on the one hand, an increase in the quality of predictions, and on the other hand, saving resources in the spatial and temporal sampling. The temporal structure of urban noise is studied in this work from a different point of view. This methodology, based on Fourier analysis, is applied to several measurements of urban noise, mainly from road traffic and one-week long, carried out in two cities located on different continents and with different sociological life styles (Cáceres, Spain and Talca, Chile). Its capacity to predict annual noise levels from weekly measurements is studied. The relation between this methodology and the categorisation method is also analysed.

  1. Critical assessment of day time traffic noise level at curbside open-air microenvironment of Kolkata City, India.

    Science.gov (United States)

    Kundu Chowdhury, Anirban; Debsarkar, Anupam; Chakrabarty, Shibnath

    2015-01-01

    The objective of the research work is to assess day time traffic noise level at curbside open-air microenvironment of Kolkata city, India under heterogeneous environmental conditions. Prevailing traffic noise level in terms of A-weighted equivalent noise level (Leq) at the microenvironment was in excess of 12.6 ± 2.1 dB(A) from the day time standard of 65 dB(A) for commercial area recommended by the Central Pollution Control Board (CPCB) of India. Noise Climate and Traffic Noise Index of the microenvironment were accounted for 13 ± 1.8 dB(A) and 88.8 ± 6.1 dB(A) respectively. A correlation analysis explored that prevailing traffic noise level of the microenvironment had weak negative (-0.21; p air temperature and relative humidity. A Varimax rotated principal component analysis explored that motorized traffic volume had moderate positive loading with background noise component (L90, L95, L99) and prevailing traffic noise level had very strong positive loading with peak noise component (L1, L5, L10). Background and peak noise component cumulatively explained 80.98 % of variance in the data set. Traffic noise level at curbside open-air microenvironment of Kolkata City was higher than the standard recommended by CPCB of India. It was highly annoying also. Air temperature and relative humidity had little influence and the peak noise component had the most significant influence on the prevailing traffic noise level at curbside open-air microenvironment. Therefore, traffic noise level at the microenvironment of the city can be reduced with careful honking and driving.

  2. Predictive modelling of noise level generated during sawing of rocks ...

    Indian Academy of Sciences (India)

    This paper presents an experimental and statistical study on noise level generated .... hardness were determined according to related ISRM (1981) suggested methods. Thin section ..... tistical Package for the Social Sciences). Additionally, the ...

  3. Lateralization of noise bursts in interaurally correlated or uncorrelated background noise using interaural level differences.

    Science.gov (United States)

    Reed, Darrin K; van de Par, Steven

    2015-10-01

    The interaural level difference (ILD) of a lateralized target source may be effectively reduced when the target is presented together with background noise containing zero ILD. It is not certain whether listeners perceive a position congruent with the reduced ILD or the actual target ILD in a lateralization task. Two sets of behavioral experiments revealed that many listeners perceived a position at or even larger than that corresponding to the presented target ILD when a temporal onset/offset asynchrony between the broadband target and the broadband background noise was present. When no temporal asynchrony was present, however, the perceived lateral position indicated a dependency on the coherence of the background noise for several listeners. With interaurally correlated background noise, listeners reported a reduced ILD resulting from the combined target and background noise stimulus. In contrast, several of the listeners made a reasonable estimate of the position corresponding to the target ILD for interaurally uncorrelated, broadband, background noise. No obvious difference in performance was seen between low- or high-frequency stimuli. Extension of a weighting template to the output of a standard equalization-cancellation model was shown to remove a lateral bias on the predicted target ILD resulting from the presence of background noise. Provided that an appropriate weighting template is applied based on knowledge of the background noise coherence, good prediction of the behavioral data is possible.

  4. Reducing Indoor Noise Levels Using People's Perception on Greenery

    Science.gov (United States)

    Mediastika, Christina E.; Binarti, Floriberta

    2013-12-01

    Employees working in cubicles of open-plan offices in Indonesia were studied in regard to their perception on the ability of indoor greenery to reduce noise levels. Sansevieria trifasciata and Scindapsus sp were used. Each was placed in the cubicle and noise levels were measured without plants, with Sansevieria, and with Scindapsus in place. The meters showed very insignificant difference. However, responses to surveys indicated a perception of lower noise in the presence of greenery. This seemed to be supported by prior knowledge and preconception and may be useful in creating a "quieter" indoor environment.

  5. Pilot task-based assessment of noise levels among firefighters.

    Science.gov (United States)

    Neitzel, Rl; Hong, O; Quinlan, P; Hulea, R

    2013-11-01

    Over one million American firefighters are routinely exposed to various occupational hazards agents. While efforts have been made to identify and reduce some causes of injuries and illnesses among firefighters, relatively little has been done to evaluate and understand occupational noise exposures in this group. The purpose of this pilot study was to apply a task-based noise exposure assessment methodology to firefighting operations to evaluate potential noise exposure sources, and to use collected task-based noise levels to create noise exposure estimates for evaluation of risk of noise-induced hearing loss by comparison to the 8-hr and 24-hr recommended exposure limits (RELs) for noise of 85 and 80.3 dBA, respectively. Task-based noise exposures (n=100 measurements) were measured in three different fire departments (a rural department in Southeast Michigan and suburban and urban departments in Northern California). These levels were then combined with time-at-task information collected from firefighters to estimate 8-hr noise exposures for the rural and suburban fire departments (n=6 estimates for each department). Data from 24-hr dosimetry measurements and crude self-reported activity categories from the urban fire department (n=4 measurements) were used to create 24-hr exposure estimates to evaluate the bias associated with the task-based estimates. Task-based noise levels were found to range from 82-109 dBA, with the highest levels resulting from use of saws and pneumatic chisels. Some short (e.g., 30 min) sequences of common tasks were found to result in nearly an entire allowable daily exposure. The majority of estimated 8-hr and 24-hr exposures exceeded the relevant recommended exposure limit. Predicted 24-hr exposures showed substantial imprecision in some cases, suggesting the need for increased task specificity. The results indicate potential for overexposure to noise from a variety of firefighting tasks and equipment, and suggest a need for further

  6. METHODS OF NOISE LEVEL REDUCTION OF DRIVE IN LATHES

    Directory of Open Access Journals (Sweden)

    Janusz ROGULA

    2014-06-01

    Full Text Available The aim of this work is method presentation to noise level reduction of fixed headstock of the lathe. It is connected with the causes finding of non-uniform work of lathe headstock, description of recent design and its analysis. Problem of the excessive noise level concern to near 35% of the lathes have been produced. In spite of lack of noise reduction possibility there were no system solution of problem. Design optimisation weren’t done after application the electric motor with inverter. New solution of electric motor control let to reduce number of gear wheels in lathe drive system. For this drive solution there weren’t made the analysis of drive particular parts influence on the noise generation.

  7. Advanced supersonic propulsion study. [with emphasis on noise level reduction

    Science.gov (United States)

    Sabatella, J. A. (Editor)

    1974-01-01

    A study was conducted to determine the promising propulsion systems for advanced supersonic transport application, and to identify the critical propulsion technology requirements. It is shown that noise constraints have a major effect on the selection of the various engine types and cycle parameters. Several promising advanced propulsion systems were identified which show the potential of achieving lower levels of sideline jet noise than the first generation supersonic transport systems. The non-afterburning turbojet engine, utilizing a very high level of jet suppression, shows the potential to achieve FAR 36 noise level. The duct-heating turbofan with a low level of jet suppression is the most attractive engine for noise levels from FAR 36 to FAR 36 minus 5 EPNdb, and some series/parallel variable cycle engines show the potential of achieving noise levels down to FAR 36 minus 10 EPNdb with moderate additional penalty. The study also shows that an advanced supersonic commercial transport would benefit appreciably from advanced propulsion technology. The critical propulsion technology needed for a viable supersonic propulsion system, and the required specific propulsion technology programs are outlined.

  8. Anthropogenic noise alters bat activity levels and echolocation calls

    Directory of Open Access Journals (Sweden)

    Jessie P. Bunkley

    2015-01-01

    Full Text Available Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband noise 24 hours a day, 365 days a year. With over half a million producing gas wells in the U.S. this infrastructure is a major source of noise pollution across the landscape. We conducted a ‘natural experiment’ in the second largest gas extraction field in the U.S. to investigate the potential effects of gas compressor station noise on the activity levels of the local bat assemblage. We used acoustic monitoring to compare the activity level (number of minutes in a night with a bat call of the bat assemblage at sites with compressor stations to sites lacking this infrastructure. We found that activity levels for the Brazilian free-tailed bat (Tadarida brasiliensis were 40% lower at loud compressor sites compared to quieter well pads, whereas the activity levels of four other species (Myotis californicus, M. cillolabrum, M. lucifugus, Parastrellus hesperus were not affected by noise. Furthermore, our results reveal that the assemblage of bat species emitting low frequency (35 kHz echolocation did not exhibit altered activity levels in noise. Lower activity levels of Brazilian free-tailed bats at loud sites indicate a potential reduction in habitat for this species. Additionally, a comparison of echolocation search calls produced by free-tailed bats at sites with and without compressor stations reveal that this species modifies its echolocation search calls in noise—producing longer calls with a narrower bandwidth. Call alterations might affect prey

  9. Ambient noise levels and characterization in Aegean region, Turkey

    Science.gov (United States)

    Sevim, Fatih; Zor, Ekrem; Açıkgöz, Cem; Tarancıoğlu, Adil

    2018-03-01

    We assessed the ambient noise level in the Aegean region and analyzed its diurnal variation and its relation to the earthquake detection capability of the Aegean Region Seismic Network (ARSN). We prepared probability density functions (PDFs) for 19 broadband stations in the Aegean region operated by the Earth and Marine Sciences Institute (EMSI) of the Marmara Research Center (MRC) of the Turkish Scientific Research Council (TÜBİTAK). The power spectral densities (PSDs) used to construct PDFs for each station were computed for the periods between 0.02 and 180 s. In addition, we generated noise map of the Aegean region for different periods using the PDFs to assess the origin of the noise. We analyzed earthquake activity in the region and found that there are more local events recorded at night than during the day for each station. This difference is strongly related to diurnal variation of background noise level for the period range mostly covering the frequency range for the local events. We observed daytime noise level 15 to 20 dB higher than that at the nighttime in high frequencies for almost all stations caused by its proximity to settled areas and roads. Additionally, we observed a splitting peak within the Double Frequency (DF) microseism band; it showed a clear noise increase around the short period DF band at all the stations, decreasing inland. This peak may be related to sea waves locally generated in the Aegean Sea. We also identified a prominent increase related to marble saw companies in some stations' noise PDFs.

  10. Preparation of Ultracold Atom Clouds at the Shot Noise Level

    DEFF Research Database (Denmark)

    Gajdacz, M.; Hilliard, A. J.; Kristensen, Mick

    2016-01-01

    We prepare number stabilized ultracold atom clouds through the real-time analysis of nondestructive images and the application of feedback. In our experiments, the atom number N∼10^6 is determined by high precision Faraday imaging with uncertainty ΔN below the shot noise level, i.e., ΔN... on this measurement, feedback is applied to reduce the atom number to a user-defined target, whereupon a second imaging series probes the number stabilized cloud. By this method, we show that the atom number in ultracold clouds can be prepared below the shot noise level....

  11. Assessment of Work Zone Noise Levels at a Cement Factory in ...

    African Journals Online (AJOL)

    Assessment of Work Zone Noise Levels at a Cement Factory in Tanga, Tanzania. ... measured in most production sections exceeded the allowed limit value of 85 ... Keywords: Noise levels, Noise exposure, Cement factory, Survey, Tanzania ...

  12. Wideband noise observed at ground level in the auroral region

    International Nuclear Information System (INIS)

    Benson, R.F.; Desch, M.D.

    1991-01-01

    A sideband noise event was detected at ground level from the Andoya Rocket Range in Norway in January 1989. The signals were observed on four commercial communication receivers (tuned to 159, 515, 905, and 1200 kHz), an ionosonde (200-kHz to 3.5-MHz interference-free observations) and a riometer (32.5 MHz). The event, which occurred during a period of magnetic disturbance near magnetic midnight, was the only one observed during nearly 3 weeks of operations. This low frequency-of-occurrence is attributed partly to high local noise levels. The ease with which this event was identified on the ionograms produced by the local ionosonde suggests that routine ionosonde recordings should be inspected in search for such events. Such an effort would enhance existing research directed toward developing techniques for identifying quiet communication channels and help to identify the origin and frequency-of-occurrence of high-latitude wideband noise events. 20 refs

  13. Noise levels of a track-laying tractor during field operations in the vineyard

    Directory of Open Access Journals (Sweden)

    Pietro Catania

    2013-09-01

    Full Text Available Noise in agriculture is one of the risk factors to be taken into account in the assessment of the health and safety of workers; in particular, it is known that the tractor is a source of high noise. The Italian Low Decree 81/2008 defined the requirements for assessing and managing noise risk identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This paper concerns the analysis of the noise risk arising from the use of a tracklaying tractor during field operations carried out in the vineyard. The objective of this study was to evaluate the noise level that comes close to the ear of the operator driving the tractor measuring the values of equivalent sound level (Leq(A and peak sound pressure (LCpk. We considered four options related to the same tractor coupled with the following tools to perform some farming operations: rototilling, chisel plough, flail mowers and vibro farmer. We considered three test conditions: T1 in flat (slope 0%, T2 uphill and T3 downhill (both 30% slope. The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. Each survey lasted 2 minutes, with an interval of measurement equal to 0.5 s. The tests were performed in compliance with the standards ISO 9612 and ISO 9432. The results show that the measured sound levels exceed the limits allowed by the regulations in almost all the test conditions; values exceeding the threshold limit of 80 dB(A were recorded coming up to a maximum value of 92.8 dB(A for flail mowers in test T1. When limits imposed by the regulations are exceeded, the operator is obliged to wear the appropriate Personal Protective Equipment.

  14. Effect of external classroom noise on schoolchildren's reading and mathematics performance: correlation of noise levels and gender.

    Science.gov (United States)

    Papanikolaou, M; Skenteris, N; Piperakis, S M

    2015-02-01

    The present study investigated the effect of low, medium, and high traffic road noise as well as irrelevant background speech noise on primary school children's reading and mathematical performance. A total of 676 participants (324 boys, 47.9% and 352 girls, 52.1%) of the 4th and 5th elementary classes participated in the project. The participants were enrolled in public primary schools from urban areas and had ages ranging from 9 to 10 years and from. Schools were selected on the basis of increasing levels of exposure to road traffic noise and then classified into three categories (Low noise: 55-66 dB, Medium noise: 67-77 dB, and High noise: 72-80 dB). We measured reading comprehension and mathematical skills in accordance with the national guidelines for elementary education, using a test designed specifically for the purpose of this study. On the one hand, children in low-level noise schools showed statistically significant differences from children in medium- and high-level noise schools in reading performance (plevel noise schools differed significantly from children in high-level noise schools but only in mathematics performance (p=0.001). Girls in general did better in reading score than boys, especially in schools with medium- and high-level noise. Finally the levels of noise and gender were found to be two independent factors.

  15. modelling traffic noise level on roadside traders at wurukum market

    African Journals Online (AJOL)

    HOD

    . This leads to poor planning and traffic control strategies within the town to reduce ... embark on a study to assess the level of noise pollution .... industrial products such as cement, fuel, timber, water, waste, etc ... used for a manual traffic count.

  16. The Effect of Age and Type of Noise on Speech Perception under Conditions of Changing Context and Noise Levels.

    Science.gov (United States)

    Taitelbaum-Swead, Riki; Fostick, Leah

    2016-01-01

    Everyday life includes fluctuating noise levels, resulting in continuously changing speech intelligibility. The study aims were: (1) to quantify the amount of decrease in age-related speech perception, as a result of increasing noise level, and (2) to test the effect of age on context usage at the word level (smaller amount of contextual cues). A total of 24 young adults (age 20-30 years) and 20 older adults (age 60-75 years) were tested. Meaningful and nonsense one-syllable consonant-vowel-consonant words were presented with the background noise types of speech noise (SpN), babble noise (BN), and white noise (WN), with a signal-to-noise ratio (SNR) of 0 and -5 dB. Older adults had lower accuracy in SNR = 0, with WN being the most difficult condition for all participants. Measuring the change in speech perception when SNR decreased showed a reduction of 18.6-61.5% in intelligibility, with age effect only for BN. Both young and older adults used less phonemic context with WN, as compared to other conditions. Older adults are more affected by an increasing noise level of fluctuating informational noise as compared to steady-state noise. They also use less contextual cues when perceiving monosyllabic words. Further studies should take into consideration that when presenting the stimulus differently (change in noise level, less contextual cues), other perceptual and cognitive processes are involved. © 2016 S. Karger AG, Basel.

  17. [Comfort and noise level in infants with helmet interface].

    Science.gov (United States)

    Medina, A; Alvarez Fernández, P; Rey Galán, C; Álvarez Mendiola, P; Álvarez Blanco, S; Vivanco Allende, A

    2015-10-01

    To evaluate comfort and noise intensity using the COMFORT scale in infants who receive respiratory support with a helmet interface. An observational descriptive study was conducted on all infants (1 to 12 months of age) admitted to a PICU from November 1st 2013 to March 31st 2014 and who received non-invasive ventilation with a helmet interface. Tolerance to the interface was assessed by use of the COMFORT scale. The intensity of the noise to which the infants were exposed was measured with a TES1350A HIBOK 412 sound-level meter. Three measurements were made every day. Twenty seven patients with bronchiolitis (median age: 54 days; range: 10 to 256) were included. Median COMFORT score in the first day was 21 points (14 - 28). An increase in patient comfort was found with a gradual decrease in the scores, with a maximum reduction of 22% from the first hours (score of 22) to the fifth day (score of 18). The minimum sound intensity registered was 42dB, and the maximum was 78dB. Background noise intensity was associated with noise intensity in the helmet. No differences were observed in COMFORT score and noise intensity between ventilator devices. Helmet interface was well tolerated by infants. COMFORT score results are an indicator that infants were comfortable or very comfortable. The measured noise intensity was in the safe range permitted by World Health Organization. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  18. EVALUATION OF THE ENVIRONMENTAL NOISE LEVELS IN ABUJA MUNICIPALITY USING MOBILE PHONES.

    Science.gov (United States)

    Ibekwe, T; Folorunso, D; Ebuta, A; Amodu, J; Nwegbu, M; Mairami, Z; Liman, I; Okebaram, C; Chimdi, C; Durogbola, B; Suleiman, H; Mamven, H; Baamlong, N; Dahilo, E; Gbujie, I; Ibekwe, P; Nwaorgu, O

    2016-12-01

    Noise remains a nuisance which impacts negatively on the physical, social and psychological wellbeing of man. It aggravates chronic illnesses like hypertension and other cardiopulmonary diseases. Unfortunately, increased activities from industrialization and technological transfers/drifts have tumultuously led to increased noise pollution in most of our fast growing cities today and hence the need for concerted efforts in monitoring and regulating our environmental noise. To assess the equivalent noise level (Leq) in Abuja municipality and promote a simple method for regular assessment of Leq within our environment. This is a cross-sectional community based study of the environmental Leq of Abuja municipality conducted between January 2014 and January 2016. The city was divided into 12 segments including residential, business and market areas via the Abuja Geographic Information System. The major markets were captured separately on a different scale. Measurements were taken with the mobile phone softwares having validated this with Extech 407730 digital sound level meter, serial no Z310135 . Leq(A) were measured at different points and hours of the day and night. The average Leq(A) were classified according to localities and compared with WHO standard safety levels. LeqD ranged 71-92dB(A); 42-79dB(A) and 69-90dB(A) in business/ parks, residential and market places respectively. The Night measurements were similar 18dB(A)-56dB(A) and the day-night Leq(A)=77.2dB(A) and 90.4dB(A) for residential and business zones. The night noise levels are satisfactory but the day and day-night levels are above the recommended tolerable values by WHO and therefore urgently call for awareness and legislative regulations.

  19. Photonic microwave signals with zeptosecond-level absolute timing noise

    Science.gov (United States)

    Xie, Xiaopeng; Bouchand, Romain; Nicolodi, Daniele; Giunta, Michele; Hänsel, Wolfgang; Lezius, Matthias; Joshi, Abhay; Datta, Shubhashish; Alexandre, Christophe; Lours, Michel; Tremblin, Pierre-Alain; Santarelli, Giorgio; Holzwarth, Ronald; Le Coq, Yann

    2017-01-01

    Photonic synthesis of radiofrequency (RF) waveforms revived the quest for unrivalled microwave purity because of its ability to convey the benefits of optics to the microwave world. In this work, we perform a high-fidelity transfer of frequency stability between an optical reference and a microwave signal via a low-noise fibre-based frequency comb and cutting-edge photodetection techniques. We demonstrate the generation of the purest microwave signal with a fractional frequency stability below 6.5 × 10-16 at 1 s and a timing noise floor below 41 zs Hz-1/2 (phase noise below -173 dBc Hz-1 for a 12 GHz carrier). This outperforms existing sources and promises a new era for state-of-the-art microwave generation. The characterization is achieved through a heterodyne cross-correlation scheme with the lowermost detection noise. This unprecedented level of purity can impact domains such as radar systems, telecommunications and time-frequency metrology. The measurement methods developed here can benefit the characterization of a broad range of signals.

  20. Equivalent threshold sound pressure levels (ETSPL) for Interacoustics DD 45 supra-aural audiometric earphones

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2010-01-01

    This paper describes the determination and results of pure tone Equivalent Threshold Sound Pressure Levels for the Interacoustics DD45 audiometric earphone equipped with standard Model 51 cushions. The size and shape of the DD45 transducer resembles the classical Telephonics TDH 39 earphone. Pure...... tone hearing threshold measurements were performed for both ears of 29 test subjects. All audiometric frequencies from 125 Hz to 8 kHz were used. The data are intended for inclusion in future standardized Reference Equivalent Threshold Sound Pressure Levels. The results show that the DD45 may be a good...

  1. Noise exposure levels for musicians during rehearsal and performance times.

    Science.gov (United States)

    McIlvaine, Devon; Stewart, Michael; Anderson, Robert

    2012-03-01

    The purpose of this study was to determine daily noise doses and 8-hour time weighted averages for rock band musicians, crew members, and spectators during a typical rehearsal and performance using both Occupational Safety and Health Administration (OSHA) and National Institute of Occupational Safety and Health (NIOSH) measurement criteria. Personal noise dosimetry was completed on five members of a rock band during one 2-hr rehearsal and one 4-hr performance. Time-weighted averages (TWA) and daily dose values were calculated using both OSHA and NIOSH criteria and compared to industry guidelines for enrollment in hearing conservation programs and the use of hearing protection devices. TWA values ranged from 84.3 to 90.4 dBA (OSHA) and from 90.0 to 96.4 dBA (NIOSH) during the rehearsal. The same values ranged from 91.0 to 99.7 dBA (OSHA) and 94.0 to 102.8 dBA (NIOSH) for the performance. During the rehearsal, daily noise doses ranged from 45.54% to 106.7% (OSHA) and from 317.74% to 1396.07% (NIOSH). During the performance, doses ranged from 114.66% to 382.49% (OSHA) and from 793.31% to 5970.15% (NIOSH). The musicians in this study were exposed to dangerously high levels of noise and should be enrolled in a hearing conservation programs. Hearing protection devices should be worn, especially during performances. The OSHA measurement criteria yielded values significantly more conservative than those produced by NIOSH criteria. Audiologists should counsel musician-patients about the hazards of excessive noise (music) exposure and how to protect their hearing.

  2. Measurement of Acceptable Noise Level with Background Music.

    Science.gov (United States)

    Ahn, Hyun-Jung; Bahng, Junghwa; Lee, Jae Hee

    2015-09-01

    Acceptable noise level (ANL) is a measure of the maximum background noise level (BNL) that a person is willing to tolerate while following a target story. Although researchers have used various sources of target sound in ANL measures, a limited type of background noise has been used. Extending the previous study of Gordon-Hickey & Moore (2007), the current study determined the effect of music genre and tempo on ANLs as possible factors affecting ANLs. We also investigated the relationships between individual ANLs and the familiarity of music samples and between music ANLs and subjective preference. Forty-one participants were seperated into two groups according to their ANLs, 29 low-ANL listeners and 12 high-ANL listeners. Using Korean ANL material, the individual ANLs were measured based on the listeners' most comfortable listening level and BNL. The ANLs were measured in six conditions, with different music tempo (fast, slow) and genre (K-pop, pop, classical) in a counterbalanced order. Overall, ANLs did not differ by the tempo of background music, but music genre significantly affected individual ANLs. We observed relatively higher ANLs with K-pop music and relatively lower ANLs with classical music. This tendency was similar in both low-ANL and high-ANL groups. However, the subjective ratings of music familiarity and preference affected ANLs differently for low-ANL and high-ANL groups. In contrast to the low-ANL listeners, the ANLs of the high-ANL listeners were significantly affected by music familiarity and preference. The genre of background music affected ANLs obtained using background music. The degree of music familiarity and preference appears to be associated with individual susceptibility to background music only for listeners who are greatly annoyed by background noise (high-ANL listeners).

  3. Evaluation of noise level at intensive care units in selected hospitals of Sanandaj

    Directory of Open Access Journals (Sweden)

    Nammam Ali Azadi

    2015-08-01

    Conclusion: We found the noise levels were always above the EPA thresholds at all three hospitals both during the day and night. It is recommended to train hospital officials and staffs for keeping noise levels to an acceptable level.

  4. Enhancing the management of the noise level using six sigma method: a case study on the machining industry

    Science.gov (United States)

    Rimantho, D.; Hanantya, M. W.

    2017-12-01

    The hearing disorder is caused by noises in the workplace, it has been a concern for numerous researchers. This study aims to improve the performance of the management of the noise level by applying the six sigma method. Data collection is done directly by using a sound level meter. In addition, several key informants also used in order to gather information related to the problem. The results showed the values of Cp and Cpk on the entire department are still below the recommended value. Moreover, the results also showed the potential failure (DPMO) approximately 115,260.6 and equivalent to the Sigma value is approximately 2.70. Furthermore, the highest value of the RPN in FMEA analysis is the workers not wear factor of earplug which is about 56. Thus, it is necessary to make enhancements to the process of managing the noise level in the framework of continuous improvement.

  5. Temporary threshold shifts from exposures to equal equivalent continuous A-weighted sound pressure level

    DEFF Research Database (Denmark)

    Ordoñez, Rodrigo Pizarro; Hammershøi, Dorte

    2014-01-01

    the assumptions made using the A-weighting curve for the assessment of hearing damage. By modifying exposure ratings to compensate for the build-up of energy at mid and high-frequencies (above 1 kHz) due to the presence of the listener in the sound field and for the levels below an effect threshold that does...... not induce changes in hearing (equivalent quiet levels), ratings of the sound exposure that reflect the observed temporary changes in auditory function can be obtained.......According to existing methods for the assessment of hearing damage, signals with the same A-weighted equivalent level should pose the same hazard to the auditory system. As a measure of hazard, it is assumed that Temporary Thresholds Shifts (TTS) reflect the onset of alterations to the hearing...

  6. Are the noise levels acceptable in a built environment like Hong Kong?

    Science.gov (United States)

    To, Wai Ming; Mak, Cheuk Ming; Chung, Wai Leung

    2015-01-01

    Governments all over the world have enacted environmental noise directives and noise control ordinances/acts to protect tranquility in residential areas. However, there is a lack of literature on the evaluation of whether the Acceptable Noise Levels (ANLs) stipulated in the directive/ordinance/act are actually achievable. The study aimed at measuring outdoor environmental noise levels in Hong Kong and identifying whether the measured noise levels are lower than the stipulated ANLs at 20 categories of residential areas. Data were gathered from a territory-wide noise survey. Outdoor noise measurements were conducted at 203 residential premises in urban areas, low-density residential areas, rural areas, and other areas. In total, 366 daytime hourly Leq outdoor noise levels, 362 nighttime hourly Leq outdoor noise levels, and 20 sets of daily, that is, 24 Leq,1-h outdoor noise levels were recorded. The mean daytime Leq,1-h values ranged 54.4-70.8 dBA, while the mean nighttime Leq,1-h values ranged 52.6-67.9 dBA. When the measured noise levels were compared with the stipulated ANLs, only three out of the 20 categories of areas had outdoor noise levels below ANLs during daytime. All other areas (and all areas during nighttime) were found to have outdoor noise levels at or above ANLs. PMID:26572703

  7. Noise

    Science.gov (United States)

    Noise is all around you, from televisions and radios to lawn mowers and washing machines. Normally, you ... sensitive structures of the inner ear and cause noise-induced hearing loss. More than 30 million Americans ...

  8. The Analysis of Low Noise Protection Barriers Influence on Tram Traffic Noise Levels

    Directory of Open Access Journals (Sweden)

    Ahac Maja

    2013-07-01

    Full Text Available The paper describes the analysis of tram traffic noise situation in residential areas in the vicinity of Drzic Avenue, one of the major routes between the northern and southern part of the Croatian capital city Zagreb, and the effect of low barriers placed by the tracks on tram noise mitigation. In order to evaluate the effect of planned protection measure, noise models were produced and verified with short-term field measurements. Calculations were conducted by means of noise prediction software, using European interim noise prediction method and 3D model of analyzed area. Finally, the results of noise calculations for existing tram traffic situation and planned measure of protection are presented on noise maps.

  9. Noise levels from toys and recreational articles for children and teenagers.

    Science.gov (United States)

    Hellstrom, P A; Dengerink, H A; Axelsson, A

    1992-10-01

    This study examined the noise level emitted by toys and recreational articles used by children and teenagers. The results indicate that many of the items tested emit sufficiently intense noise to be a source of noise induced hearing loss in school-age children. While the baby toys provided noise exposure within the limits of national regulations, they are most intense in a frequency range that corresponds to the resonance frequency of the external auditory canal of very young children. Hobby motors emit noise that may require protection depending upon the length of use. Fire-crackers and cap guns emit impulse noises that exceed even conservative standards for noise exposure.

  10. The effect of equivalence scales on poverty at Oblast level in Ukraine

    Directory of Open Access Journals (Sweden)

    Gianni Betti

    2014-06-01

    Full Text Available This paper aims at properly measuring and evaluating the impact of equivalence scales on poverty and inequality at both national and regional (Oblast level in Ukraine. A new equivalence scale set is proposed and estimated on the basis of the UHLSC data; for some regions the precision of the estimate results as not being sufficient due to small sub-sample sizes. A variant of EBLUP small area estimation technique is proposed and implemented to estimate poverty measures properly and to reduce standard errors of such estimates; the variant concerned is based on a ratio approach: in this way the effect of the difficult-to-qualify institutional and historical factors, common to the country and its regions, is abstracted.

  11. Assessment of ambient noise levels in the intensive care unit of a university hospital

    Directory of Open Access Journals (Sweden)

    Hatem O Qutub

    2009-01-01

    Conclusion : Some sources of environmental noise, such as the use of oxygen, suction equipment or respirators are unavoidable. Nevertheless, hospital ICUs should have measures to minimize the level of exposure to noise in the ICU. Further research in this area might focus on the noise level and other modifiable environmental stress factors in the ICU that affect patients as well as the staff.

  12. Noise sensitivity, rather than noise level, predicts the non-auditory effects of noise in community samples: a population-based survey

    Directory of Open Access Journals (Sweden)

    Jangho Park

    2017-04-01

    Full Text Available Abstract Background Excessive noise affects human health and interferes with daily activities. Although environmental noise may not directly cause mental illness, it may accelerate and intensify the development of latent mental disorders. Noise sensitivity (NS is considered a moderator of non-auditory noise effects. In the present study, we aimed to assess whether NS is associated with non-auditory effects. Methods We recruited a community sample of 1836 residents residing in Ulsan and Seoul, South Korea. From July to November 2015, participants were interviewed regarding their demographic characteristics, socioeconomic status, medical history, and NS. The non-auditory effects of noise were assessed using the Center of Epidemiologic Studies Depression, Insomnia Severity index, State Trait Anxiety Inventory state subscale, and Stress Response Inventory-Modified Form. Individual noise levels were recorded from noise maps. A three-model multivariate logistic regression analysis was performed to identify factors that might affect psychiatric illnesses. Results Participants ranged in age from 19 to 91 years (mean: 47.0 ± 16.1 years, and 37.9% (n = 696 were male. Participants with high NS were more likely to have been diagnosed with diabetes and hyperlipidemia and to use psychiatric medication. The multivariable analysis indicated that even after adjusting for noise-related variables, sociodemographic factors, medical illness, and duration of residence, subjects in the high NS group were more than 2 times more likely to experience depression and insomnia and 1.9 times more likely to have anxiety, compared with those in the low NS group. Noise exposure level was not identified as an explanatory value. Conclusions NS increases the susceptibility and hence moderates there actions of individuals to noise. NS, rather than noise itself, is associated with an elevated susceptibility to non-auditory effects.

  13. Potential of neuro-fuzzy methodology to estimate noise level of wind turbines

    Science.gov (United States)

    Nikolić, Vlastimir; Petković, Dalibor; Por, Lip Yee; Shamshirband, Shahaboddin; Zamani, Mazdak; Ćojbašić, Žarko; Motamedi, Shervin

    2016-01-01

    Wind turbines noise effect became large problem because of increasing of wind farms numbers since renewable energy becomes the most influential energy sources. However, wind turbine noise generation and propagation is not understandable in all aspects. Mechanical noise of wind turbines can be ignored since aerodynamic noise of wind turbine blades is the main source of the noise generation. Numerical simulations of the noise effects of the wind turbine can be very challenging task. Therefore in this article soft computing method is used to evaluate noise level of wind turbines. The main goal of the study is to estimate wind turbine noise in regard of wind speed at different heights and for different sound frequency. Adaptive neuro-fuzzy inference system (ANFIS) is used to estimate the wind turbine noise levels.

  14. Effects of self-reported sensitivity and road-traffic noise levels on the immune system.

    Directory of Open Access Journals (Sweden)

    Ahra Kim

    Full Text Available Sensitivity to noise, particularly road traffic noise, can increase cortisol levels and result in changes in immune system biomarkers. Therefore, continuous exposure to noise can have an effect on immune function, hormonal levels, and cardiovascular function, leading to hypertension and stress. The purpose of this study was to investigate the changes in stress-and immune system-related biomarkers according to the self-reported sensitivity to noise and exposure to road traffic noise, to ultimately determine the potential effects of noise on health. A survey was conducted through questionnaire (ISO/TS 15666 sent to 172 female subjects in Korea, including 128 from Ulsan and 44 from Seoul. The average noise level was calculated, and blood samples were collected for measurements of cortisol levels, Natural killer (NK / Natural killer T (NKT cell populations, and NK cell activity (through measurements of interleukin-12 (IL-12 and interferon-gamma (INF-γ concentrations. Multivariate linear regression analysis of the measured biomarkers according to the road traffic noise level and self-reported noise sensitivity was conducted adjusting for the effects of age, alcohol status, smoking status, regular exercise, and residence period. IL-12 levels increased, whereas the NKT cell population decreased with increasing noise levels. The results further suggested that cortisol levels are more influenced by the subject's sensitivity to noise than to the level of chronic road traffic noise. Therefore, noise appears to have the largest effect on IL-12 levels as well as the population and activity of NKT cells. In conclusion, our results suggest that low-level road traffic noise and sensitivity to noise can affect health by causing changes in the immune response through mechanisms other than increased cortisol.

  15. Projected contributions of future wind farm development to community noise and annoyance levels in Ontario, Canada

    International Nuclear Information System (INIS)

    Whitfield Aslund, Melissa L.; Ollson, Christopher A.; Knopper, Loren D.

    2013-01-01

    Wind turbines produce sound during their operation; therefore, jurisdictions around the world have developed regulations regarding the placement of electricity generating wind farms with the intent of preventing unacceptable levels of ‘community noise’ in their vicinity. However, as survey results indicate that the relationship between wind turbine noise and annoyance may differ from noise-annoyance relationships for other common noise sources (e.g., rail, traffic), there are concerns that the application of general noise guidelines for wind turbines may lead to unacceptably high levels of annoyance in communities. In this study, previously published survey results that quantified wind turbine noise and self-reported annoyance were applied to the predicted noise levels (from turbines and transformers) for over 8000 receptors in the vicinity of 13 planned wind power developments in the province of Ontario, Canada. The results of this analysis indicate that the current wind turbine noise restrictions in Ontario will limit community exposure to wind turbine related noise such that levels of annoyance are unlikely to exceed previously established background levels of noise-related annoyance from other common noise sources. This provides valuable context that should be considered by policy-makers when evaluating the potential impacts of wind turbine noise on the community. -- highlights: •Wind turbine noise-annoyance relationship used to predict annoyance in Ontario. •Noise annoyance predicted to be <8% for non-participants <1 km from turbines. •Predicted levels of wind turbine noise annoyance similar to that from traffic noise. •Wind turbine noise annoyance not expected to exceed existing background levels

  16. Anthropogenic noise alters bat activity levels and echolocation calls

    OpenAIRE

    Bunkley, Jessie P.; McClure, Christopher J.W.; Kleist, Nathan J.; Francis, Clinton D.; Barber, Jesse R.

    2015-01-01

    Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband nois...

  17. Evaluation of noise levels in manufacturing sectors in Thika district ...

    African Journals Online (AJOL)

    Noise is considered as any unwanted sound that may adversely affect the health and wellbeing of individuals or populations exposed. This study assessed the magnitude of occupational noise exposures to workers in different manufacturing sectors in Thika District‐Kenya. Systematic random sampling was used to select 8 ...

  18. A study investigating sound sources and noise levels in neonatal ...

    African Journals Online (AJOL)

    Background. Exposure to noise in the neonatal intensive care unit (NICU) has the potential to affect neonatal auditory development, sleep patterns and physiological stability, thus impacting on developmental progress. Objectives. This study aimed to identify noise sources in three NICUs in Johannesburg, South Africa, and ...

  19. Variations in the microseismic noise level observed at the Bucovina Seismic Array (BURAR)

    International Nuclear Information System (INIS)

    Ghica, Daniela; Radulian, Mircea; Popa, Mihaela

    2005-01-01

    The microseismic noise level analysis for a seismic array is an essential step to accurately process the data recorded by the system. Basically, the observed background noise is a complex combination of natural and cultural sources as local geology, specific area activity (roads traffic, agricultural and industrial activities) or weather conditions.The understanding of the BURAR site noise characteristics is important for the array specific techniques (beamforming, f-k analysis), to apply the correct bandpass filtering, in order to obtain noise suppression and conservation of the 'true' seismic signal. The array monitoring potential of very small earthquakes and explosions will be enhanced, based on the best signal-to-noise ratio.The noise study at BURAR was carried out over one-year period, considering the noise power spectra in a 0.1 to 10 Hz frequency interval, for every 24 hours: 5 minutes during day and 5 minutes during night. Only short-period vertical sensors were considered. Systematic variations in the microseismic noise level at the BURAR site were observed:- diurnal: a decreasing of about 40% in night noise level at 1 Hz frequency; at 6 Hz frequency, the decreasing could reach 80-90% for 'non-winter' months (May to October); - seasonal: during the winter time, a lower noise level is observed, due to the restraining of the local specific activity (especially agriculture and farming) and of the road traffic. To summarize the level of microseismic noise observed at BURAR for one-year observations, a model curve for array noise level has been estimated, including upper and lower bounds of noise power density together with average spectrum. The BURAR noise model will be useful in the process of local site conditions estimation, by eliminating the noise contribution from the array recording. Also, the detection processing, phase identification and events location procedures will be significantly improved. (authors)

  20. Fast noise level estimation algorithm based on principal component analysis transform and nonlinear rectification

    Science.gov (United States)

    Xu, Shaoping; Zeng, Xiaoxia; Jiang, Yinnan; Tang, Yiling

    2018-01-01

    We proposed a noniterative principal component analysis (PCA)-based noise level estimation (NLE) algorithm that addresses the problem of estimating the noise level with a two-step scheme. First, we randomly extracted a number of raw patches from a given noisy image and took the smallest eigenvalue of the covariance matrix of the raw patches as the preliminary estimation of the noise level. Next, the final estimation was directly obtained with a nonlinear mapping (rectification) function that was trained on some representative noisy images corrupted with different known noise levels. Compared with the state-of-art NLE algorithms, the experiment results show that the proposed NLE algorithm can reliably infer the noise level and has robust performance over a wide range of image contents and noise levels, showing a good compromise between speed and accuracy in general.

  1. Industrial noise level study in a wheat processing factory in ilorin, nigeria

    Science.gov (United States)

    Ibrahim, I.; Ajao, K. R.; Aremu, S. A.

    2016-05-01

    An industrial process such as wheat processing generates significant noise which can cause adverse effects on workers and the general public. This study assessed the noise level at a wheat processing mill in Ilorin, Nigeria. A portable digital sound level meter HD600 manufactured by Extech Inc., USA was used to determine the noise level around various machines, sections and offices in the factory at pre-determined distances. Subjective assessment was also mode using a World Health Organization (WHO) standard questionnaire to obtain information regarding noise ratings, effect of noise on personnel and noise preventive measures. The result of the study shows that the highest noise of 99.4 dBA was recorded at a pressure blower when compared to other machines. WHO Class-4 hearing protector is recommended for workers on the shop floor and room acoustics should be upgraded to absorb some sounds transmitted to offices.

  2. Evaluation of noise level in architecture department building in University of Sumatera Utara

    Science.gov (United States)

    Amran, Novrial; Damanik, Novita Hillary Christy

    2018-03-01

    Noise is one the comfort factors that need to be noticed, particularly in an educational environment. Hearing a high noise in a period can affect students’ learning performance. The aims of this study were to know the noise level and get an appropriate design to reduce noise in Architecture Department building in the University of Sumatera Utara, considering that architecture students often spend most of their time inside the room. The measurement was conducted in four rooms for two days each from 09:00 – 12:00 and from 13:00 – 16:00 by using Sound Level Meter that placed near the noise source of the room. The result indicated that the average of noise level exceeded the 55 dB(A) so it still needs the appropriate design to reduce the noise that occurs in the building.

  3. ASSESSMENT OF WORK ZONE NOISE LEVELS AT A CEMENT ...

    African Journals Online (AJOL)

    Osondu

    2012-03-24

    Mar 24, 2012 ... in various production sections at a cement factory in Tanga, Tanzania and assess attitudes of ... Ethiopian Journal of Environmental Studies and Management EJESM Vol. 5 No ..... exposure, Handbook of Noise Control, Harris,.

  4. A study investigating sound sources and noise levels in neonatal

    African Journals Online (AJOL)

    in Asia and sub-Saharan Africa accounting for 60% ... to identify and evaluate environmental stressors in the NICU, and to ... The findings have important implications for neonatal care, and highlight the importance of noise reduction and ...

  5. Atmospheric polychlorinated biphenyls in Indian cities: Levels, emission sources and toxicity equivalents

    International Nuclear Information System (INIS)

    Chakraborty, Paromita; Zhang, Gan; Eckhardt, Sabine; Li, Jun; Breivik, Knut; Lam, Paul K.S.; Tanabe, Shinsuke; Jones, Kevin C.

    2013-01-01

    Atmospheric concentration of Polychlorinated biphenyls (PCBs) were measured on diurnal basis by active air sampling during Dec 2006 to Feb 2007 in seven major cities from the northern (New Delhi and Agra), eastern (Kolkata), western (Mumbai and Goa) and southern (Chennai and Bangalore) parts of India. Average concentration of Σ 25 PCBs in the Indian atmosphere was 4460 (±2200) pg/m −3 with a dominance of congeners with 4–7 chlorine atoms. Model results (HYSPLIT, FLEXPART) indicate that the source areas are likely confined to local or regional proximity. Results from the FLEXPART model show that existing emission inventories cannot explain the high concentrations observed for PCB-28. Electronic waste, ship breaking activities and dumped solid waste are attributed as the possible sources of PCBs in India. Σ 25 PCB concentrations for each city showed significant linear correlation with Toxicity equivalence (TEQ) and Neurotoxic equivalence (NEQ) values. Highlights: •Unlike decreasing trend of PCBs in United States and European countries, high levels of PCBs remain in the Indian atmosphere. •Existing emission inventories cannot explain the high PCB concentrations in Indian atmosphere. •Electronic waste recycling, ship dismantling and open burning of municipal solid waste are implicated as potential sources. -- Measurement of atmospheric Polychlorinated biphenyls in seven major Indian cities

  6. I'm trying to heal...noise levels in a pediatric intensive care unit.

    Science.gov (United States)

    Milette, Isabelle H; Carnevale, Franco A

    2003-01-01

    The literature demonstrates clearly that most intensive care units exceed the standard recommendations for noise levels in hospitals, and that high noise levels have negative impacts on patients and staff. The purpose of this study was to evaluate the level of noise in a PICU and compare it to the recommendations of international bodies. We outline recommendations to promote the awareness of this problem and suggest strategies to decrease the level of noise in a PICU. The orientations of these strategies are threefold: 1) architectural-acoustic design, 2) equipment design and, most importantly, 3) staff education.

  7. Boltzmann-distribution-equivalent for Lévy noise and how it leads to thermodynamically consistent epicatalysis

    Science.gov (United States)

    Bier, Martin

    2018-02-01

    Nonequilibrium systems commonly exhibit Lévy noise. This means that the distribution for the size of the Brownian fluctuations has a "fat" power-law tail. Large Brownian kicks are then more common as compared to the ordinary Gaussian distribution. We consider a two-state system, i.e., two wells and a barrier in between. The barrier is sufficiently high for a barrier crossing to be a rare event. When the noise is Lévy, we do not get a Boltzmann distribution between the two wells. Instead we get a situation where the distribution between the two wells also depends on the height of the barrier that is in between. Ordinarily, a catalyst, by lowering the barrier between two states, speeds up the relaxation to an equilibrium, but does not change the equilibrium distribution. In an environment with Lévy noise, on the other hand, we have the possibility of epicatalysis, i.e., a catalyst effectively altering the distribution between two states through the changing of the barrier height. After deriving formulas to quantitatively describe this effect, we discuss how this idea may apply in nuclear reactors and in the biochemistry of a living cell.

  8. Traffic background level and signal duration effects on aircraft noise judgment

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, G W; Haasz, A A

    1977-04-22

    The effects of background traffic noise level and signal duration on perceived aircraft noise levels during a flyover event are investigated. Tapes of traffic noise at different levels on which aircraft flyover noise events of different durations were superimposed were played to groups of observers in a room simulating indoor conditions. It is found that the presence of steady background traffic noise reduces the perceived noisiness of aircraft flyovers provided that the duration of the flyover event is sufficiently short in relation to flyover time. For a given event level, a reduction of 21 dB(A) in background noise level leads to the perception of a 5.5 dB(A) increase in peak event level. Regressions of observer response with the noise pollution index show a lower correlation than those with variables based on background noise level and peak signal level, although the data are found to exhibit a number of significant trends associated with noise pollution index variations.

  9. Noise-level determination for discrete spectra with Gaussian or Lorentzian probability density functions

    International Nuclear Information System (INIS)

    Moriya, Netzer

    2010-01-01

    A method, based on binomial filtering, to estimate the noise level of an arbitrary, smoothed pure signal, contaminated with an additive, uncorrelated noise component is presented. If the noise characteristics of the experimental spectrum are known, as for instance the type of the corresponding probability density function (e.g., Gaussian), the noise properties can be extracted. In such cases, both the noise level, as may arbitrarily be defined, and a simulated white noise component can be generated, such that the simulated noise component is statistically indistinguishable from the true noise component present in the original signal. In this paper we present a detailed analysis of the noise level extraction when the additive noise is Gaussian or Lorentzian. We show that the statistical parameters in these cases (mainly the variance and the half width at half maximum, respectively) can directly be obtained from the experimental spectrum even when the pure signal is erratic. Further discussion is given for cases where the noise probability density function is initially unknown.

  10. Analysis of noise pollution level in a University campus in South India

    Science.gov (United States)

    Thattai, D.; Sudarsan, J. S.; Sathyanathan, R.; Ramasamy, Visalatchi

    2017-07-01

    Noise comprises those sounds occurring around us that are not part of the environment under consideration. Noise is also a type of pollution and impacts on our health and wellness. The prevalence of noise is increasing in magnitude and severity because of growing population and urbanization. Noise pollution leads to many chronic and socially significant impacts. This study analyzes the level of noise at different points in SRM University. As the University encompasses a hospital also, it is more important to identify the sources of high noise levels and control them. As per Indian standards the desirable noise pollution for educational institutions and hospitals in daytime is 50 dbA. Noise levels were measured with a sound level meter at 19 points within the campus at three different timings (8-10 am, 12-2 pm, and 3-5 pm) over two cycles of measurements. The preliminary results show higher noise levels during morning and evening. Noise during Cycle 2 (latter half of semester) was 20% more compared to that of Cycle 1 (beginning of semester).

  11. Methods For an Acceptable Traffic Noise Level Design

    Directory of Open Access Journals (Sweden)

    Zlatko Sviben

    2004-07-01

    Full Text Available Road noise disturbance on rough roads by means of loudnesssensor caused by wideband signal components with a significantimpact of tonal effects on smooth roads and in specificactions in driving lead to the annoyance of drivers. A systemicapproach has been applied for the sound quality estimation ofphysical properties of various noise sources and structuralvibroacoustic car properties and its components as an integratedparameter in car design for the purpose of the developmentand vehicle noise reduction. Simulation of the most importantcharacteristics of listening impressions was performedby modem systems of signal analysis together with the presentationof loudness, sharpness, and roughness as essential quantities.Optimization of the noise control measuring regarding vehiclesound was obtained by means of a simulation system withthe capability of the real time original sound filtering. Structuralanalysis was performed as an acoustic modal analysis on therear part and the car interior with the quantitative analysis ofsport and luxury car sounds. The possibility of active noise controlwas studied and examples are given for an application ofpsychoacoustic tools for car sound quality design. Sound qualitywas obtained by an observation of certain aspects, which areempirically or theoretically connected with the design. An experimentalsound synthesis with psychometrical measuring wasapplied. The sound quality of car interior is presented takinginto consideration the criteria of objectivity, reliability and validity.

  12. Detection System of Sound Noise Level (SNL) Based on Condenser Microphone Sensor

    Science.gov (United States)

    Rajagukguk, Juniastel; Eka Sari, Nurdieni

    2018-03-01

    The research aims to know the noise level by using the Arduino Uno as data processing input from sensors and called as Sound Noise Level (SNL). The working principle of the instrument is as noise detector with the show notifications the noise level on the LCD indicator and in the audiovisual form. Noise detection using the sensor is a condenser microphone and LM 567 as IC op-amps, which are assembled so that it can detect the noise, which sounds are captured by the sensor will turn the tide of sinusoida voice became sine wave energy electricity (altering sinusoida electric current) that is able to responded to complaints by the Arduino Uno. The tool is equipped with a detector consists of a set indicator LED and sound well as the notification from the text on LCD 16*2. Work setting indicators on the condition that, if the measured noise > 75 dB then sound will beep, the red LED will light up indicating the status of the danger. If the measured value on the LCD is higher than 56 dB, sound indicator will be beep and yellow LED will be on indicating noisy. If the noise measured value <55 dB, sound indicator will be quiet indicating peaceful from noisy. From the result of the research can be explained that the SNL is capable to detecting and displaying noise level with a measuring range 50-100 dB and capable to delivering the notification noise in audiovisual.

  13. Noise levels of neonatal high-flow nasal cannula devices--an in-vitro study.

    Science.gov (United States)

    König, Kai; Stock, Ellen L; Jarvis, Melanie

    2013-01-01

    Excessive ambient noise levels have been identified as a potential risk factor for adverse outcome in very preterm infants. Noise level measurements for continuous positive airway pressure (CPAP) devices demonstrated that these constantly exceed current recommendations. The use of high-flow nasal cannula (HFNC) as an alternative non-invasive ventilation modality has become more popular in recent years in neonatal care. To study noise levels of two HFNC devices commonly used in newborns. As a comparison, noise levels of a continuous flow CPAP device were also studied. In-vitro study. The noise levels of two contemporary HFNC devices (Fisher & Paykel NHF™ and Vapotherm Precision Flow®) and one CPAP device (Dräger Babylog® 8000 plus) were measured in the oral cavity of a newborn manikin in an incubator in a quiet environment. HFNC flows of 4-8 l/min and CPAP pressures of 4-8 cm H2O were applied. The CPAP flow was set at 8 l/min as per unit practice. Vapotherm HFNC generated the highest noise levels, measuring 81.2-91.4 dB(A) with increasing flow. Fisher & Paykel HFNC noise levels were between 78.8 and 81.2 dB(A). The CPAP device generated the lowest noise levels between 73.9 and 77.4 dB(A). Both HFNC devices generated higher noise levels than the CPAP device. All noise levels were far above current recommendations of the American Academy of Pediatrics. In light of the long duration of non-invasive respiratory support of very preterm infants, less noisy devices are required to prevent the potentially adverse effects of continuing excessive noise exposure in the neonatal intensive care unit. Copyright © 2013 S. Karger AG, Basel.

  14. A noise level prediction method based on electro-mechanical frequency response function for capacitors.

    Science.gov (United States)

    Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

    2013-01-01

    The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective.

  15. Study on traffic noise level of Sylhet by multiple regression analysis associated with health hazards

    Directory of Open Access Journals (Sweden)

    J. B. Alam, M. Jobair Bin Alam, M. M. Rahman, A. K. Dikshit, S. K. Khan

    Full Text Available The study reports the level of traffic-induced noise pollution in Sylhet City. For this purpose noise levels have been measured at thirty-seven major locations of the city from 7 am to 11 pm during the working days. It was observed that at all the locations the level of noise remains far above the acceptable limit for all the time. The noise level on the main road near residential area, hospital area and educational area were above the recommended level (65dBA. It was found that the predictive equations are in 60-70% correlated with the measured noise level. The study suggests that vulnerable institutions like school and hospital should be located about 60m away from the roadside unless any special arrangement to alleviate sound is used.

  16. Ambient and at-the-ear occupational noise exposure and serum lipid levels

    DEFF Research Database (Denmark)

    Arlien-Søborg, Mai C; Schmedes, Astrid S; Stokholm, Z A

    2016-01-01

    -the-ear occupational noise exposure and serum levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides when accounting for well-established predictors of lipid levels. METHODS: This cross-sectional study included 424 industrial workers and 84 financial......OBJECTIVES: Occupational and residential noise exposure has been related to increased risk of cardiovascular disease. Alteration of serum lipid levels has been proposed as a possible causal pathway. The objective of this study was to investigate the relation between ambient and at...... workers to obtain contrast in noise exposure levels. They provided a serum sample and wore portable dosimeters that every 5-s recorded ambient noise exposure levels during a 24-h period. We extracted measurements obtained during work and calculated the full-shift mean ambient noise level. For 331 workers...

  17. Reduction of Classroom Noise Levels Using Group Contingencies

    Science.gov (United States)

    Ring, Brandon M.; Sigurdsson, Sigurdur O.; Eubanks, Sean L.; Silverman, Kenneth

    2014-01-01

    The therapeutic workplace is an employment-based abstinence reinforcement intervention for unemployed drug users where trainees receive on-the-job employment skills training in a classroom setting. The study is an extension of prior therapeutic workplace research, which suggested that trainees frequently violated noise standards. Participants…

  18. Successful mitigation of noise level in laser workshop in RRCAT

    International Nuclear Information System (INIS)

    Kameshwar Rao, A.; Jalali, S.M.; Jain, P.C.; Farkya, S.; Mirza, Z.B.

    2009-01-01

    Overlooking a few exceptional events like earthquakes, hurricanes, storms, avalanches, waterfalls etc, the, nature is by and large silent. In the nineteenth century, with the invention of the machine, noise was born and was tolerated as necessary evil of progress. (author)

  19. Estimating the level of dynamical noise in time series by using fractal dimensions

    International Nuclear Information System (INIS)

    Sase, Takumi; Ramírez, Jonatán Peña; Kitajo, Keiichi; Aihara, Kazuyuki; Hirata, Yoshito

    2016-01-01

    We present a method for estimating the dynamical noise level of a ‘short’ time series even if the dynamical system is unknown. The proposed method estimates the level of dynamical noise by calculating the fractal dimensions of the time series. Additionally, the method is applied to EEG data to demonstrate its possible effectiveness as an indicator of temporal changes in the level of dynamical noise. - Highlights: • A dynamical noise level estimator for time series is proposed. • The estimator does not need any information about the dynamics generating the time series. • The estimator is based on a novel definition of time series dimension (TSD). • It is demonstrated that there exists a monotonic relationship between the • TSD and the level of dynamical noise. • We apply the proposed method to human electroencephalographic data.

  20. Estimating the level of dynamical noise in time series by using fractal dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Sase, Takumi, E-mail: sase@sat.t.u-tokyo.ac.jp [Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 153-8505 (Japan); Ramírez, Jonatán Peña [CONACYT Research Fellow, Center for Scientific Research and Higher Education at Ensenada (CICESE), Carretera Ensenada-Tijuana No. 3918, Zona Playitas, C.P. 22860, Ensenada, Baja California (Mexico); Kitajo, Keiichi [BSI-Toyota Collaboration Center, RIKEN Brain Science Institute, Wako, Saitama 351-0198 (Japan); Aihara, Kazuyuki; Hirata, Yoshito [Graduate School of Information Science and Technology, The University of Tokyo, Tokyo 153-8505 (Japan); Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505 (Japan)

    2016-03-11

    We present a method for estimating the dynamical noise level of a ‘short’ time series even if the dynamical system is unknown. The proposed method estimates the level of dynamical noise by calculating the fractal dimensions of the time series. Additionally, the method is applied to EEG data to demonstrate its possible effectiveness as an indicator of temporal changes in the level of dynamical noise. - Highlights: • A dynamical noise level estimator for time series is proposed. • The estimator does not need any information about the dynamics generating the time series. • The estimator is based on a novel definition of time series dimension (TSD). • It is demonstrated that there exists a monotonic relationship between the • TSD and the level of dynamical noise. • We apply the proposed method to human electroencephalographic data.

  1. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools.

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M; Oskarsson, Gudmundur Kr; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called "Hjalli model", and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the "Hjalli model") experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the "Hjalli model" preschool and fewer "Hjalli model" teachers reported voice symptoms. Public preschool teachers experienced more stress than "Hjalli model" teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences.

  2. A preliminary assessment of noise level during Deepawali festival in Balasore, India.

    Science.gov (United States)

    Goswami, Shreerup; Swain, Bijay Kumar; Mohapatra, Hara Prasad; Bal, Kshirod Kumar

    2013-11-01

    A preliminary assessment of noise levels during Deepawali, was made in the present study. In order to assess the situation of noise levels in and around Balasore during two consecutive Deepawali of the year 2010 and 2011; noise monitoring was carried out in three different specified times (4:30-7:00 p.m., 7:00-10:30 p.m., 10:30 p.m.-1:00 a.m.). Noise descriptors such as L10, L50, L90, Leq, noise pollution level and noise climate were assessed to reveal the extent of noise pollution in this festival of crackers. Permissible limit of noise levels (Leq) prescribed by WHO during the festival was 100 dB and Lmax must not exceed 110 dB during such occasion. However, in all the cases Lmax and NPL values exceeded 110 dB, while Leq values ranged from 92.9 to 101.9 dB during 2010 Deepawali and 81.5 to 100.8 dB during 2011 Deepawali. On the other hand, all the noise monitoring sites belonged to residential areas. The assessed noise levels during such festivity are much more than 55/45 dB i.e. prescribed for residential areas for day/night time by CPCB. However, it was observed that the noise of Deepawali (Leq) decreased considerably and was less during 2011 than 2010. These may be due to increased environmental awareness among the public. Subsequently, the people of Balasore prefered to celebrate Deepawali, the festival of lights without sound and smoke. Noise policy should also be worked out for a better understanding of such local, social and cultural festivals in which annoyance arise.

  3. A Technique of Teaching the Principle of Equivalence at Ground Level

    Science.gov (United States)

    Lubrica, Joel V.

    2016-01-01

    This paper presents one way of demonstrating the Principle of Equivalence in the classroom. Teaching the Principle of Equivalence involves someone experiencing acceleration through empty space, juxtaposed with the daily encounter with gravity. This classroom activity is demonstrated with a water-filled bottle containing glass marbles and…

  4. Sources and levels of background noise in the NASA Ames 40- by 80-foot wind tunnel

    Science.gov (United States)

    Soderman, Paul T.

    1988-01-01

    Background noise levels are measured in the NASA Ames Research Center 40- by 80-Foot Wind Tunnel following installation of a sound-absorbent lining on the test-section walls. Results show that the fan-drive noise dominated the empty test-section background noise at airspeeds below 120 knots. Above 120 knots, the test-section broadband background noise was dominated by wind-induced dipole noise (except at lower harmonics of fan blade-passage tones) most likely generated at the microphone or microphone support strut. Third-octave band and narrow-band spectra are presented for several fan operating conditions and test-section airspeeds. The background noise levels can be reduced by making improvements to the microphone wind screen or support strut. Empirical equations are presented relating variations of fan noise with fan speed or blade-pitch angle. An empirical expression for typical fan noise spectra is also presented. Fan motor electric power consumption is related to the noise generation. Preliminary measurements of sound absorption by the test-section lining indicate that the 152 mm thick lining will adequately absorb test-section model noise at frequencies above 300 Hz.

  5. Assessment of noise levels generated by music shops in an urban city in Nigeria.

    Science.gov (United States)

    Ebare, M N; Omuemu, V O; Isah, E C

    2011-09-01

    To assess the level of noise generated by music shops in an urban city in Nigeria. Cross-sectional, descriptive study. The study involved music shops in three out of eight identified clusters of market areas in Benin City. A semi-structured, researcher-administered questionnaire was also used to collect data from music shop owners. Noise levels generated by speakers in the music shops were measured using a sound level meter, and blood pressure measurements were taken with a mercury sphygmomanometer. Of the 250 music shops studied, more than 90.0% generated noise levels >85 dB, and 54.8% had a continuous pattern of noise. Longer duration of working years was significantly associated with decreased hearing (P = 0.01), shouting when talking (P = 0.04) and high blood pressure (P = 0.003). The position of music dealers in relation to the speakers was significantly associated with shouting when talking (P = 0.000). A significant association was found between higher levels of noise and high blood pressure (P = 0.004). This study found very high levels of noise in music shops, which could be a source of occupational noise exposure among music dealers. Enlightenment campaigns on the hazards of exposure to loud noise and periodic audiometry examinations are recommended for this occupational group. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  6. Equivalent magnetic noise reduction at high frequency range due to polarized direction optimization in Terfenol-D/Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} magnetoelectric laminate sensors

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Cong, E-mail: fangcong86@gmail.com [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Ma, Jiashuai; Yao, Meng [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Di, Wenning; Lin, Di; Xu, Haiqing; Wang, Wei [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China); Luo, Haosu, E-mail: hsluo@mail.sic.ac.cn [Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2017-02-01

    In this paper, we investigate the responsivities and output voltage noise power spectral densities of magnetoelectric (ME) laminate sensors, consisting of length magnetized Terfenol-D alloys and transverse/width poled Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} (PMNT) crystals (i.e. L-T mode and L-W mode respectively), which are directly integrated with custom-build low noise charge amplifier circuits. Both the theoretical analyses and experimental results prove that the L-W mode sensor with the optimized polarized direction of the PMNT plate possesses lower magnetic detection limit at the interested high frequency range of 10 kHz≤f≤50 kHz. The equivalent magnetic noise (EMN) of the L-W mode sensor is 0.78 pT/Hz{sup 1/2} at 30 kHz, which is about 1.7 times lower than the 1.35 pT/Hz{sup 1/2} for conventional L-T mode sensor. Furthermore, an effective method of using operational amplifiers with low equivalent input noise voltage and employing ME laminate composites with high voltage coefficient to reduce the EMNs of the ME laminate sensors at high frequency range has been established. - Highlights: • We present fabrications and properties of the L-T and L-T mode ME composites. • The equivalent magnetic noise levels at high frequency are measured. • The equivalent magnetic noise of the L-W mode sensor is 0.78 pT/Hz{sup 1/2} at 30 kHz. • The dominated noise source can be confirmed from OPA at high frequency range.

  7. Environmental impact of noise levels in and around opencast bauxite mine.

    Science.gov (United States)

    Kisku, G C; Barman, S C; Kidwai, M M; Bhargava, S K

    2002-01-01

    Until recently, noise pollution has not been paid adequate attention as air, water and land pollution. In order to assess (predict) the impact of bauxite mine noise on employees health and in and around bauxite mine environment, general noise sources and equipment noise were monitored. All these noise sources were compared with prescribed standard noise levels laid down by Central Pollution Control Board (CPCB). Data has also been compared with reference site, north block hill top which is barren and virgin plateau/top covered with grass only and free from human interference. Equipment noise levels were much higher than the other zone of the mine which does not have the corresponding standards. Rock breaker recorded the highest noise level with 73.1 +/- 14.2 to 89.5 +/- 10.1 dB (A) while from ripper dozer it was least with 61.0 +/- 17.3 to 76.2 +/- 6.2 dB (A). Meteorological parameters did not have much influence upon equipment noise up to 100 feet from the source.

  8. Derivation of a reference dose and drinking water equivalent level for 1,2,3-trichloropropane.

    Science.gov (United States)

    Tardiff, Robert G; Carson, M Leigh

    2010-06-01

    In some US potable water supplies, 1,2,3-trichloropropane (TCP) has been present at ranges of non-detect to less than 100 ppb, resulting from past uses. In subchronic oral studies, TCP produced toxicity in kidneys, liver, and other tissues. TCP administered by corn oil gavage in chronic studies produced tumors at multiple sites in rats and mice; however, interpretation of these studies was impeded by substantial premature mortality. Drinking water equivalent levels (DWELs) were estimated for a lifetime of consumption by applying biologically-based safety/risk assessment approaches, including Monte Carlo techniques, and with consideration of kinetics and modes of action, to possibly replace default assumptions. Internationally recognized Frameworks for human relevance of animal data were employed to interpret the findings. Calculated were a reference dose (=39 microg/kg d) for non-cancer and Cancer Values (CV) (=10-14 microg/kg d) based on non-linear dose-response relationships for mutagenicity as a precursor of cancer. Lifetime Average Daily Intakes (LADI) are 3130 and 790-1120 microg/person-d for non-cancer and cancer, respectively. DWELs, estimated by applying a relative source contribution (RSC) of 50% to the LADIs, are 780 and 200-280 microg/L for non-cancer and cancer, respectively. These DWELs may inform establishment of formal/informal guidelines and standards to protect public health. Copyright 2010 Elsevier Ltd. All rights reserved.

  9. Environmental noise levels affect the activity budget of the Florida manatee

    Science.gov (United States)

    Miksis-Olds, Jennifer L.; Donaghay, Percy L.; Miller, James H.; Tyack, Peter L.

    2005-09-01

    Manatees inhabit coastal bays, lagoons, and estuaries because they are dependent on the aquatic vegetation that grows in shallow waters. Food requirements force manatees to occupy the same areas in which human activities are the greatest. Noise produced from human activities has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. This study quantifies the behavioral responses of manatees to both changing levels of ambient noise and transient noise sources. Results indicate that elevated environmental noise levels do affect the overall activity budget of this species. The proportion of time manatees spend feeding, milling, and traveling in critical habitats changed as a function of noise level. More time was spent in the directed, goal-oriented behaviors of feeding and traveling, while less time was spent milling when noise levels were highest. The animals also responded to the transient noise of approaching vessels with changes in behavioral state and movements out of the geographical area. This suggests that manatees detect and respond to changes in environmental noise levels. Whether these changes legally constitute harassment and produce biologically significant effects need to be addressed with hypothesis-driven experiments and long-term monitoring. [For Animal Bioacoustics Best Student Paper Award.

  10. A comparison of high-frequency noise levels on Cascadia Initiative ocean-bottom seismometers

    Science.gov (United States)

    Hilmo, R.; Wilcock, W. S. D.; Roland, E. C.; Bodin, P.; Connolly, J.

    2017-12-01

    The Cascadia Initiative (CI) included a four-year deployment of 70 ocean bottom seismometers (OBSs) on the Cascadia subduction zone and the Juan de Fuca plate for the purposes of characterizing seismicity and imaging the Earth's interior. The Cascadia subduction zone megathrust exhibits very low rates of seismicity relative to most other subduction zones, and there is great motivation to understand deformation on the megathrust because of its potential to produce a catastrophic M9 earthquake. An understanding of earthquake detectability of the CI network, based on knowledge of noise levels, could contribute to the interpretation of earthquake catalogs derived from the experiment and aid in the design of future networks. This project is aimed at estimating these thresholds of local earthquake detectability and how they change across the array both geographically and temporally. We characterize background noise levels recorded from 0.1 to 20 Hz with an emphasis on the frequency band used to detect local seismicity ( 3-15 Hz) to understand how noise levels depend on instrument design and environmental parameters including seafloor depth, season and oceanographic conditions. Our initial analysis of 3 weeks of vertical channel data in September, January, and May 2012-2013 shows that noise increase significantly moving from the continental shelf to deeper water. Noise levels at a given depth vary with instrument type but further analysis is required to determine whether this reflects variations in instrumental noise and ground coupling noise or errors in the scaling of the instrument response. There is also a strong seasonality in recorded noise levels at some frequencies, with winter noise levels exceeding spring and fall noise levels by up to 10 decibels in both the microseism band and in the fin whale calling band (15-20 Hz). In contrast, the seasonal noise level in the local seismicity band for a given instrument type and location shows smaller noise variation

  11. Studies on assessment of traffic noise level in Aurangabad city, India

    Directory of Open Access Journals (Sweden)

    B J Bhosale

    2010-01-01

    Full Text Available With the rapid rate of urbanization of Aurangabad city due to the expanding industrialization, the problem of noise pollution has become a concern for urban dwellers and government authority too. Noise pollution due to vehicular traffic is one of the growing environmental problems of urban centers. The study deals with the assessment of traffic noise levels in Aurangabad city. With respect to the total number of vehicles passing the road in unit time, which was surveyed by direct count method, six different sites from Aurangabad city, viz., Nagar Naka, Kranti Chowk, CIDCO bus stand, Railway station area, Dhoot Hospital and Baba petrol pump were selected to study the vehicular noise level. Noise measurements were carried out at these six locations on both working day and holiday during the peak traffic hours, i.e. 8:00 a.m. - 11:a.m., 1:00 p.m. - 4:00 p.m. and 5:00 p.m. - 8:00 p.m., in the morning, afternoon and evening sessions, respectively, after 5 minutes time interval. The noise level was monitored using noise level meter. The results obtained from this investigation showed that the Nagar Naka, Kranti chowk and CIDCO bus stand area have dense traffic zones when compared with the Railway station area, Dhoot Hospital and Baba petrol pump. The minimum and the maximum noise levels are 74 and 86 dB, respectively, on working day and 70 and 81 dB, respectively, on holiday. The measured noise level values exceed the prescribed noise level.

  12. STUDY ON NOISE LEVEL GENERATED BY HUMAN ACTIVITIES IN SIBIU CITY, ROMANIA

    Directory of Open Access Journals (Sweden)

    Cristina STANCA-MOISE

    2014-10-01

    Full Text Available In this paper I have proposed an analysis and monitoring of the noise sources in the open spaces of air traffic, rail and car in Sibiu. From centralizing data obtained from the analysis of the measurements performed with equipment noise levels, we concluded that the noise and vibration produced by means of Transportation (air, road, rail can affect human health if they exceed limits. Noise is present and part of our lives and always a source of pollution as any of modern man is not conscious.

  13. Sedimentary noise and sea levels linked to land-ocean water exchange and obliquity forcing.

    Science.gov (United States)

    Li, Mingsong; Hinnov, Linda A; Huang, Chunju; Ogg, James G

    2018-03-08

    In ancient hothouses lacking ice sheets, the origins of large, million-year (myr)-scale sea-level oscillations remain a mystery, challenging current models of sea-level change. To address this mystery, we develop a sedimentary noise model for sea-level changes that simultaneously estimates geologic time and sea level from astronomically forced marginal marine stratigraphy. The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag-1 autocorrelation coefficient (ρ 1 ). Noise modeling of Lower Triassic marine slope stratigraphy in South China reveal evidence for global sea-level variations in the Early Triassic hothouse that are anti-phased with continental water storage variations in the Germanic Basin. This supports the hypothesis that long-period (1-2 myr) astronomically forced water mass exchange between land and ocean reservoirs is a missing link for reconciling geological records and models for sea-level change during non-glacial periods.

  14. Ambient Noise Levels in Acute Neonatal Intensive Care Unit of a Tertiary Referral Hospital

    Directory of Open Access Journals (Sweden)

    Sonia R. B D'Souza

    2017-10-01

    Full Text Available Background: Advances in neonatal care have resulted in improved survival of neonates admitted to the intensive care of the Neonatal Intensive Care Unit (NICU. However, the NCU may be an inappropriate milieu, with presence of overwhelming stimuli, most potent being the continuous presence of noise in the ambience of the NICU. Aim and Objectives: To determine and describe the ambient noise levels in the acute NICU of a tertiary referral hospital. Material and Methods: The ambient noise, in this study was the background sound existing in the environment of the acute NICU of a tertiary referral hospital in South India. The ambient noise levels were analyzed by an audiologist and acoustical engineer using a standardized and calibrated Sound Level Meter (SLM i.e., the Hand Held Analyzer type 2250, Brüel and Kjær, Denmark on a weighted frequency A and reported as dB (A. Results: The ambient noise levels were timed measurements yielded by the SLM in terms of L eq, L as well as L exceeded the standard A 10 Aeqmax levels (Leq< 45 dB, L ≤ 50 dB, and Lmax ≤ 65 10 dB.The L eq ranged from 59.4 to 62.12 dB A. A Ventilators with alarms caused the maximum amount of ambient noise yielding a L Sound Pressure Level AF (SPL of 82.14 dB A. Conclusion: The study has found high levels of ambient noise in the acute NICU. Though there are several measures to reduce the ambient noise levels in the NICU, it is essential to raise awareness among health care personnel regarding the observed ambient noise levels and its effects on neonates admitted to the NICU.

  15. A comparative study of noise pollution levels in some selected areas in Ilorin Metropolis, Nigeria.

    Science.gov (United States)

    Oyedepo, Olayinka S; Saadu, Abdullahi A

    2009-11-01

    The noise pollution is a major problem for the quality of life in urban areas. This study was conducted to compare the noise pollution levels at busy roads/road junctions, passengers loading parks, commercial, industrial and residential areas in Ilorin metropolis. A total number of 47-locations were selected within the metropolis. Statistical analysis shows significant difference (P noise pollution levels between industrial areas and low density residential areas, industrial areas and high density areas, industrial areas and passengers loading parks, industrial areas and commercial areas, busy roads/road junctions and low density areas, passengers loading parks and commercial areas and commercial areas and low density areas. There is no significant difference (P > 0.05) in noise pollution levels between industrial areas and busy roads/road junctions, busy roads/road junctions and high density areas, busy roads/road junctions and passengers loading parks, busy roads/road junctions and commercial areas, passengers loading parks and high density areas, passengers loading parks and commercial areas and commercial areas and high density areas. The results show that Industrial areas have the highest noise pollution levels (110.2 dB(A)) followed by busy roads/Road junctions (91.5 dB(A)), Passengers loading parks (87.8 dB(A)) and Commercial areas (84.4 dB(A)). The noise pollution levels in Ilorin metropolis exceeded the recommended level by WHO at 34 of 47 measuring points. It can be concluded that the city is environmentally noise polluted and road traffic and industrial machineries are the major sources of it. Noting the noise emission standards, technical control measures, planning and promoting the citizens awareness about the high noise risk may help to relieve the noise problem in the metropolis.

  16. Modeling signal-to-noise ratio of otoacoustic emissions in workers exposed to different industrial noise levels

    Directory of Open Access Journals (Sweden)

    Parvin Nassiri

    2016-01-01

    Full Text Available Introduction: Noise is considered as the most common cause of harmful physical effects in the workplace. A sound that is generated from within the inner ear is known as an otoacoustic emission (OAE. Distortion-product otoacoustic emissions (DPOAEs assess evoked emission and hearing capacity. The aim of this study was to assess the signal-to-noise ratio in different frequencies and at different times of the shift work in workers exposed to various levels of noise. It was also aimed to provide a statistical model for signal-to-noise ratio (SNR of OAEs in different frequencies based on the two variables of sound pressure level (SPL and exposure time. Materials and Methods: This case–control study was conducted on 45 workers during autumn 2014. The workers were divided into three groups based on the level of noise exposure. The SNR was measured in frequencies of 1000, 2000, 3000, 4000, and 6000 Hz in both ears, and in three different time intervals during the shift work. According to the inclusion criterion, SNR of 6 dB or greater was included in the study. The analysis was performed using repeated measurements of analysis of variance, spearman correlation coefficient, and paired samples t-test. Results: The results showed that there was no statistically significant difference between the three exposed groups in terms of the mean values of SNR (P > 0.05. Only in signal pressure levels of 88 dBA with an interval time of 10:30–11:00 AM, there was a statistically significant difference between the right and left ears with the mean SNR values of 3000 frequency (P = 0.038. The SPL had a significant effect on the SNR in both the right and left ears (P = 0.023, P = 0.041. The effect of the duration of measurement on the SNR was statistically significant in both the right and left ears (P = 0.027, P < 0.001. Conclusion: The findings of this study demonstrated that after noise exposure during the shift, SNR of OAEs reduced from the

  17. The Relationship between Personality Type and Acceptable Noise Levels: A Pilot Study

    OpenAIRE

    Franklin, Cliff; Johnson, Laura V.; White, Letitia; Franklin, Clay; Smith-Olinde, Laura

    2013-01-01

    Objectives. This study examined the relationship between acceptable noise level (ANL) and personality. ANL is the difference between a person’s most comfortable level for speech and the loudest level of background noise they are willing to accept while listening to speech. Design. Forty young adults with normal hearing participated. ANLs were measured and two personality tests (Big Five Inventory, Myers-Briggs Type Indicator) were administered. Results. The analysis revealed a correlation bet...

  18. Preferred listening levels of mobile phone programs when considering subway interior noise.

    Science.gov (United States)

    Yu, Jyaehyoung; Lee, Donguk; Han, Woojae

    2016-01-01

    Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s). The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB), music, game] for 30 min using a tablet personal computer with an earphone. The participants' earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

  19. Preferred listening levels of mobile phone programs when considering subway interior noise

    Directory of Open Access Journals (Sweden)

    Jyaehyoung Yu

    2016-01-01

    Full Text Available Today, people listen to music loud using personal listening devices. Although a majority of studies have reported that the high volume played on these listening devices produces a latent risk of hearing problems, there is a lack of studies on "double noise exposures" such as environmental noise plus recreational noise. The present study measures the preferred listening levels of a mobile phone program with subway interior noise for 74 normal-hearing participants in five age groups (ranging from 20s to 60s. The speakers presented the subway interior noise at 73.45 dB, while each subject listened to three application programs [Digital Multimedia Broadcasting (DMB, music, game] for 30 min using a tablet personal computer with an earphone. The participants′ earphone volume levels were analyzed using a sound level meter and a 2cc coupler. Overall, the results showed that those in their 20s listened to the three programs significantly louder with DMB set at significantly higher volume levels than for the other programs. Higher volume levels were needed for middle frequency compared to the lower and higher frequencies. We concluded that any potential risk of noise-induced hearing loss for mobile phone users should be communicated when users listen regularly, although the volume level was not high enough that the users felt uncomfortable. When considering individual listening habits on mobile phones, further study to predict total accumulated environmental noise is still needed.

  20. Maintaining reduced noise levels in a resource-constrained neonatal intensive care unit by operant conditioning.

    Science.gov (United States)

    Ramesh, A; Denzil, S B; Linda, R; Josephine, P K; Nagapoornima, M; Suman Rao, P N; Swarna Rekha, A

    2013-03-01

    To evaluate the efficacy of operant conditioning in sustaining reduced noise levels in the neonatal intensive care unit (NICU). Quasi-experimental study on quality of care. Level III NICU of a teaching hospital in south India. 26 staff employed in the NICU. (7 Doctors, 13 Nursing staff and 6 Nursing assistants). Operant conditioning of staff activity for 6 months. This method involves positive and negative reinforcement to condition the staff to modify noise generating activities. Comparing noise levels in decibel: A weighted [dB (A)] before conditioning with levels at 18 and 24 months after conditioning. Decibel: A weighted accounts for noise that is audible to human ears. Operant conditioning for 6 months sustains the reduced noise levels to within 62 dB in ventilator room 95% CI: 60.4 - 62.2 and isolation room (95% CI: 55.8 - 61.5). In the preterm room, noise can be maintained within 52 dB (95% CI: 50.8 - 52.6). This effect is statistically significant in all the rooms at 18 months (P = 0.001). At 24 months post conditioning there is a significant rebound of noise levels by 8.6, 6.7 and 9.9 dB in the ventilator, isolation and preterm room, respectively (P =0.001). Operant conditioning for 6 months was effective in sustaining reduced noise levels. At 18 months post conditioning, the noise levels were maintained within 62 dB (A), 60 dB (A) and 52 dB (A) in the ventilator, isolation and pre-term room, respectively. Conditioning needs to be repeated at 12 months in the ventilator room and at 18 months in the other rooms.

  1. Prediction and comparison of noise levels from ground and elevated flare systems

    International Nuclear Information System (INIS)

    Obasi, E.

    2009-01-01

    Flaring is a process to dispose of hydrocarbons during clean-up, emergency shut downs or dispose a small volume waste streams of mixed gasses that cannot easily or safely be separated. This presentation discussed flaring as a noise issue. It focused on flaring noise characterization; flare noise modeling; flare sound power levels; and flare sound pressure level comparison at a distance of 1.5 km. The presentation included a photograph of flaring at a gas plant in Nigeria. The presentation listed some of the potential health effects associated with long term exposure to excessive noise, such as hearing loss; headaches; stress; fatigue; sleep disturbance; and high blood pressure. Companies flare gas to dispose waste gases in a safe and reliable manner through combustion and to depressurize gas lines during maintenance and emergencies. This presentation also discussed ground and elevated flares; components of flare noise characterization; and key factors affecting flare noise. A model to predict flaring noise was also presented. It demonstrated that at the same gas mass flow rate, the noise level from elevated flare stacks are significantly higher than ground flares. tabs., figs.

  2. Prediction and comparison of noise levels from ground and elevated flare systems

    Energy Technology Data Exchange (ETDEWEB)

    Obasi, E. [Stantec Consulting Ltd., Surrey, BC (Canada)

    2009-07-01

    Flaring is a process to dispose of hydrocarbons during clean-up, emergency shut downs or dispose a small volume waste streams of mixed gasses that cannot easily or safely be separated. This presentation discussed flaring as a noise issue. It focused on flaring noise characterization; flare noise modeling; flare sound power levels; and flare sound pressure level comparison at a distance of 1.5 km. The presentation included a photograph of flaring at a gas plant in Nigeria. The presentation listed some of the potential health effects associated with long term exposure to excessive noise, such as hearing loss; headaches; stress; fatigue; sleep disturbance; and high blood pressure. Companies flare gas to dispose waste gases in a safe and reliable manner through combustion and to depressurize gas lines during maintenance and emergencies. This presentation also discussed ground and elevated flares; components of flare noise characterization; and key factors affecting flare noise. A model to predict flaring noise was also presented. It demonstrated that at the same gas mass flow rate, the noise level from elevated flare stacks are significantly higher than ground flares. tabs., figs.

  3. Background noise levels measured in the NASA Lewis 9- by 15-foot low-speed wind tunnel

    Science.gov (United States)

    Woodward, Richard P.; Dittmar, James H.; Hall, David G.; Kee-Bowling, Bonnie

    1994-01-01

    The acoustic capability of the NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel has been significantly improved by reducing the background noise levels measured by in-flow microphones. This was accomplished by incorporating streamlined microphone holders having a profile developed by researchers at the NASA Ames Research Center. These new holders were fabricated for fixed mounting on the tunnel wall and for an axially traversing microphone probe which was mounted to the tunnel floor. Measured in-flow noise levels in the tunnel test section were reduced by about 10 dB with the new microphone holders compared with those measured with the older, less refined microphone holders. Wake interference patterns between fixed wall microphones were measured and resulted in preferred placement patterns for these microphones to minimize these effects. Acoustic data from a model turbofan operating in the tunnel test section showed that results for the fixed and translating microphones were equivalent for common azimuthal angles, suggesting that the translating microphone probe, with its significantly greater angular resolution, is preferred for sideline noise measurements. Fixed microphones can provide a local check on the traversing microphone data quality, and record acoustic performance at other azimuthal angles.

  4. Experimental Results on the Level Crossing Intervals of the Phase of Sine Wave Plus Noise

    Science.gov (United States)

    Youssef, Neji; Munakata, Tsutomu; Mimaki, Tadashi

    1993-03-01

    Experimental study was made on the level crossing intervals of a phase process of a sine wave plus narrow-band Gaussian noise. Since successive level crossings of phase do not necessarily occur alternately in the upward and downward direction due to the phase jump beyond 2π, the usual definitions of the probability densities of the level crossing intervals for continuous random processes are not applicable in the case of the phase process. Therefore, the probability densities of level crossing intervals of phase process are newly defined. Measurements of these densities were performed for noise having lowpass spectra of Gaussian and 7th order Butterworth types. Results are given for various values of the signal-to-noise power ratio and of the crossing level, and compared with corresponding approximation developed under the assumption of quasi-independence. The validity of the assumption depends on the spectrum shape of the noise.

  5. Measurement of speech levels in the presence of time varying background noise

    Science.gov (United States)

    Pearsons, K. S.; Horonjeff, R.

    1982-01-01

    Short-term speech level measurements which could be used to note changes in vocal effort in a time varying noise environment were studied. Knowing the changes in speech level would in turn allow prediction of intelligibility in the presence of aircraft flyover noise. Tests indicated that it is possible to use two second samples of speech to estimate long term root mean square speech levels. Other tests were also performed in which people read out loud during aircraft flyover noise. Results of these tests indicate that people do indeed raise their voice during flyovers at a rate of about 3-1/2 dB for each 10 dB increase in background level. This finding is in agreement with other tests of speech levels in the presence of steady state background noise.

  6. Relationship between lighting and noise levels and productivity of the occupants in automotive assembly industry.

    Science.gov (United States)

    Akbari, Jafar; Dehghan, Habibollah; Azmoon, Hiva; Forouharmajd, Farhad

    2013-01-01

    Work environment affects human productivity and his performance. The aims of this study were to investigate the effects of lighting and noise levels on human productivity in the automotive assembly industry. Subjects were 181 workers from different parts of an automobile assembly industry. Illuminance (Lx) at the height of 30 inches from the surface of work station and noise (dBA) were locally measured. Also human productivity by the Goldsmith and Hersey scale (1980) was measured. Data were analyzed by using SPSS v20 Pearson correlation coefficient. The results showed that the relationship between noise level and human productivity is negative and significant (P productivity (P > 0.05). Based on the results, in assembly tasks, noise has a negative impact on human productivity, and lighting does not affect this. So, in order to increase employee productivity, noise control and reduction to less than the standard values (less than 85 dB) is necessary.

  7. Acceptable noise level with Danish, Swedish, and non-semantic speech materials

    DEFF Research Database (Denmark)

    Brännström, K Jonas; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    reported results from American studies. Generally, significant differences were seen between test conditions using different types of noise within ears in each population. Significant differences were seen for ANL across populations, also when the non-semantic ISTS was used as speech signal. Conclusions......Abstract Objective: Acceptable noise level (ANL) has been established as a method to quantify the acceptance of background noise while listening to speech presented at the most comfortable level. The aim of the present study was to generate Danish, Swedish, and a non-semantic version of the ANL...... test and investigate normal-hearing Danish and Swedish subjects' performance on these tests. Design: ANL was measured using Danish and Swedish running speech with two different noises: Speech-weighted amplitude-modulated noise, and multitalker speech babble. ANL was also measured using the non...

  8. An evaluation of primary school students' views about noise levels in school

    Directory of Open Access Journals (Sweden)

    Nermin Bulunuz

    2017-06-01

    Full Text Available Effective education and teaching requires keeping classroom noise levels within specific limits. The purpose of this study is to evaluate students’ views about the noise level in school, its effects, and control of it at two primary schools (one public school and one private school located in a district of Bursa - within the scope of the TÜBİTAK 1001 project numbered 114K738. The research sample consists of 432 third and fourth graders, 223 of whom are from the public school and 209 of whom are from the private school. To collect data, a 20-question survey was administered to the students, and noise measurements were carried out in the schools. According to the findings obtained from the analysis of the answers from the student questionnaire, the students think that the noise level is high especially during break times. In parallel with the student views, the average noise level at break time during recess was found to be 74.56 dBA at the private primary school and 82.18 dBA at the public primary school. These values are much higher than the limits prescribed in the Regulation on Assessment and Management of Environmental Noise in Turkey (RAMEN European Union Harmonization Laws. The research findings show that this important problem must be dealt with urgently, and substantive efforts and activities must be launched to reduce high noise levels in schools.

  9. Effects of traffic noise on tree frog stress levels, immunity, and color signaling.

    Science.gov (United States)

    Troïanowski, Mathieu; Mondy, Nathalie; Dumet, Adeline; Arcanjo, Caroline; Lengagne, Thierry

    2017-10-01

    During the last decade, many studies have focused on the detrimental effects of noise pollution on acoustic communication. Surprisingly, although it is known that noise exposure strongly influences health in humans, studies on wildlife remain scarce. In order to gain insight into the consequences of traffic noise exposure, we experimentally manipulated traffic noise exposure as well as the endocrine status of animals to investigate physiological and phenotypic consequences of noise pollution in an anuran species. We showed that noise exposure increased stress hormone level and induced an immunosuppressive effect. In addition, both traffic noise exposure and stress hormone application negatively impacted H. arborea vocal sac coloration. Moreover, our results suggest profound changes in sexual selection processes because the best quality males with initial attractive vocal sac coloration were the most impacted by noise. Hence, our study suggests that the recent increases in anthropogenic noise worldwide might affect a broader range of animal species than previously thought, because of alteration of visual signals and immunity. Generalizing these results to other taxa is crucial for the conservation of biodiversity in an increasingly noisy world. © 2017 Society for Conservation Biology.

  10. Effect of background noise on neuronal coding of interaural level difference cues in rat inferior colliculus.

    Science.gov (United States)

    Mokri, Yasamin; Worland, Kate; Ford, Mark; Rajan, Ramesh

    2015-07-01

    Humans can accurately localize sounds even in unfavourable signal-to-noise conditions. To investigate the neural mechanisms underlying this, we studied the effect of background wide-band noise on neural sensitivity to variations in interaural level difference (ILD), the predominant cue for sound localization in azimuth for high-frequency sounds, at the characteristic frequency of cells in rat inferior colliculus (IC). Binaural noise at high levels generally resulted in suppression of responses (55.8%), but at lower levels resulted in enhancement (34.8%) as well as suppression (30.3%). When recording conditions permitted, we then examined if any binaural noise effects were related to selective noise effects at each of the two ears, which we interpreted in light of well-known differences in input type (excitation and inhibition) from each ear shaping particular forms of ILD sensitivity in the IC. At high signal-to-noise ratios (SNR), in most ILD functions (41%), the effect of background noise appeared to be due to effects on inputs from both ears, while for a large percentage (35.8%) appeared to be accounted for by effects on excitatory input. However, as SNR decreased, change in excitation became the dominant contributor to the change due to binaural background noise (63.6%). These novel findings shed light on the IC neural mechanisms for sound localization in the presence of continuous background noise. They also suggest that some effects of background noise on encoding of sound location reported to be emergent in upstream auditory areas can also be observed at the level of the midbrain. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Rat hippocampal alterations could underlie behavioral abnormalities induced by exposure to moderate noise levels.

    Science.gov (United States)

    Uran, S L; Aon-Bertolino, M L; Caceres, L G; Capani, F; Guelman, L R

    2012-08-30

    Noise exposure is known to affect auditory structures in living organisms. However, it should not be ignored that many of the effects of noise are extra-auditory. Previous findings of our laboratory demonstrated that noise was able to induce behavioral alterations that are mainly related to the cerebellum (CE) and the hippocampus (HC). Therefore, the aim of this work was to reveal new data about the vulnerability of developing rat HC to moderate noise levels through the assessment of potential histological changes and hippocampal-related behavioral alterations. Male Wistar rats were exposed to noise (95-97 dB SPL, 2h daily) either for 1 day (acute noise exposure, ANE) or between postnatal days 15 and 30 (sub-acute noise exposure, SANE). Hippocampal histological evaluation as well as short (ST) and long term (LT) habituation and recognition memory assessments were performed. Results showed a mild disruption in the different hippocampal regions after ANE and SANE schemes, along with significant behavioral abnormalities. These data suggest that exposure of developing rats to noise levels of moderate intensity is able to trigger changes in the HC, an extra-auditory structure of the Central Nervous System (CNS), that could underlie the observed behavioral effects. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Advantages of binaural amplification to acceptable noise level of directional hearing aid users.

    Science.gov (United States)

    Kim, Ja-Hee; Lee, Jae Hee; Lee, Ho-Ki

    2014-06-01

    The goal of the present study was to examine whether Acceptable Noise Levels (ANLs) would be lower (greater acceptance of noise) in binaural listening than in monaural listening condition and also whether meaningfulness of background speech noise would affect ANLs for directional microphone hearing aid users. In addition, any relationships between the individual binaural benefits on ANLs and the individuals' demographic information were investigated. Fourteen hearing aid users (mean age, 64 years) participated for experimental testing. For the ANL calculation, listeners' most comfortable listening levels and background noise level were measured. Using Korean ANL material, ANLs of all participants were evaluated under monaural and binaural amplification with a counterbalanced order. The ANLs were also compared across five types of competing speech noises, consisting of 1- through 8-talker background speech maskers. Seven young normal-hearing listeners (mean age, 27 years) participated for the same measurements as a pilot testing. The results demonstrated that directional hearing aid users accepted more noise (lower ANLs) with binaural amplification than with monaural amplification, regardless of the type of competing speech. When the background speech noise became more meaningful, hearing-impaired listeners accepted less amount of noise (higher ANLs), revealing that ANL is dependent on the intelligibility of the competing speech. The individuals' binaural advantages in ANLs were significantly greater for the listeners with longer experience of hearing aids, yet not related to their age or hearing thresholds. Binaural directional microphone processing allowed hearing aid users to accept a greater amount of background noise, which may in turn improve listeners' hearing aid success. Informational masking substantially influenced background noise acceptance. Given a significant association between ANLs and duration of hearing aid usage, ANL measurement can be useful for

  13. Evaluation of noise pollution level in the operating rooms of hospitals: A study in Iran.

    Science.gov (United States)

    Giv, Masoumeh Dorri; Sani, Karim Ghazikhanlou; Alizadeh, Majid; Valinejadi, Ali; Majdabadi, Hesamedin Askari

    2017-06-01

    Noise pollution in the operating rooms is one of the remaining challenges. Both patients and physicians are exposed to different sound levels during the operative cases, many of which can last for hours. This study aims to evaluate the noise pollution in the operating rooms during different surgical procedures. In this cross-sectional study, sound level in the operating rooms of Hamadan University-affiliated hospitals (totally 10) in Iran during different surgical procedures was measured using B&K sound meter. The gathered data were compared with national and international standards. Statistical analysis was performed using descriptive statistics and one-way ANOVA, t -test, and Pearson's correlation test. Noise pollution level at majority of surgical procedures is higher than national and international documented standards. The highest level of noise pollution is related to orthopedic procedures, and the lowest one related to laparoscopic and heart surgery procedures. The highest and lowest registered sound level during the operation was 93 and 55 dB, respectively. Sound level generated by equipments (69 ± 4.1 dB), trolley movement (66 ± 2.3 dB), and personnel conversations (64 ± 3.9 dB) are the main sources of noise. The noise pollution of operating rooms are higher than available standards. The procedure needs to be corrected for achieving the proper conditions.

  14. Investigating impact of motor oil quality on vehicles engine induced noise level

    Directory of Open Access Journals (Sweden)

    I. Arefian

    2015-09-01

    Full Text Available Introduction: Vehicle engine id one of the main sources of noise which its level is influenced by various parameters. The aim of this study was to investigate the impact of motor oils quality before and after oil change on the variability of vehicle engine induced noise level. In this study it is tried to follow-up the efficacy of motor oil quality on engines sound level. Material and Method: First, engine noise of 94 vehicles were recorded for 30 seconds before and after oil change and all the vehicles technical information including mileage, type of motor oil, and type of vehicle were registered. Following, the recorded noises were calibrated in semi-anechoic chamber and the sound pressure levels were measured with A and C-weighting network and main octav bands, using a sound level meters. The obtained results analyzed using SPSS software version 17. Results: The effects of motor oil quality on different noise levels of engines were determined and a significant reduction in noise level of vehicles engine was observed. Investigation of the relationship between mileage and motor oil quality on various engines sound level manifested that vehicles with mileage ranged 100000-150000 miles had significant reduction in their sound pressure levels in comparison with other vehicles. Conclusion: The results revealed that engine oil is among factors reducing the vehicle engine induced noise level. Moreover, the engine oil type and the vehicle mileage are key variables which determine the impact of engine oil quality on reduction of the sound level of vehicles engine.

  15. Effects of pedagogical ideology on the perceived loudness and noise levels in preschools

    Science.gov (United States)

    Jonsdottir, Valdis; Rantala, Leena M.; Oskarsson, Gudmundur Kr.; Sala, Eeva

    2015-01-01

    High activity noise levels that result in detrimental effects on speech communication have been measured in preschools. To find out if different pedagogical ideologies affect the perceived loudness and levels of noise, a questionnaire study inquiring about the experience of loudness and voice symptoms was carried out in Iceland in eight private preschools, called “Hjalli model”, and in six public preschools. Noise levels were also measured in the preschools. Background variables (stress level, age, length of working career, education, smoking, and number of children per teacher) were also analyzed in order to determine how much they contributed toward voice symptoms and the experience of noisiness. Results indicate that pedagogical ideology is a significant factor for predicting noise and its consequences. Teachers in the preschool with tighter pedagogical control of discipline (the “Hjalli model”) experienced lower activity noise loudness than teachers in the preschool with a more relaxed control of behavior (public preschool). Lower noise levels were also measured in the “Hjalli model” preschool and fewer “Hjalli model” teachers reported voice symptoms. Public preschool teachers experienced more stress than “Hjalli model” teachers and the stress level was, indeed, the background variable that best explained the voice symptoms and the teacher's perception of a noisy environment. Discipline, structure, and organization in the type of activity predicted the activity noise level better than the number of children in the group. Results indicate that pedagogical ideology is a significant factor for predicting self-reported noise and its consequences. PMID:26356370

  16. Noise levels in neonatal intensive care unit and use of sound absorbing panel in the isolette.

    Science.gov (United States)

    Altuncu, E; Akman, I; Kulekci, S; Akdas, F; Bilgen, H; Ozek, E

    2009-07-01

    The purposes of this study were to measure the noise level of a busy neonatal intensive care unit (NICU) and to determine the effect of sound absorbing panel (SAP) on the level of noise inside the isolette. The sound pressure levels (SPL) of background noise, baby crying, alarms and closing of isolette's door/portholes were measured by a 2235-Brüel&Kjaer Sound Level Meter. Readings were repeated after applying SAP (3D pyramidal shaped open cell polyurethane foam) to the three lateral walls and ceiling of the isolette. The median SPL of background noise inside the NICU was 56dBA and it decreased to 47dBA inside the isolette. The median SPL of monitor alarms and baby crying inside the isolette were not different than SPL measured under radiant warmer (p>0.05). With SAP, the median SPL of temperature alarm inside the isolette decreased significantly from 82 to 72dBA, monitor alarm from 64 to 56dBA, porthole closing from 81 to 74dBA, and isolette door closing from 80 to 68dBA (pnoise produced by baby crying when SAP was used in the isolette (79dBA vs 69dBA, respectively) (pnoise. The noise level in our NICU is significantly above the universally recommended levels. Being inside the isolette protects infants from noise sources produced outside the isolette. However, very high noises are produced inside the isolette as well. Sound absorbing panel can be a simple solution and it attenuated the noise levels inside the isolette.

  17. 41 CFR 102-80.105 - What information must be included in an equivalent level of safety analysis?

    Science.gov (United States)

    2010-07-01

    ... REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Accident and Fire Prevention Equivalent Level.... Each analysis should describe potential reasonable worst case fire scenarios and their impact on the... and location of fuel items, space layout, building construction, openings and ventilation, suppression...

  18. Noiseonomics: the relationship between ambient noise levels in the sea and global economic trends.

    Science.gov (United States)

    Frisk, George V

    2012-01-01

    In recent years, the topic of noise in the sea and its effects on marine mammals has attracted considerable attention from both the scientific community and the general public. Since marine mammals rely heavily on acoustics as a primary means of communicating, navigating, and foraging in the ocean, any change in their acoustic environment may have an impact on their behavior. Specifically, a growing body of literature suggests that low-frequency, ambient noise levels in the open ocean increased approximately 3.3 dB per decade during the period 1950-2007. Here we show that this increase can be attributed primarily to commercial shipping activity, which in turn, can be linked to global economic growth. As a corollary, we conclude that ambient noise levels can be directly related to global economic conditions. We provide experimental evidence supporting this theory and discuss its implications for predicting future noise levels based on global economic trends.

  19. Application of the kurtosis statistic to the evaluation of the risk of hearing loss in workers exposed to high-level complex noise.

    Science.gov (United States)

    Zhao, Yi-Ming; Qiu, Wei; Zeng, Lin; Chen, Shan-Song; Cheng, Xiao-Ru; Davis, Robert I; Hamernik, Roger P

    2010-08-01

    Develop dose-response relations for two groups of industrial workers exposed to Gaussian or non-Gaussian (complex) types of continuous noises and to investigate what role, if any, the kurtosis statistic can play in the evaluation of industrial noise-induced hearing loss (NIHL). Audiometric and noise exposure data were acquired on a population (N = 195) of screened workers from a textile manufacturing plant and a metal fabrication facility located in Henan province of China. Thirty-two of the subjects were exposed to non-Gaussian (non-G) noise and 163 were exposed to a Gaussian (G) continuous noise. Each subject was given a general physical and an otologic examination. Hearing threshold levels (0.5-8.0 kHz) were age adjusted (ISI-1999) and the prevalence of NIHL at 3, 4, or 6 kHz was determined. The kurtosis metric, which is sensitive to the peak and temporal characteristics of a noise, was introduced into the calculation of the cumulative noise exposure metric. Using the prevalence of hearing loss and the cumulative noise exposure metric, a dose-response relation for the G and non-G noise-exposed groups was constructed. An analysis of the noise environments in the two plants showed that the noise exposures in the textile plant were of a Gaussian type with an Leq(A)8hr that varied from 96 to 105 dB whereas the exposures in the metal fabrication facility with an Leq(A)8hr = 95 dB were of a non-G type containing high levels (up to 125 dB peak SPL) of impact noise. The kurtosis statistic was used to quantify the deviation of the non-G noise environment from the Gaussian. The dose-response relation for the non-G noise-exposed subjects showed a higher prevalence of hearing loss for a comparable cumulative noise exposure than did the G noise-exposed subjects. By introducing the kurtosis variable into the temporal component of the cumulative noise exposure calculation, the two dose-response curves could be made to overlap, essentially yielding an equivalent noise

  20. The impact of noise level on students' learning performance at state elementary school in Medan

    Science.gov (United States)

    Buchari, Matondang, Nazaruddin

    2017-06-01

    This study was conducted to determine the level and impact of noise on pupils' learning performance that was observed through a survey at State Elementary School (SDN 060882), which is located on the corner of Abdullah Lubis Street and Pattimura Medan Street. The study was done by measuring the noise level using the Threshold Limit Value (TLV) by taking 24 locations as the measurement points. The results indicated that the noise levels exceeded the standard TLV >55 dBA as regulated in the Decree of the Minister of Environment No. KEP/48/MENLH/11/1996. According to the data processing, the noise level at school was 70.79 dBA. The classrooms were classified into noisy zones based on the Noise Mapping. Those in Red Zone which noise level were in the range of (69-75 dBA) were Class IIIa, Class IVb, and Class VI. In addition, those in Yellow Zone which were in the range of (65-69 dBA) were Class II, Class IIIa, Class IVa and Class V. The noise brought the physiological impact in the forms of dizziness that had the highest percentage of 22% and emotional and uncomfortable feeling of 21%; the communication impact of teacher's explanation disturbance of 22%; and Pupils' learning performance was evidenced to decline of 22%. Some improvements are suggested to reduce the noise such as the reposition of windows, acoustic material to cover the classrooms' wall, and bamboo trees or grasses as the barried around the school area.

  1. The control of superluminal group velocity in a system equivalent to the Y-type four-level atomic system

    International Nuclear Information System (INIS)

    Li Luming; Guo Hong; Xiao Feng; Peng Xiang; Chen Xuzong

    2005-01-01

    We study a new way to control the superluminal group velocity of light pulse in hot atomic gases with the five-level atomic configuration. The model of an equivalent Y-type four-level is applied and shows that the light goes faster by using an additional incoherent pumping field. The experiment is performed and shows in good agreement with our theoretical predictions

  2. [Environmental noise levels in 2 intensive care units in a tertiary care centre].

    Science.gov (United States)

    Ornelas-Aguirre, José Manuel; Zárate-Coronado, Olivia; Gaxiola-González, Fabiola; Neyoy-Sombra, Venigna

    2017-04-03

    The World Health Organisation (WHO) has established a maximum noise level of 40 decibels (dB) for an intensive care unit. The aim of this study was to compare the noise levels in 2 different intensive care units at a tertiary care centre. Using a cross-sectional design study, an analysis was made of the maximum noise level was within the intensive coronary care unit and intensive care unit using a digital meter. A measurement was made in 4 different points of each room, with 5minute intervals, for a period of 60minutes 7:30, 14:30, and 20:30. The means of the observations were compared with descriptive statistics and Mann-Whitney U. An analysis with Kruskal-Wallis test was performed to the mean noise level. The noise observed in the intensive care unit had a mean of 64.77±3.33dB (P=.08), which was similar to that in the intensive coronary care unit, with a mean of 60.20±1.58dB (P=.129). Around 25% or more of the measurements exceeded the level recommended by the WHO by up to 20 points. Noise levels measured in intensive care wards exceed the maximum recommended level for a hospital. It is necessary to design and implement actions for greater participation of health personnel in the reduction of environmental noise. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  3. Determination of the level of noise in nurseries and pre-schools and the teachers′ level of annoyance

    Directory of Open Access Journals (Sweden)

    Ozan Gokdogan

    2016-01-01

    Full Text Available Objective: The aim of this article is to determine the level of noise in nurseries and pre-schools and also to compare measured levels with standard levels and evaluate the teachers’ level of annoyance. Materials and Methods: The level of noise was measured in three different schools. A total of 162 students, whose ages were between 3 and 6 years, and 12 teachers were included the study. Every age groups’ level of noise was measured during sleeping, gaming, and eating activity. In addition, teachers’ annoyance was assessed in different age groups. Results: The 4- to 6-year-old groups were found to have higher level of sounds than 3-year-old group. Eating period was found to be the highest level of sound whereas sleeping was found the lowest. Furthermore, teachers’ annoyance was found higher as the age decreased. Conclusion: Nurseries and pre-schools have noisy environment both for the students and the teachers. High level of noise, which has bad effects on health, is a public health problem. Both the students’ families and teachers must be aware of this annoying situation.

  4. Noiseonomics: The relationship between ambient noise levels in the sea and global economic trends

    OpenAIRE

    Frisk, George V.

    2012-01-01

    In recent years, the topic of noise in the sea and its effects on marine mammals has attracted considerable attention from both the scientific community and the general public. Since marine mammals rely heavily on acoustics as a primary means of communicating, navigating, and foraging in the ocean, any change in their acoustic environment may have an impact on their behavior. Specifically, a growing body of literature suggests that low-frequency, ambient noise levels in the open ocean increas...

  5. Ambient Noise Levels in Acute Neonatal Intensive Care Unit of a Tertiary Referral Hospital

    OpenAIRE

    Sonia R. B D'Souza; Leslie Edward Lewis; Vijay Kumar; Ramesh Bhat Y; Jayashree Purkayastha; Hari Prakash

    2017-01-01

    Background: Advances in neonatal care have resulted in improved survival of neonates admitted to the intensive care of the Neonatal Intensive Care Unit (NICU). However, the NCU may be an inappropriate milieu, with presence of overwhelming stimuli, most potent being the continuous presence of noise in the ambience of the NICU. Aim and Objectives: To determine and describe the ambient noise levels in the acute NICU of a tertiary referral hospital. Material and Methods...

  6. Pilot study of methods and equipment for in-home noise level measurements.

    Science.gov (United States)

    Neitzel, Richard L; Heikkinen, Maire S A; Williams, Christopher C; Viet, Susan Marie; Dellarco, Michael

    2015-01-15

    Knowledge of the auditory and non-auditory effects of noise has increased dramatically over the past decade, but indoor noise exposure measurement methods have not advanced appreciably, despite the introduction of applicable new technologies. This study evaluated various conventional and smart devices for exposure assessment in the National Children's Study. Three devices were tested: a sound level meter (SLM), a dosimeter, and a smart device with a noise measurement application installed. Instrument performance was evaluated in a series of semi-controlled tests in office environments over 96-hour periods, followed by measurements made continuously in two rooms (a child's bedroom and a most used room) in nine participating homes over a 7-day period with subsequent computation of a range of noise metrics. The SLMs and dosimeters yielded similar A-weighted average noise levels. Levels measured by the smart devices often differed substantially (showing both positive and negative bias, depending on the metric) from those measured via SLM and dosimeter, and demonstrated attenuation in some frequency bands in spectral analysis compared to SLM results. Virtually all measurements exceeded the Environmental Protection Agency's 45 dBA day-night limit for indoor residential exposures. The measurement protocol developed here can be employed in homes, demonstrates the possibility of measuring long-term noise exposures in homes with technologies beyond traditional SLMs, and highlights potential pitfalls associated with measurements made by smart devices.

  7. A survey of acoustic conditions and noise levels in secondary school classrooms in England.

    Science.gov (United States)

    Shield, Bridget; Conetta, Robert; Dockrell, Julie; Connolly, Daniel; Cox, Trevor; Mydlarz, Charles

    2015-01-01

    An acoustic survey of secondary schools in England has been undertaken. Room acoustic parameters and background noise levels were measured in 185 unoccupied spaces in 13 schools to provide information on the typical acoustic environment of secondary schools. The unoccupied acoustic and noise data were correlated with various physical characteristics of the spaces. Room height and the amount of glazing were related to the unoccupied reverberation time and therefore need to be controlled to reduce reverberation to suitable levels for teaching and learning. Further analysis of the unoccupied data showed that the introduction of legislation relating to school acoustics in England and Wales in 2003 approximately doubled the number of school spaces complying with current standards. Noise levels were also measured during 274 lessons to examine typical levels generated during teaching activities in secondary schools and to investigate the influence of acoustic design on working noise levels in the classroom. Comparison of unoccupied and occupied data showed that unoccupied acoustic conditions affect the noise levels occurring during lessons. They were also related to the time spent in disruption to the lessons (e.g., students talking or shouting) and so may also have an impact upon student behavior in the classroom.

  8. Determination of Noise Level and Its Sources in the Neonatal Intensive Care Unit and Neonatal Ward

    Directory of Open Access Journals (Sweden)

    Mahdi Jahangir Blourchian

    2015-12-01

    Full Text Available Background: In Neonatal intensive care units (NICU different sound intensities and frequencies are produced from different sources, which may exert undesirable physiological effects on the infants. The aim of this study was to determine the noise level and its sources in the NICU and neonatal ward of Al-Zahra Hospital of Rasht, Iran. Methods: In this descriptive cross-sectional study, the intensity of the sounds generated by the internal and external sources in the NICU and neonatal ward was measured using a sound level meter device. The sound produced by each of the sources was individually calculated. Data were analyzed performing descriptive and analytical statistics, using SPSS version 19. Results: The mean noise levels in six rooms and a hallway during morning, afternoon and night shifts with the electromechanical devices turned on were 61.67±4.5, 61.32±4.32 and 60.71±4.56 dB, respectively. Moreover, with the devices tuned off the mean noise levels during morning, afternoon and evening shifts were 64.97±2.6, 60.6±1.29 and 57.91±4.73 dB, respectively. The differences between the mean noise levels in the neonatal wards (standard noise level=45 dB during each shift with the electromechanical devices turned on and off were statistically significant (P=0.002 and P

  9. Measuring and Assessment the Noise Level in Different Regions in Baghdad City And Compare it with The Allowable Levels

    Directory of Open Access Journals (Sweden)

    Ibtihaj Abdulwahhab Abdulrazzak

    2017-05-01

    Full Text Available This study includes measurement of the noise level of four regions in the city of Baghdad (industrial region, commercial region, residential region and quiet region and compare the value of noise in each region with the World Health Organization (WHO allowable limits, and the effect of noise on human health was explained. The "sound level meter (SLM" instrument measuring the noise value in the four regions, three measurement per month through one year was recorded (one measurement every ten days from 1/1/2015 to 30/12/2015. The noise level of the industrial region (75dB compared with the World Health Organization level allowable limit (65dB, while the commercial region (76.28dB versus (55dB and the residential region (74.94dB versus (50dB and the quiet region was (62.36dB versus (40dB of the (WHO allowable limit.

  10. Adaptive nonlocal means filtering based on local noise level for CT denoising

    International Nuclear Information System (INIS)

    Li, Zhoubo; Trzasko, Joshua D.; Lake, David S.; Blezek, Daniel J.; Manduca, Armando; Yu, Lifeng; Fletcher, Joel G.; McCollough, Cynthia H.

    2014-01-01

    Purpose: To develop and evaluate an image-domain noise reduction method based on a modified nonlocal means (NLM) algorithm that is adaptive to local noise level of CT images and to implement this method in a time frame consistent with clinical workflow. Methods: A computationally efficient technique for local noise estimation directly from CT images was developed. A forward projection, based on a 2D fan-beam approximation, was used to generate the projection data, with a noise model incorporating the effects of the bowtie filter and automatic exposure control. The noise propagation from projection data to images was analytically derived. The analytical noise map was validated using repeated scans of a phantom. A 3D NLM denoising algorithm was modified to adapt its denoising strength locally based on this noise map. The performance of this adaptive NLM filter was evaluated in phantom studies in terms of in-plane and cross-plane high-contrast spatial resolution, noise power spectrum (NPS), subjective low-contrast spatial resolution using the American College of Radiology (ACR) accreditation phantom, and objective low-contrast spatial resolution using a channelized Hotelling model observer (CHO). Graphical processing units (GPU) implementation of this noise map calculation and the adaptive NLM filtering were developed to meet demands of clinical workflow. Adaptive NLM was piloted on lower dose scans in clinical practice. Results: The local noise level estimation matches the noise distribution determined from multiple repetitive scans of a phantom, demonstrated by small variations in the ratio map between the analytical noise map and the one calculated from repeated scans. The phantom studies demonstrated that the adaptive NLM filter can reduce noise substantially without degrading the high-contrast spatial resolution, as illustrated by modulation transfer function and slice sensitivity profile results. The NPS results show that adaptive NLM denoising preserves the

  11. Effects of nocturnal railway noise on sleep fragmentation in young and middle-aged subjects as a function of type of train and sound level.

    Science.gov (United States)

    Saremi, Mahnaz; Grenèche, Jérôme; Bonnefond, Anne; Rohmer, Odile; Eschenlauer, Arnaud; Tassi, Patricia

    2008-12-01

    Due to undisputable effects of noise on sleep structure, especially in terms of sleep fragmentation, the expected development of railway transportation in the next few years might represent a potential risk factor for people living alongside the rail tracks. The aim of this study was to compare the effects of different types of train (freight, automotive, passenger) on arousal from sleep and to determine any differential impact as a function of sound level and age. Twenty young (16 women, 4 men; 25.8 years+/-2.6) and 18 middle-aged (15 women, 3 men; 52.2 years+/-2.5) healthy subjects participated in three whole-night polysomnographic recordings including one control night (35 dBA), and two noisy nights with equivalent noise levels of 40 or 50 dB(A), respectively. Arousal responsiveness increased with sound level. It was the highest in S2 and the lowest in REM sleep. Micro-arousals (3-10 s) occurred at a rate of 25-30%, irrespective of the type of train. Awakenings (>10 s) were produced more frequently by freight train than by automotive and passenger trains. Normal age-related changes in sleep were observed, but they were not aggravated by railway noise, thus questioning whether older persons are less sensitive to noise during sleep. These evidences led to the conclusion that microscopic detection of sleep fragmentation may provide advantageous information on sleep disturbances caused by environmental noises.

  12. [Preventive effects of sound insulation windows on the indoor noise levels in a street residential building in Beijing].

    Science.gov (United States)

    Guo, Bin; Huang, Jing; Guo, Xin-biao

    2015-06-18

    To evaluate the preventive effects of sound insulation windows on traffic noise. Indoor noise levels of the residential rooms (on both the North 4th ring road side and the campus side) with closed sound insulation windows were measured using the sound level meter, and comparisons with the simultaneously measured outdoor noise levels were made. In addition, differences of indoor noise levels between rooms with closed sound insulation windows and open sound insulation windows were also compared. The average outdoor noise levels of the North 4th ring road was higher than 70 dB(A), which exceeded the limitation stated in the "Environmental Quality Standard for Noise" (GB 3096-2008) in our country. However, with the sound insulation windows closed, the indoor noise levels reduced significantly to the level under 35 dB(A) (Pwindows had significant influence on the indoor noise levels (Pwindow, when the sound insulation windows were closed, the indoor noise levels reduced 18.8 dB(A) and 8.3 dB(A) in residential rooms facing North 4th ring road side and campus side, respectively. The results indicated that installation of insulation windows had significant noise reduction effects on street residential buildings especially on the rooms facing major traffic roads. Installation of the sound insulation windows has significant preventive effects on indoor noise in the street residential building.

  13. Entropy-Based Method of Choosing the Decomposition Level in Wavelet Threshold De-noising

    Directory of Open Access Journals (Sweden)

    Yan-Fang Sang

    2010-06-01

    Full Text Available In this paper, the energy distributions of various noises following normal, log-normal and Pearson-III distributions are first described quantitatively using the wavelet energy entropy (WEE, and the results are compared and discussed. Then, on the basis of these analytic results, a method for use in choosing the decomposition level (DL in wavelet threshold de-noising (WTD is put forward. Finally, the performance of the proposed method is verified by analysis of both synthetic and observed series. Analytic results indicate that the proposed method is easy to operate and suitable for various signals. Moreover, contrary to traditional white noise testing which depends on “autocorrelations”, the proposed method uses energy distributions to distinguish real signals and noise in noisy series, therefore the chosen DL is reliable, and the WTD results of time series can be improved.

  14. Does the acceptable noise level (ANL) predict hearing-aid use?

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Brännström, K Jonas

    2014-01-01

    OBJECTIVE: It has been suggested that individuals have an inherent acceptance of noise in the presence of speech, and that different acceptance of noise results in different hearing-aid (HA) use. The acceptable noise level (ANL) has been proposed for measurement of this property. It has been...... claimed that the ANL magnitude can predict hearing-aid use patterns. Many papers have been published reporting on different aspects of ANL, but none have challenged the predictive power of ANL. The purpose of this study was to discuss whether ANL can predict HA use and how more reliable ANL results can...... reviewed journals as well as a number of papers from trade journals, posters and oral presentations from audiology conventions. CONCLUSIONS: An inherent acceptance of noise in the presence of speech may exist, but no method for precise measurement of ANL is available. The ANL model for prediction of HA use...

  15. Combination therapy using antioxidants and low level laser therapy (LLLT) on noise induced hearing loss (NIHL)

    Science.gov (United States)

    Chang, So-Young; Lim, Sung Kyu; Lee, Min young; Chung, Phil-Sang; Jung, Jae-Yun; Rhee, Chung-Ku

    2016-02-01

    One of the most common factors that cause hearing disorders is noise trauma. Noise is an increasing hazard and it is pervasive, which makes it difficult to take precautions and prevent noise-induced hearing loss (NIHL). The prevalence of hearing loss among factory workers to be 42 %[1]. Ocupational noise induced hearing loss (ONIHL) continues to be a significant occupational hazard. ONIHL is permanent and may cause significant disability, for which there currently exists no cure, but is largely preventable. More than 30 million Americans are potentially exposed to hazardous noise levels in occupations such as transportation, construction, and coal mining, as well as recreationally. In the mainstream setting, exposure avoidance strategies aimed to reduce the incidence of ONIHL remain the focus of public health and occupational medicine approaches[2]. In military conditions this is most often caused by such things as explosions, blasts, or loud noises from vehicles ranging from 100 to 140 dB[3] and military weapons generating approximately 140-185 dB peak sound pressure levels[4].

  16. Blast noise classification with common sound level meter metrics.

    Science.gov (United States)

    Cvengros, Robert M; Valente, Dan; Nykaza, Edward T; Vipperman, Jeffrey S

    2012-08-01

    A common set of signal features measurable by a basic sound level meter are analyzed, and the quality of information carried in subsets of these features are examined for their ability to discriminate military blast and non-blast sounds. The analysis is based on over 120 000 human classified signals compiled from seven different datasets. The study implements linear and Gaussian radial basis function (RBF) support vector machines (SVM) to classify blast sounds. Using the orthogonal centroid dimension reduction technique, intuition is developed about the distribution of blast and non-blast feature vectors in high dimensional space. Recursive feature elimination (SVM-RFE) is then used to eliminate features containing redundant information and rank features according to their ability to separate blasts from non-blasts. Finally, the accuracy of the linear and RBF SVM classifiers is listed for each of the experiments in the dataset, and the weights are given for the linear SVM classifier.

  17. Levels And Spectra Of Aircraft Noise And People\\'s Reactions In ...

    African Journals Online (AJOL)

    A study of sound levels and spectral distribution as well as people\\'s reactions to aircraft noise in three Nigerian international airports have been conducted. The study comprised physical measurements and social survey. Results show that maximum octave band pressure levels (BPLs) for Margaret Ekpo, Port Harcourt and ...

  18. Visual performance in cataract patients with low levels of postoperative astigmatism: full correction versus spherical equivalent correction

    Directory of Open Access Journals (Sweden)

    Lehmann RP

    2012-03-01

    Full Text Available Robert P Lehmann1, Diane M Houtman21Lehmann Eye Center, Nacogdoches, TX, 2Alcon Research Ltd, Fort Worth, TX, USAPurpose: To evaluate whether visual performance could be improved in pseudophakic subjects by correcting low levels of postoperative astigmatism.Methods: An exploratory, noninterventional study was conducted using subjects who had been implanted with an aspheric intraocular lens and had 0.5–0.75 diopter postoperative astigmatism. Monocular visual performance using full correction was compared with visual performance using spherical equivalent correction. Testing consisted of high- and low-contrast visual acuity, contrast sensitivity, and reading acuity and speed using the Radner Reading Charts.Results: Thirty-eight of 40 subjects completed testing. Visual acuities at three contrast levels (100%, 25%, and 9% were significantly better using full correction than when using spherical equivalent correction (all P < 0.001. For contrast sensitivity testing under photopic, mesopic, and mesopic with glare conditions, only one out of twelve outcomes demonstrated a significant improvement with full correction compared with spherical equivalent correction (at six cycles per degree under mesopic without glare conditions, P = 0.046. Mean reading speed was numerically faster with full correction across all print sizes, reaching statistical significance at logarithm of the reading acuity determination (logRAD 0.2, 0.7, and 1.1 (P , 0.05. Statistically significant differences also favored full correction in logRAD score (P = 0.0376, corrected maximum reading speed (P < 0.001, and logarithm of the minimum angle of resolution/logRAD ratio (P < 0.001.Conclusions: In this study of pseudophakic subjects with low levels of postoperative astigmatism, full correction yielded significantly better reading performance and high- and low-contrast visual acuity than spherical equivalent correction, suggesting that cataractous patients may benefit from surgical

  19. Assessment of ambient noise levels in the urban residential streets of Eastern Alexandria, Egypt.

    Science.gov (United States)

    Zaki, Gehan R

    2012-12-01

    Street of Alexandria have numerous unplanned, mixed, and noisy activities that may interfere with public health and comfort. The aim of this study was to assess A-weighted ambient noise levels in urban residential streets of Eastern Alexandria, Egypt, from September 2010 to January 2011, with the objective of recommending corrective actions to minimize high noise levels. A descriptive cross-sectional study was carried out, in which A-weighted ambient noise levels were measured on the basis of 24-h periods, using Ono sokki la-5120--precision integrating sound level meter, from September 2010 to January 2011. The measurements were taken on three streets, which were selected using stratified random sampling. Seven measurement sites, along the three streets under study, were selected by site visits according to predetermined criteria. A-weighted ambient noise levels (LAeq) were the highest [70.7 (24.2) dB] on high-traffic-density and high-human-activity streets followed by streets with moderate and low traffic density and human activity [67.5 (31.3) and 62.8 (38.2) dB], respectively. It varied significantly depending on means of transportation (road traffic, train, and/or tram) and human activities (parking lots, shops, and/or street merchants). The A-weighted ambient noise levels on urban residential streets of Eastern Alexandria, Egypt, exceeded the Egyptian National Standards during the three periods of the day (daytime, evening, and night), except in some relatively quiet locations during the night. Consequently, remedial actions to reduce noise levels were recommended.

  20. Comparison of the Effect of Noise Levels on Stress Response in Two Different Operation Groups in an Orthopedic Surgery Room

    Directory of Open Access Journals (Sweden)

    Hasibe Baytan Yildiz

    2016-09-01

    Full Text Available Aim: The aim of this randomized, single-blinded study was to evaluate the effects of noise on hemodynamic and neuroendocrine stress response by measuring the level of noise in the surgery rooms of patients undergoing knee operations under neuroaxial anesthesia. Gerec ve Yontem: We compared patient responses from two groups of patients: those undergoing knee operations in a surgery room where the noise level (measured in decibels is high, and those undergoing meniscus operations in a surgery room with lower noise levels. The STAI, the State-Trait Anxiety Inventory (STAI-1, and the anxiety test (STAI-2wereperformed at preoperative and postoperative periods. 20 ml of blood sample was taken for basal, intraoperative 30th minute, and postoperative 1st hour measurements. Systolic, diastolic, and mean arterial blood pressures were found to be higher in the high noise level group. ACTH levels were increased during the early postoperative period and became normal during the late postoperative period in the high noise level group whereas ACTH levels were significantly decreased in the low-noise level group. Basal cortisol levels were significantly higher in the high noise level group. HCRP, an inflammatory response mediator was found to be decreased in both groups. Early and late blood glucose levels were significantly higher in the high noise group. There was a greater increase in early and late blood glucose levels in the high noise group. In the postoperative period, although the state-trait anxiety inventory (STAI-2 levels being higher in patients subject to noisier environment determines how people feel independent of the conditions and state they are in, this result made us consider that the noise the patients were subjected to in the intraoperative period may cause a stress response. Discussion: As a result we believe that standard noise levels should be achieved by reducing the factors causing high noise levels in the operating room. This will

  1. Noise level in intensive care units of a public university hospital in Santa Marta (Colombia).

    Science.gov (United States)

    Garrido Galindo, A P; Camargo Caicedo, Y; Vélez-Pereira, A M

    2016-10-01

    To evaluate the noise level in adult, pediatric and neonatal intensive care units of a university hospital in the city of Santa Marta (Colombia). A descriptive, observational, non-interventional study with follow-up over time was carried out. Continuous sampling was conducted for 20 days for each unit using a type i sound level meter, filter frequency in A weighting and Fast mode. We recorded the maximum values, the 90th percentile as background noise, and the continuous noise level. The mean hourly levels in the adult unit varied between 57.40±1.14-63.47±2.13dBA, with a maximum between 71.55±2.32-77.22±1.94dBA, and a background noise between 53.51±1.16-60.26±2.10dBA; in the pediatric unit the mean hourly levels varied between 57.07±3.07-65.72±2.46dBA, with a maximum of 68.69±3.57-79.06±2.34dBA, and a background noise between 53.33±3.54-61.96±2.85dBA; the neonatal unit in turn presented mean hourly values between 59.54±2.41-65.33±1.77dBA, with a maximum value between 67.20±2.13-77.65±3.74dBA, and a background noise between 55.02±2.03-58.70±1.95dBA. Analysis of variance revealed a significant difference between the hourly values and between the different units, with the time of day exhibiting a greater influence. The type of unit affects the noise levels in intensive care units, the pediatric unit showing the highest values and the adult unit the lowest values. However, the parameter exerting the greatest influence upon noise level is the time of day, with higher levels in the morning and evening, and lower levels at night and in the early morning. Copyright © 2015 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  2. Sea-Level Trend Uncertainty With Pacific Climatic Variability and Temporally-Correlated Noise

    Science.gov (United States)

    Royston, Sam; Watson, Christopher S.; Legrésy, Benoît; King, Matt A.; Church, John A.; Bos, Machiel S.

    2018-03-01

    Recent studies have identified climatic drivers of the east-west see-saw of Pacific Ocean satellite altimetry era sea level trends and a number of sea-level trend and acceleration assessments attempt to account for this. We investigate the effect of Pacific climate variability, together with temporally-correlated noise, on linear trend error estimates and determine new time-of-emergence (ToE) estimates across the Indian and Pacific Oceans. Sea-level trend studies often advocate the use of auto-regressive (AR) noise models to adequately assess formal uncertainties, yet sea level often exhibits colored but non-AR(1) noise. Standard error estimates are over- or under-estimated by an AR(1) model for much of the Indo-Pacific sea level. Allowing for PDO and ENSO variability in the trend estimate only reduces standard errors across the tropics and we find noise characteristics are largely unaffected. Of importance for trend and acceleration detection studies, formal error estimates remain on average up to 1.6 times those from an AR(1) model for long-duration tide gauge data. There is an even chance that the observed trend from the satellite altimetry era exceeds the noise in patches of the tropical Pacific and Indian Oceans and the south-west and north-east Pacific gyres. By including climate indices in the trend analysis, the time it takes for the observed linear sea-level trend to emerge from the noise reduces by up to 2 decades.

  3. The Relationship between Personality Type and Acceptable Noise Levels: A Pilot Study.

    Science.gov (United States)

    Franklin, Cliff; Johnson, Laura V; White, Letitia; Franklin, Clay; Smith-Olinde, Laura

    2013-01-01

    Objectives. This study examined the relationship between acceptable noise level (ANL) and personality. ANL is the difference between a person's most comfortable level for speech and the loudest level of background noise they are willing to accept while listening to speech. Design. Forty young adults with normal hearing participated. ANLs were measured and two personality tests (Big Five Inventory, Myers-Briggs Type Indicator) were administered. Results. The analysis revealed a correlation between ANL and the openness and conscientious personality dimensions from the Big Five Inventory; no correlation emerged between ANL and the Myers-Briggs personality types. Conclusions. Lower ANLs are correlated with full-time hearing aid use and the openness personality dimension; higher ANLs are correlated with part-time or hearing aid nonuse and the conscientious personality dimension. Current data suggest that those more open to new experiences may accept more noise and possibly be good hearing aid candidates, while those more conscientious may accept less noise and reject hearing aids, based on their unwillingness to accept background noise. Knowing something about a person's personality type may help audiologists determine if their patients will likely be good candidates for hearing aids.

  4. A direct method for calculating instrument noise levels in side-by-side seismometer evaluations

    Science.gov (United States)

    Holcomb, L. Gary

    1989-01-01

    The subject of determining the inherent system noise levels present in modem broadband closed loop seismic sensors has been an evolving topic ever since closed loop systems became available. Closed loop systems are unique in that the system noise can not be determined via a blocked mass test as in older conventional open loop seismic sensors. Instead, most investigators have resorted to performing measurements on two or more systems operating in close proximity to one another and to analyzing the outputs of these systems with respect to one another to ascertain their relative noise levels.The analysis of side-by-side relative performance is inherently dependent on the accuracy of the mathematical modeling of the test configuration. This report presents a direct approach to extracting the system noise levels of two linear systems with a common coherent input signal. The mathematical solution to the problem is incredibly simple; however the practical application of the method encounters some difficulties. Examples of expected accuracies are presented as derived by simulating real systems performance using computer generated random noise. In addition, examples of the performance of the method when applied to real experimental test data are shown.

  5. Noise level estimation in weakly nonlinear slowly time-varying systems

    International Nuclear Information System (INIS)

    Aerts, J R M; Dirckx, J J J; Lataire, J; Pintelon, R

    2008-01-01

    Recently, a method using multisine excitation was proposed for estimating the frequency response, the nonlinear distortions and the disturbing noise of weakly nonlinear time-invariant systems. This method has been demonstrated on the measurement of nonlinear distortions in the vibration of acoustically driven systems such as a latex membrane, which is a good example of a time-invariant system [1]. However, not all systems are perfectly time invariant, e.g. biomechanical systems. This time variation can be misinterpreted as an elevated noise floor, and the classical noise estimation method gives a wrong result. Two improved methods to retrieve the correct noise information from the measurements are presented. Both of them make use of multisine excitations. First, it is demonstrated that the improved methods give the same result as the classical noise estimation method when applied to a time-invariant system (high-quality microphone membrane). Next, it is demonstrated that the new methods clearly give an improved estimate of the noise level on time-varying systems. As an application example results for the vibration response of an eardrum are shown

  6. Noise Pollution and Health Effects

    Directory of Open Access Journals (Sweden)

    Geravandi

    2015-01-01

    Full Text Available Background Noise pollution is of particular importance due to the physical and psychological effects on humans. Noise is a stressor that affects the autonomic nervous system and the endocrine system. Noise is also a threat to marine and terrestrial ecosystems. Health risks from noise are correlated with road traffic. In other words, noise health effects are the health consequences of elevated sound levels. Objectives This study aims to determine the effect of noise pollution (near roadways on health issues in Ahvaz, Iran. Materials and Methods In this cross-sectional study, equivalent sound pressure level were measured by sound level meters TES-1353 in 75 locations around 4 roadways, which had a high load of traffic in Ahvaz City during day time. During the study, 820 measurements were recorded at measuring stations, for 7 days per week with 1-hour interval between each measurement. Statistical analysis was carried out by SPSS software. Results According to the research findings, the equivalent sound pressure levels in all stations were 76.28 ± 3.12 dB (Mean ± SD. According to sound measurements and the survey questionnaire, noise pollution is higher than EPA (US Environmental Protection Agency and Iran standard level. Based on result of this study the worst noise health effects were the nervousness and sleep quality during 2012. Conclusions According to the results of this study, with increasing load of traffic, there is an increasing need for proper consideration plans to control noise pollution and prevent its effects.

  7. Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?

    Directory of Open Access Journals (Sweden)

    Małgorzata Pawlaczyk-Łuszczyńska

    2016-06-01

    Full Text Available Background: The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL. Material and Methods: Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20–57 years, directly employed in the manufacture of furniture. The actual workers’ hearing threshold levels (HTLs were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Results: Workers under study were exposed to noise at daily noise exposure levels of 82.7–94.8 dB (mean: 90.9 dB for a period of 3–14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers’ HTLs at 3000–6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg and lower (≤ 78 mm Hg diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. Conclusions: The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3:337–351

  8. [Do hearing threshold levels in workers of the furniture industry reflect their exposure to noise?].

    Science.gov (United States)

    Pawlaczyk-Łuszczyńska, Małgorzata; Dudarewicz, Adam; Czaja, Norman; Bortkiewicz, Alicja

    The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL). Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20-57 years, directly employed in the manufacture of furniture. The actual workers' hearing threshold levels (HTLs) were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Workers under study were exposed to noise at daily noise exposure levels of 82.7-94.8 dB (mean: 90.9 dB) for a period of 3-14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers' HTLs at 3000-6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg) and lower (≤ 78 mm Hg) diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3):337-351. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  9. 36 CFR 3.15 - What is the maximum noise level for the operation of a vessel?

    Science.gov (United States)

    2010-07-01

    ... level for the operation of a vessel? 3.15 Section 3.15 Parks, Forests, and Public Property NATIONAL PARK... level for the operation of a vessel? (a) A person may not operate a vessel at a noise level exceeding... vessel is being operated in excess of the noise levels established in paragraph (a) of this section may...

  10. Noise level in a neonatal intensive care unit in Santa Marta - Colombia.

    Science.gov (United States)

    Garrido Galindo, Angélica Patricia; Camargo Caicedo, Yiniva; Velez-Pereira, Andres M

    2017-09-30

    The environment of neonatal intensive care units is influenced by numerous sources of noise emission, which contribute to raise the noise levels, and may cause hearing impairment and other physiological and psychological changes on the newborn, as well as problems with care staff. To evaluate the level and sources of noise in the neonatal intensive care unit. Sampled for 20 consecutive days every 60 seconds in A-weighting curves and fast mode with a Type I sound level meter. Recorded the average, maximum and minimum, and the 10th, 50th and 90th percentiles. The values are integrated into hours and work shift, and studied by analysis of variance. The sources were characterized in thirds of octaves. The average level was 64.00 ±3.62 dB(A), with maximum of 76.04 ±5.73 dB(A), minimum of 54.84 ±2.61dB(A), and background noise of 57.95 ±2.83 dB(A). We found four sources with levels between 16.8-63.3 dB(A). Statistical analysis showed significant differences between the hours and work shift, with higher values in the early hours of the day. The values presented exceed the standards suggested by several organizations. The sources identified and measured recorded high values in low frequencies.

  11. BAYESIAN ANALYSIS OF WHITE NOISE LEVELS IN THE FIVE-YEAR WMAP DATA

    International Nuclear Information System (INIS)

    Groeneboom, N. E.; Eriksen, H. K.; Gorski, K.; Huey, G.; Jewell, J.; Wandelt, B.

    2009-01-01

    We develop a new Bayesian method for estimating white noise levels in CMB sky maps, and apply this algorithm to the five-year Wilkinson Microwave Anisotropy Probe (WMAP) data. We assume that the amplitude of the noise rms is scaled by a constant value, α, relative to a pre-specified noise level. We then derive the corresponding conditional density, P(α | s, C l , d), which is subsequently integrated into a general CMB Gibbs sampler. We first verify our code by analyzing simulated data sets, and then apply the framework to the WMAP data. For the foreground-reduced five-year WMAP sky maps and the nominal noise levels initially provided in the five-year data release, we find that the posterior means typically range between α = 1.005 ± 0.001 and α = 1.010 ± 0.001 depending on differencing assembly, indicating that the noise level of these maps are biased low by 0.5%-1.0%. The same problem is not observed for the uncorrected WMAP sky maps. After the preprint version of this letter appeared on astro-ph., the WMAP team has corrected the values presented on their web page, noting that the initially provided values were in fact estimates from the three-year data release, not from the five-year estimates. However, internally in their five-year analysis the correct noise values were used, and no cosmological results are therefore compromised by this error. Thus, our method has already been demonstrated in practice to be both useful and accurate.

  12. Relationship between Lighting and Noise Levels and Productivity of the Occupants in Automotive Assembly Industry

    Directory of Open Access Journals (Sweden)

    Jafar Akbari

    2013-01-01

    Full Text Available Work environment affects human productivity and his performance. The aims of this study were to investigate the effects of lighting and noise levels on human productivity in the automotive assembly industry. Method. Subjects were 181 workers from different parts of an automobile assembly industry. Illuminance (Lx at the height of 30 inches from the surface of work station and noise (dBA were locally measured. Also human productivity by the Goldsmith and Hersey scale (1980 was measured. Data were analyzed by using SPSS v20 Pearson correlation coefficient. Results. The results showed that the relationship between noise level and human productivity is negative and significant (, , but there was no significant relationship between lighting and human productivity (. Conclusion. Based on the results, in assembly tasks, noise has a negative impact on human productivity, and lighting does not affect this. So, in order to increase employee productivity, noise control and reduction to less than the standard values (less than 85 dB is necessary.

  13. Noise levels of toys for children between the ages of birth and 3 ...

    African Journals Online (AJOL)

    Design. A quantitative, non-experimental, descriptive research design was employed for this study. Subjects. Twenty toys, 5 from each of 4 categories, were chosen from a popular toy store in ... the noise levels of toys on the packaging and adherence to ASTM International standards for toy manufacturers are recommended.

  14. Noise levels of toys for children between the ages of birth and 3 ...

    African Journals Online (AJOL)

    Noise-induced hearing loss (NIHL) in children is a growing area of concern for ... Sound intensity or loudness, measured as sound pressure level (SPL) in a logarithmic decibel ..... Focus needs to be placed on increasing parents' awareness of ...

  15. The measurement equivalence of Big Five factor markers for persons with different levels of education.

    Science.gov (United States)

    Rammstedt, Beatrice; Goldberg, Lewis R; Borg, Ingwer

    2010-02-01

    Previous findings suggest that the Big-Five factor structure is not guaranteed in samples with lower educational levels. The present study investigates the Big-Five factor structure in two large samples representative of the German adult population. In both samples, the Big-Five factor structure emerged only in a blurry way at lower educational levels, whereas for highly educated persons it emerged with textbook-like clarity. Because well-educated persons are most comparable to the usual subjects of psychological research, it might be asked if the Big Five are limited to such persons. Our data contradict this conclusion. There are strong individual differences in acquiescence response tendencies among less highly educated persons. After controlling for this bias the Big-Five model holds at all educational levels.

  16. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    Science.gov (United States)

    Urbanowicz, Krzysztof; Hołyst, Janusz A.

    2004-12-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse-grained entropy, we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40% to 80% of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that the implementation of a corresponding threshold investment strategy leads to positive returns for historical data.

  17. Effect of external pressure environment on the internal noise level due to a source inside a cylindrical tank

    Science.gov (United States)

    Clevenson, S. A.; Roussos, L. A.

    1984-01-01

    A small cylindrical tank was used to study the effect on the noise environment within a tank of conditions of atmospheric (sea level) pressure or vacuum environments on the exterior. Experimentally determined absorption coefficients were used to calculate transmission loss, transmissibility coefficients and the sound pressure (noise) level differences in the interior. The noise level differences were also measured directly for the two exterior environments and compared to various analytical approximations with limited agreement. Trend study curves indicated that if the tank transmission loss is above 25 dB, the difference in interior noise level between the vacuum and ambient pressure conditions are less than 2 dB.

  18. Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

    OpenAIRE

    Krzysztof Urbanowicz; Janusz A. Holyst

    2004-01-01

    Using a recently developed method of noise level estimation that makes use of properties of the coarse grained-entropy we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40 to 80 percent of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that implementation of a corresponding threshold investment stra...

  19. Equivalent threshold sound pressure levels for acoustic test signals of short duration

    DEFF Research Database (Denmark)

    Poulsen, Torben; Daugaard, Carsten

    1998-01-01

    . The measurements were performed with two types of headphones, Telephonics TDH-39 and Sennheiser HDA-200. The sound pressure levels were measured in an IEC 318 ear simulator with Type 1 adapter (a flat plate) and a conical ring. The audiometric methods used in the experiments were the ascending method (ISO 8253...

  20. Reducing visitor noise levels at Muir Woods National Monument using experimental management.

    Science.gov (United States)

    Stack, David W; Peter, Newman; Manning, Robert E; Fristrup, Kurt M

    2011-03-01

    Noise impacts resources and visitor experience in many protected natural areas, and visitors can be the dominant source of noise. This experimental study tested the efficacy and acceptability of signs asking visitors to be quiet at Muir Woods National Monument, California. Signs declaring a "quiet zone" (at the park's Cathedral Grove) or a "quiet day" (throughout the park) were posted on a randomized schedule that included control days (no signs). Visitor surveys were conducted to measure the cognitive and behavioral responses of visitors to the signs and test the acceptability of these management practices to visitors. Visitors were highly supportive of these management practices and reported that they consciously limited the amount of noise they produced. Sound level measurements showed substantial decreases on days when signs were posted. © 2011 Acoustical Society of America

  1. In vitro comparison of noise levels produced by different CPAP generators.

    Science.gov (United States)

    Kirchner, Lieselotte; Wald, Martin; Jeitler, Valerie; Pollak, Arnold

    2012-01-01

    Minimization of noise exposure is an important aim of modern neonatal intensive care medicine. Binasal continuous positive airway pressure (CPAP) generators are among the most important sources of continuous noise in neonatal wards. The aim of this study was to find out which CPAP generator creates the least noise. In an experimental setup, two jet CPAP generators (Infant Flow® generator and MediJet®) and two conventional CPAP generators (Bubble CPAP® and Baby Flow®) were compared. Noise production was measured in decibels in an A-weighted scale [dB(A)] in a closed incubator at 2 mm lateral distance from the end of the nasal prongs. Reproduction of constant airway pressure and air leak was achieved by closure of the nasal prongs with a type of adhesive tape that is semipermeable to air. The noise levels produced by the four generators were significantly different (p CPAP® and 55 dB(A) for the Baby Flow®. Conventional CPAP generators work more quietly than the currently available jet CPAP generators. Copyright © 2011 S. Karger AG, Basel.

  2. High levels of sound pressure: acoustic reflex thresholds and auditory complaints of workers with noise exposure

    Directory of Open Access Journals (Sweden)

    Alexandre Scalli Mathias Duarte

    2015-08-01

    Full Text Available INTRODUCTION: The clinical evaluation of subjects with occupational noise exposure has been difficult due to the discrepancy between auditory complaints and auditory test results. This study aimed to evaluate the contralateral acoustic reflex thresholds of workers exposed to high levels of noise, and to compare these results to the subjects' auditory complaints.METHODS: This clinical retrospective study evaluated 364 workers between 1998 and 2005; their contralateral acoustic reflexes were compared to auditory complaints, age, and noise exposure time by chi-squared, Fisher's, and Spearman's tests.RESULTS: The workers' age ranged from 18 to 50 years (mean = 39.6, and noise exposure time from one to 38 years (mean = 17.3. We found that 15.1% (55 of the workers had bilateral hearing loss, 38.5% (140 had bilateral tinnitus, 52.8% (192 had abnormal sensitivity to loud sounds, and 47.2% (172 had speech recognition impairment. The variables hearing loss, speech recognition impairment, tinnitus, age group, and noise exposure time did not show relationship with acoustic reflex thresholds; however, all complaints demonstrated a statistically significant relationship with Metz recruitment at 3000 and 4000 Hz bilaterally.CONCLUSION: There was no significance relationship between auditory complaints and acoustic reflexes.

  3. Effects of venting on wind noise levels measured at the eardrum.

    Science.gov (United States)

    Chung, King

    2013-01-01

    Wind noise can be a nuisance to hearing aid users. With the advent of sophisticated feedback reduction algorithms, people with higher degrees of hearing loss are fit with larger vents than previously allowed, and more people with lesser degrees of hearing loss are fit with open hearing aids. The purpose of this study was to examine the effects of venting on wind noise levels in the ear canal for hearing aids with omnidirectional and directional microphones. Two behind-the-ear hearing aids were programmed when they were worn on a Knowles Electronics Manikin for Acoustic Research. The hearing aid worn on the right ear was programmed to the omnidirectional microphone mode and the one on the left to the directional microphone mode. The hearing aids were adjusted to linear amplification with flat frequency response in an anechoic chamber. Gains below 10 dB were used to avoid output limiting of wind noise levels at low input levels. Wind noise samples were recorded at the eardrum location in a wind tunnel at wind velocities ranging from a gentle to a strong breeze. The hearing aids were coupled to #13 tubings (i.e., open vent), or conventional skeleton earmolds with no vent, pressure vents, or 3mm vents. Polar and spectral characteristics of wind noise were analyzed off-line using MatLab programs. Wind noise levels in the ear canals were mostly predicted by vent-induced frequency response changes in the conventional earmold conditions for both omnidirectional and directional hearing aids. The open vent condition, however, yielded the lowest levels, which could not be entirely predicted by the frequency response changes of the hearing aids. This indicated that a wind-related vent effect permitted an additional amount of sound reduction in the ear canal, which could not be explained by known vent effects. For the microphone location, form factor, and gain settings tested, open fit hearing aids yielded lower noise levels at the eardrum location than conventional behind

  4. Listening level of music through headphones in train car noise environments.

    Science.gov (United States)

    Shimokura, Ryota; Soeta, Yoshiharu

    2012-09-01

    Although portable music devices are useful for passing time on trains, exposure to music using headphones for long periods carries the risk of damaging hearing acuity. The aim of this study is to examine the listening level of music through headphones in the noisy environment of a train car. Eight subjects adjusted the volume to an optimum level (L(music)) in a simulated noisy train car environment. In Experiment I, the effects of noise level (L(train)) and type of train noise (rolling, squealing, impact, and resonance) were examined. Spectral and temporal characteristics were found to be different according to the train noise type. In Experiment II, the effects of L(train) and type of music (five vocal and five instrumental music) were examined. Each music type had a different pitch strength and spectral centroid, and each was evaluated by φ(1) and W(φ(0)), respectively. These were classified as factors of the autocorrelation function (ACF) of the music. Results showed that L(music) increased as L(train) increased in both experiments, while the type of music greatly influenced L(music). The type of train noise, however, only slightly influenced L(music). L(music) can be estimated using L(train) and the ACF factors φ(1) and W(φ(0)).

  5. Alternatives to dose, quality factor and dose equivalent for low level irradiation

    International Nuclear Information System (INIS)

    Sondhaus, C.A.; Bond, V.P.; Feinendegen, L.E.

    1988-01-01

    Randomly occurring energy deposition events produced by low levels of ionizing radiation interacting with tissue deliver variable amounts of energy to the sensitive target volumes within a small fraction of the cell population. A model is described in which an experimentally derived function relating event size to cell response probability operates mathematically on the microdosimetric event size distribution characterizing a given irradiation and thus determines the total fractional number of responding cells; this fraction measures the effectiveness of the given radiation. Normalizing to equal numbers of events produced by different radiations and applying this cell response or hit size effectiveness function (HSEF) should define radiation quality, or relative effectiveness, on a more nearly absolute basis than do the absorbed dose and dose evaluation, which are confounded when applied to low level irradiations. Examples using both calculation and experimental data are presented. 15 refs., 18 figs

  6. A Comparative Land Use-Based Analysis of Noise Pollution Levels in Selected Urban Centers of Nigeria.

    Science.gov (United States)

    Baloye, David O; Palamuleni, Lobina G

    2015-09-29

    Growth in the commercialization, mobility and urbanization of human settlements across the globe has greatly exposed world urban population to potentially harmful noise levels. The situation is more disturbing in developing countries like Nigeria, where there are no sacrosanct noise laws and regulations. This study characterized noise pollution levels in Ibadan and Ile-Ife, two urban areas of Southwestern Nigeria that have experienced significant increases in population and land use activities. Eight hundred noise measurements, taken at 20 different positions in the morning, afternoon, and evening of carefully selected weekdays, in each urban area, were used for this study. Findings put the average noise levels in the urban centers at between 53 dB(A) and 89 dB (A), a far cry from the World Health Organization (WHO) permissible limits in all the land use types, with highest noise pollution levels recorded for transportation, commercial, residential and educational land use types. The result of the one-way ANOVA test carried out on the dependent variable noise and fixed factor land use types reveals a statistically significant mean noise levels across the study area (F(3,34) = 15.13, p = 0.000). The study underscores noise pollution monitoring and the urgent need to control urban noise pollution with appropriate and effective policies.

  7. A Survey of the Relationship Between Noised Pollution, Honey and Vitamin E and Plasma Level of Blood Sexual Hormones in Noise-Exposed Rats

    Directory of Open Access Journals (Sweden)

    Kenani

    2015-02-01

    Full Text Available Background This study was conducted to examine the efficacy of honey and vitamin E on fertilization capacity of noise-exposed rats by assessing whether the plasma sexual hormones levels i.e. follicle stimulating hormone (FSH, luteinizing hormone (LH and testosterone are altered in relation with noise stress. Objectives Therefore, this study aimed to evaluate the effects of honey and vitamin E on the levels of sex hormones and male fertilization capacity of noise-exposed rats. Materials and Methods This study targeted 24 male rats that were randomly divided into four equal groups including the control group that were not exposed to noise and experimental groups 1, 2 and 3 that were the untreated, honey treated and vitamin E treated groups, respectively; all of which were exposed to noise for 50 days. Next, in order to measure serum sexual hormones, blood samples of experimental and control groups were taken and analyzed. Also in order to investigate the fertility capacity of rats, the male rats of all groups were coupled with female rats. Results The results showed that in the male rats exposed to the noise stress, the levels of FSH and LH rose and the testosterone secretion fell sharply compared to not exposed rats. Additionally, the continuing effects of noise stress injury could reduce the weight of the fetus and the number of live fetuses and survival rate of the fetus. However, honey and vitamin E improved serum testosterone concentration, while declined plasma FSH and LH secretion in noise-exposed rats and enhanced fertility rate by increasing the rate of healthy alive fetuses. Conclusions It seems that noise pollution has harmful effects on the fertility of males. Also these findings may suggest the use of a natural curative approach rather than pharmaceutical drugs to optimize both neuroendocrine gonadal axis and testicular integrity induced by pathogenesis stress, and enhance fertility capacity in men.

  8. Hearing impairment among workers exposed to excessive levels of noise in ginning industries

    Directory of Open Access Journals (Sweden)

    Kamalesh J Dube

    2011-01-01

    Full Text Available Cotton ginning workers have a risk of hearing loss due to excessive noise levels at the workplace environment. In this study, estimates of typical sound levels prevailing at the workplace environment and its effects on hearing ability of the exposed workers were made among cotton ginning workers. Data on self-reported health status was collected by a questionnaire survey at 10 cotton ginning industries located at Jalgaon district of Maharashtra state, India. The cotton ginning workers were exposed to continuous noise levels between 89 and 106 dBA. The hearing ability of the subjects was accessed by pure tone audiometry. The results of audiometry show mild, moderate and moderately severe degree of hearing impairment among the cotton ginning workers. The data generated during the study show that hearing loss was significantly associated with period of exposure to the workplace noise (P <0.0001. The prevalence of audiometric hearing impairment defined as a threshold average greater than 25 dB hearing level was 96% for binaural low-frequency average, 97% for binaural mid frequency average and 94% for binaural high-frequency average in the cotton ginning workers. We recommend the compulsory use of personal protective equipment like ear plug by the cotton ginning workers at the workplace environment. A regular maintenance of ginning and pressing machineries will avoid the emission of excessive noise at the workplace environment of cotton gins. A regular periodic medical examination is necessary to measure the impact of workplace noise on the health of cotton ginning workers.

  9. The Effect of the Cholesterol Levels on Noise-Induced Hearing Loss.

    Science.gov (United States)

    Demir, Mehmet Gokhan; Aydin, Sedat

    2018-01-01

    Introduction  Noise-induced hearing loss (NIHL), which is one of the most common occupational diseases among industrialized populations, is associated with longstanding exposure to high levels of noise. The pathogenesis of NIHL is not clear, but some genes and their activity at the tissue level have been investigated. Hypercholesterolemia, which can disturb the microcirculation, can be one of the underlying pathologies in hearing loss. Objective  To investigate the relationship between NIHL and hypercholesterolemia. Methods  The study group was selected among workers who had an occupational exposure of 85 dB of noise for at least 10 years. The audiologic assessment was recorded at seven frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 3,000 Hz, 4,000 Hz, 6,000 Hz and 8,000 Hz). A total of 456 workers were included in the study and divided into two groups: the control group (252 patients) and the NIHL group (204 patients). After the audiologic measurement, blood samples were taken and investigated for blood cholesterol levels. According to these results, the groups were compared. Results  Both groups were similarly distributed regarding age and occupational exposure time ( p  > 0.05). We could not detect any association between cholesterol levels and noise-induced hearing loss ( p   0.05). Conclusion  Noise-induced hearing loss is still a common occupational problem that can be prevented by hearing conservation programs and occupational health and safety training. Still, we know little about the relationship between NIHL and hypercholesterolemia. According to our findings, we cannot detect any relationship. Controlled studies and studies with human individuals can be made possible in the future with diagnostic innovations in tissue imaging and tissue microcircular sampling.

  10. Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

    DEFF Research Database (Denmark)

    Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen

    2017-01-01

    Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12...... complements the existing model presented by Pelegrín-García, Smits, Brunskog, and Jeong (2011) and expands on it by taking into account the effects of occlusion and background noise level on changes in speech sound level. Conclusions: Three models of the relationship between vocal effort, background noise...

  11. Assessment and analysis of noise levels in and around Ib river coalfield, Orissa, India.

    Science.gov (United States)

    Mohapatra, Haraprasad; Goswami, Shreerup

    2012-05-01

    Heavy earth moving machineries, different capacities of dumpers and loaders, blasting and drilling make the mining environment noisy. A study was carried out to assess the noise level in different opencast projects in and around Belpahar and Brajarajnagar areas of Ib river coalfield. Noise assessment was carried out in various residential, commercial and industrial places. The noise levels, especially L(eq) values of different wheel loaders, dumpers, shovel and crusher units were also assessed and were more than permissible limit (90dB) in some of their operating conditions. Sound ressure level measurements while drilling into coal and overburden at Lakhanpur opencast project yielded noise levels (L(eq)) of 81.33 to 96.2 dB. Thus, these L(eq) values of drilling machines in most of the operating conditions were above permissible limit. The average noise intensities (6 a.m.-10 p.m.: 51.6-60.875dB and 10 p.m.-6 a.m.: 42.6-49.8dB) and L(eq) values (6 a.m.-10 p.m.: 50.9-67.0dB and 10 p.m.-6 a.m.: 40.8-53.3dB) during both day and night time of the residential areas around the Ib river coalfield were in close proximity or beyond the permissible limit. The L(eq) values at some of the commercial and industrial places were beyond (6 a.m.-10 p.m.: 61.6-88.3 dB and 10 p.m.-6 a.m.: 55.4-64.8dB) permissible limit. However, in most of the cases, the L(max) noise values were more (6 a.m.-10 p.m.: 68.5-91.4 dB and 10 p.m.-6 a.m.: 69.3-76.4dB) than the permissible limit. Analysis of variance was also computed for heavy earth moving machineries in different operating conditions and also for different residential, commercial and industrial places to infer the level of significance. The difference of noise intensity produced by different wheel loaders at Lakhanpur and Lilari opencast projects, drilling machines at Lakhanpur opencast project, 50 tons capacity dumpers at various conditions of Ib river coalfield within the same operating condition was significant at both 5% and 1% levels

  12. The effects of noise-bandwidth, noise-fringe duration, and temporal signal location on the binaural masking-level difference.

    Science.gov (United States)

    Yasin, Ifat; Henning, G Bruce

    2012-07-01

    The effects of forward and backward noise fringes on binaural signal detectability were investigated. Masked thresholds for a 12-ms, 250-Hz, sinusoidal signal masked by Gaussian noise, centered at 250 Hz, with bandwidths from 3 to 201 Hz, were obtained in N(0)S(0) and N(0)S(π) configurations. The signal was (a) temporally centered in a 12-ms noise burst (no fringe), (b) presented at the start of a 600-ms noise burst (backward fringe), or (c) temporally centered in a 600-ms noise burst (forward-plus-backward fringe). For noise bandwidths between 3 and 75 Hz, detection in N(0)S(0) improved with the addition of a backward fringe, improving further with an additional forward fringe; there was little improvement in N(0)S(π). The binaural masking-level difference (BMLD) increased from 0 to 8 dB with a forward-plus-backward fringe as noise bandwidths increased to 100 Hz, increasing slightly to 10 dB at 201 Hz. This two-stage increase was less pronounced with a backward fringe. With no fringe, the BMLD was about 10-14 dB at all bandwidths. Performance appears to result from the interaction of across-time and across-frequency listening strategies and the possible effects of gain reduction and suppression, which combine in complex ways. Current binaural models are, as yet, unable to account fully for these effects.

  13. High-fructose corn syrup and sucrose have equivalent effects on energy-regulating hormones at normal human consumption levels.

    Science.gov (United States)

    Yu, Zhiping; Lowndes, Joshua; Rippe, James

    2013-12-01

    Intake of high-fructose corn syrup (HFCS) has been suggested to contribute to the increased prevalence of obesity, whereas a number of studies and organizations have reported metabolic equivalence between HFCS and sucrose. We hypothesized that HFCS and sucrose would have similar effects on energy-regulating hormones and metabolic substrates at normal levels of human consumption and that these values would not change over a 10-week, free-living period at these consumption levels. This was a randomized, prospective, double-blind, parallel group study in which 138 adult men and women consumed 10 weeks of low-fat milk sweetened with either HFCS or sucrose at levels of the 25th, 50th, and 90th percentile population consumption of fructose (the equivalent of 40, 90, or 150 g of sugar per day in a 2000-kcal diet). Before and after the 10-week intervention, 24-hour blood samples were collected. The area under the curve (AUC) for glucose, insulin, leptin, active ghrelin, triglyceride, and uric acid was measured. There were no group differences at baseline or posttesting for all outcomes (interaction, P > .05). The AUC response of glucose, active ghrelin, and uric acid did not change between baseline and posttesting (P > .05), whereas the AUC response of insulin (P < .05), leptin (P < .001), and triglyceride (P < .01) increased over the course of the intervention when the 6 groups were averaged. We conclude that there are no differences in the metabolic effects of HFCS and sucrose when compared at low, medium, and high levels of consumption. © 2013 Elsevier Inc. All rights reserved.

  14. Estimation of background noise level on seismic station using statistical analysis for improved analysis accuracy

    Science.gov (United States)

    Han, S. M.; Hahm, I.

    2015-12-01

    We evaluated the background noise level of seismic stations in order to collect the observation data of high quality and produce accurate seismic information. Determining of the background noise level was used PSD (Power Spectral Density) method by McNamara and Buland (2004) in this study. This method that used long-term data is influenced by not only innate electronic noise of sensor and a pulse wave resulting from stabilizing but also missing data and controlled by the specified frequency which is affected by the irregular signals without site characteristics. It is hard and inefficient to implement process that filters out the abnormal signal within the automated system. To solve these problems, we devised a method for extracting the data which normally distributed with 90 to 99% confidence intervals at each period. The availability of the method was verified using 62-seismic stations with broadband and short-period sensors operated by the KMA (Korea Meteorological Administration). Evaluation standards were NHNM (New High Noise Model) and NLNM (New Low Noise Model) published by the USGS (United States Geological Survey). It was designed based on the western United States. However, Korean Peninsula surrounded by the ocean on three sides has a complicated geological structure and a high population density. So, we re-designed an appropriate model in Korean peninsula by statistically combined result. The important feature is that secondary-microseism peak appeared at a higher frequency band. Acknowledgements: This research was carried out as a part of "Research for the Meteorological and Earthquake Observation Technology and Its Application" supported by the 2015 National Institute of Meteorological Research (NIMR) in the Korea Meteorological Administration.

  15. Prospective cohort study on noise levels in a pediatric cardiac intensive care unit.

    Science.gov (United States)

    Garcia Guerra, Gonzalo; Joffe, Ari R; Sheppard, Cathy; Pugh, Jodie; Moez, Elham Khodayari; Dinu, Irina A; Jou, Hsing; Hartling, Lisa; Vohra, Sunita

    2018-04-01

    To describe noise levels in a pediatric cardiac intensive care unit, and to determine the relationship between sound levels and patient sedation requirements. Prospective observational study at a pediatric cardiac intensive care unit (PCICU). Sound levels were measured continuously in slow A weighted decibels dB(A) with a sound level meter SoundEarPro® during a 4-week period. Sedation requirement was assessed using the number of intermittent (PRNs) doses given per hour. Analysis was conducted with autoregressive moving average models and the Granger test for causality. 39 children were included in the study. The average (SD) sound level in the open area was 59.4 (2.5) dB(A) with a statistically significant but clinically unimportant difference between day/night hours (60.1 vs. 58.6; p-value noise levels were > 90 dB. There was a significant association between average (p-value = 0.030) and peak sound levels (p-value = 0.006), and number of sedation PRNs. Sound levels were above the recommended values with no differences between day/night or open area/single room. High sound levels were significantly associated with sedation requirements. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Background noise levels and correlation with ship traffic in the Gulf of Catania

    Science.gov (United States)

    Viola, Salvatore; Buscaino, Giuseppa; Caruso, Francesco; Chierici, Francesco; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Grammauta, Roasario; Larosa, Giuseppina; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Sciacca, Virginia; Simeone, Francesco; Beranzoli, Laura; Marinaro, Giuditta

    2015-04-01

    In the last decades the growing interest in the evaluation of the underwater acoustic noise for studies in the fields of geology, biology and high-energy physics is driving the scientific community to collaborate towards a multidisciplinary approach to the topic. In June 2012 in the framework of the European project EMSO, a multidisciplinary underwater observatory, named NEMO-SN1, was installed 25 km off-shore the port of Catania, at a depth of 2100 m and operated until May 2013 by INFN (Istituto Nazionale di Fisica Nucleare) and INGV (Istituto Nazionale di Geofisica e Vulcanologia). NEMO-SN1 hosted aboard geophysical, oceanographic and acoustic sensors: among these a seismic hydrophone model SMID DT-405D(V). In this work, conducted within the activity of the SMO project, the results on the evaluation of the underwater acoustic pollution in the Gulf of Catania through SMID DT-405D(V) recordings are presented. The seismic hydrophone provided a data set of about 11 months of continuous (24/7) recordings. Underwater sounds have been continuously digitized at a sampling frequency of 2 kHz and the acquired data have been stored in 10min long files for off-line analysis. To describe one-year background noise levels, the mean integrated acoustic noise was measured every second (sampling frequency 2000, NFFT 2048) in the 1/3 octave bands with centre frequency 63 Hz and for each 10 minutes-long file the 5th, the 50th and the 98th percentiles were calculated. Measured noise was correlated with the shipping traffic in the area, thanks to the data provided by an AIS receiver installed at the INFN-Laboratori Nazionali del Sud. An acoustic noise increment was measured in coincidence with the passing of crafts in the area and it was possible to identify the characteristic spectrum of each ship. A simple model for the estimation of the acoustic noise induced by the ships passing through the area was developed. The model was applied by using AIS data acquired during the operation

  17. The effect of hearing aid signal-processing schemes on acceptable noise levels: perception and prediction.

    Science.gov (United States)

    Wu, Yu-Hsiang; Stangl, Elizabeth

    2013-01-01

    The acceptable noise level (ANL) test determines the maximum noise level that an individual is willing to accept while listening to speech. The first objective of the present study was to systematically investigate the effect of wide dynamic range compression processing (WDRC), and its combined effect with digital noise reduction (DNR) and directional processing (DIR), on ANL. Because ANL represents the lowest signal-to-noise ratio (SNR) that a listener is willing to accept, the second objective was to examine whether the hearing aid output SNR could predict aided ANL across different combinations of hearing aid signal-processing schemes. Twenty-five adults with sensorineural hearing loss participated in the study. ANL was measured monaurally in two unaided and seven aided conditions, in which the status of the hearing aid processing schemes (enabled or disabled) and the location of noise (front or rear) were manipulated. The hearing aid output SNR was measured for each listener in each condition using a phase-inversion technique. The aided ANL was predicted by unaided ANL and hearing aid output SNR, under the assumption that the lowest acceptable SNR at the listener's eardrum is a constant across different ANL test conditions. Study results revealed that, on average, WDRC increased (worsened) ANL by 1.5 dB, while DNR and DIR decreased (improved) ANL by 1.1 and 2.8 dB, respectively. Because the effects of WDRC and DNR on ANL were opposite in direction but similar in magnitude, the ANL of linear/DNR-off was not significantly different from that of WDRC/DNR-on. The results further indicated that the pattern of ANL change across different aided conditions was consistent with the pattern of hearing aid output SNR change created by processing schemes. Compared with linear processing, WDRC creates a noisier sound image and makes listeners less willing to accept noise. However, this negative effect on noise acceptance can be offset by DNR, regardless of microphone mode

  18. Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

    Directory of Open Access Journals (Sweden)

    Wong Jee Keen Raymond

    Full Text Available Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN, Adaptive Neuro-Fuzzy Inference System (ANFIS and Support Vector Machine (SVM. It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

  19. The effect of traffic noise on the hearing level of people on Karachi streets

    International Nuclear Information System (INIS)

    Jawed, I.; Musani, A.; Mahmood, R.; Khambaty, W.Y.; Asim, M.

    2010-01-01

    To study the effects of traffic noise on hearing ability of subjects prone to traffic noise exposure. Method: A hospital based prospective study was performed comprising of 200 selected subjects significantly exposed to traffic noise. These included rickshaw drivers, traffic constables and shopkeepers in central business area. All subjects were questioned according to a Performa after which ENT examination was carried out followed by Pure Tone Audiometer y. Results: Hearing impairment showed correlation with the duration of job when analyzed by linear regression analysis with correlation coefficient r=0.36 (p<0.001), Hearing impairment was 33.81+0.42 dB according to the duration of job (in years). Conclusion: Subjects are perceptually exposed to potentially damaging sound pressure level in the metropolis of Karachi. It was observed that audio logically consistent noise induced hearing loss was found to be 0.42 dB per octave from 500 Hz to 2000 Hz per year of duration of job. (author)

  20. The Cost-Effectiveness of Lowering Permissible Noise Levels Around U.S. Airports

    Directory of Open Access Journals (Sweden)

    Boshen Jiao

    2017-12-01

    Full Text Available Aircraft noise increases the risk of cardiovascular diseases and mental illness. The allowable limit for sound in the vicinity of an airport is 65 decibels (dB averaged over a 24-h ‘day and night’ period (DNL in the United States. We evaluate the trade-off between the cost and the health benefits of changing the regulatory DNL level from 65 dB to 55 dB using a Markov model. The study used LaGuardia Airport (LGA as a case study. In compliance with 55 dB allowable limit of aircraft noise, sound insulation would be required for residential homes within the 55 dB to 65 dB DNL. A Markov model was built to assess the cost-effectiveness of installing sound insulation. One-way sensitivity analyses and Monte Carlo simulation were conducted to test uncertainty of the model. The incremental cost-effectiveness ratio of installing sound insulation for residents exposed to airplane noise from LGA was $11,163/QALY gained (95% credible interval: cost-saving and life-saving to $93,054/QALY gained. Changing the regulatory standard for noise exposure around airports from 65 dB to 55 dB comes at a very good value.

  1. [Relationship between the Mandarin acceptable noise level and the personality traits in normal hearing adults].

    Science.gov (United States)

    Wu, Dan; Chen, Jian-yong; Wang, Shuo; Zhang, Man-hua; Chen, Jing; Li, Yu-ling; Zhang, Hua

    2013-03-01

    To evaluate the relationship between the Mandarin acceptable noise level (ANL) and the personality trait for normal-hearing adults. Eighty-five Mandarin speakers, aged from 21 to 27, participated in this study. ANL materials and the Eysenck Personality Questionnaire (EPQ) questionnaire were used to test the acceptable noise level and the personality trait for normal-hearing subjects. SPSS 17.0 was used to analyze the results. ANL were (7.8 ± 2.9) dB in normal hearing participants. The P and N scores in EPQ were significantly correlated with ANL (r = 0.284 and 0.318, P 0.05). Listeners with higher ANL were more likely to be eccentric, hostile, aggressive, and instabe, no ANL differences were found in listeners who were different in introvert-extravert or lying.

  2. The Usability of Noise Level from Rock Cutting for the Prediction of Physico-Mechanical Properties of Rocks

    Science.gov (United States)

    Delibalta, M. S.; Kahraman, S.; Comakli, R.

    2015-11-01

    Because the indirect tests are easier and cheaper than the direct tests, the prediction of rock properties from the indirect testing methods is important especially for the preliminary investigations. In this study, the predictability of the physico-mechanical rock properties from the noise level measured during cutting rock with diamond saw was investigated. Noise measurement test, uniaxial compressive strength (UCS) test, Brazilian tensile strength (BTS) test, point load strength (Is) test, density test, and porosity test were carried out on 54 different rock types in the laboratory. The results were statistically analyzed to derive estimation equations. Strong correlations between the noise level and the mechanical rock properties were found. The relations follow power functions. Increasing rock strength increases the noise level. Density and porosity also correlated strongly with the noise level. The relations follow linear functions. Increasing density increases the noise level while increasing porosity decreases the noise level. The developed equations are valid for the rocks with a compressive strength below 150 MPa. Concluding remark is that the physico-mechanical rock properties can reliably be estimated from the noise level measured during cutting the rock with diamond saw.

  3. Chronic exposure to low frequency noise at moderate levels causes impaired balance in mice.

    Directory of Open Access Journals (Sweden)

    Haruka Tamura

    Full Text Available We are routinely exposed to low frequency noise (LFN; below 0.5 kHz at moderate levels of 60-70 dB sound pressure level (SPL generated from various sources in occupational and daily environments. LFN has been reported to affect balance in humans. However, there is limited information about the influence of chronic exposure to LFN at moderate levels for balance. In this study, we investigated whether chronic exposure to LFN at a moderate level of 70 dB SPL affects the vestibule, which is one of the organs responsible for balance in mice. Wild-type ICR mice were exposed for 1 month to LFN (0.1 kHz and high frequency noise (HFN; 16 kHz at 70 dB SPL at a distance of approximately 10-20 cm. Behavior analyses including rotarod, beam-crossing and footprint analyses showed impairments of balance in LFN-exposed mice but not in non-exposed mice or HFN-exposed mice. Immunohistochemical analysis showed a decreased number of vestibular hair cells and increased levels of oxidative stress in LFN-exposed mice compared to those in non-exposed mice. Our results suggest that chronic exposure to LFN at moderate levels causes impaired balance involving morphological impairments of the vestibule with enhanced levels of oxidative stress. Thus, the results of this study indicate the importance of considering the risk of chronic exposure to LFN at a moderate level for imbalance.

  4. Modeling Speech Level as a Function of Background Noise Level and Talker-to-Listener Distance for Talkers Wearing Hearing Protection Devices

    Science.gov (United States)

    Bouserhal, Rachel E.; Bockstael, Annelies; MacDonald, Ewen; Falk, Tiago H.; Voix, Jérémie

    2017-01-01

    Purpose: Studying the variations in speech levels with changing background noise level and talker-to-listener distance for talkers wearing hearing protection devices (HPDs) can aid in understanding communication in background noise. Method: Speech was recorded using an intra-aural HPD from 12 different talkers at 5 different distances in 3…

  5. Children's speech recognition and loudness perception with the Desired Sensation Level v5 Quiet and Noise prescriptions.

    Science.gov (United States)

    Crukley, Jeffery; Scollie, Susan D

    2012-12-01

    To determine whether Desired Sensation Level (DSL) v5 Noise is a viable hearing instrument prescriptive algorithm for children, in comparison with DSL v5 Quiet. In particular, the authors compared children's performance on measures of consonant recognition in quiet, sentence recognition in noise, and loudness perception when fitted with DSL v5 Quiet and Noise. Eleven children (ages 8 to 17 years) with stable, congenital sensorineural hearing losses participated in the study. Participants were fitted bilaterally to DSL v5 prescriptions with behind-the-ear hearing instruments. The order of prescription was counterbalanced across participants. Repeated measures analysis of variance was used to compare performance between prescriptions. Use of the Noise prescription resulted in a significant decrease in consonant perception in Quiet with low-level input, but no difference with average-level input. There was no significant difference in sentence-in-noise recognition between the two prescriptions. Loudness ratings for input levels above 72 dB SPL were significantly lower with the noise prescription. Average-level consonant recognition in quiet was preserved and aversive loudness was alleviated by the Noise prescription relative to the quiet prescription, which suggests that the DSL v5 Noise prescription may be an effective approach to managing the nonquiet listening needs of children with hearing loss.

  6. Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Clemens [ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, Brisbane (Australia); Lisenfeld, Juergen [Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe (Germany); Shnirman, Alexander [Institut fuer Theory der Kondensierten Materie, Karlsruhe Institute of Technology, Karlsruhe (Germany); LD Landau Institute for Theoretical Physics, Moscow (Russian Federation); Poletto, Stefano [IBM TJ Watson Research Centre, Yorktown Heights (United States)

    2016-07-01

    Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

  7. Determination of the changes of the plasma catecholamine level by radioenzymatic method following noise-exposition

    International Nuclear Information System (INIS)

    Pinter, Cs.; Vincze, I.

    1982-01-01

    A new method was applied for the determination of plasma catecholamine levels: all the catecholamines were methylated in the presence of S-adenosyl-1-methyl 3 H-methyonine and the radioactivity of the components - separated with thin-layer chromatography - was measured by liquid scintillation. It is concluded that noise exposition for one hour per day significantly increases the plasma concentration of noradrenaline and dopamine whereas the adrenaline-level shows biphasic change: after a short increase it decreases. (L.E.)

  8. Entropy as a measure of the noise extent in a two-level quantum feedback controlled system

    Institute of Scientific and Technical Information of China (English)

    Wang Tao-Bo; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    By introducing the von Neumann entropy as a measure of the extent of noise, this paper discusses the entropy evolution in a two-level quantum feedback controlled system. The results show that the feedback control can induce the reduction of the degree of noise, and different control schemes exhibit different noise controlling ability, the extent of the reduction also related with the position of the target state on the Bloch sphere. It is shown that the evolution of entropy can provide a real time noise observation and a systematic guideline to make reasonable choice of control strategy.

  9. Equivalent circuit-level model of quantum cascade lasers with integrated hot-electron and hot-phonon effects

    Science.gov (United States)

    Yousefvand, H. R.

    2017-12-01

    We report a study of the effects of hot-electron and hot-phonon dynamics on the output characteristics of quantum cascade lasers (QCLs) using an equivalent circuit-level model. The model is developed from the energy balance equation to adopt the electron temperature in the active region levels, the heat transfer equation to include the lattice temperature, the nonequilibrium phonon rate to account for the hot phonon dynamics and simplified two-level rate equations to incorporate the carrier and photon dynamics in the active region. This technique simplifies the description of the electron-phonon interaction in QCLs far from the equilibrium condition. Using the presented model, the steady and transient responses of the QCLs for a wide range of sink temperatures (80 to 320 K) are investigated and analysed. The model enables us to explain the operating characteristics found in QCLs. This predictive model is expected to be applicable to all QCL material systems operating in pulsed and cw regimes.

  10. Estimation of directivity and sound power levels emitted by aircrafts during taxiing, for outdoor noise prediction purpose

    NARCIS (Netherlands)

    Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

    2007-01-01

    Integrated noise model (INM) is the most internationally used software to calculate noise levels near airports. Take off, landing or pass by operations can be modeled by INM, but it does not consider aircrafts taxiing, which, in some cases, can be important to accurately evaluate and reduce

  11. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...... between ANL and outcome of the international outcome inventory for hearing aids (IOI-HA)....

  12. Acceptable noise level (ANL) with Danish and non-semantic speech materials in adult hearing-aid users

    DEFF Research Database (Denmark)

    Olsen, Steen Østergaard; Lantz, Johannes; Nielsen, Lars Holme

    2012-01-01

    The acceptable noise level (ANL) test is used for quantification of the amount of background noise subjects accept when listening to speech. This study investigates Danish hearing-aid users' ANL performance using Danish and non-semantic speech signals, the repeatability of ANL, and the association...

  13. Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Silke Neumann

    Full Text Available Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

  14. Two meals with different carbohydrate, fat and protein contents render equivalent postprandial plasma levels of calprotectin, cortisol, triglycerides and zonulin.

    Science.gov (United States)

    Ohlsson, Bodil; Darwiche, Gassan; Roth, Bodil; Höglund, Peter

    2016-11-01

    The aim was to compare postprandial plasma levels of calprotectin, cortisol, triglycerides and zonulin between a control breakfast and a moderately low-carbohydrate test breakfast, given randomly after 10-h fast. Blood samples were collected before and repeatedly after the meal. Plasma calprotectin, cortisol, triglycerides and zonulin were analyzed. The total area under the curve (tAUC) and change in AUC from baseline (dAUC) were calculated. Ratios between the test and control values were calculated to investigate equivalence. Healthy volunteers (8 men and 12 women; 46.0 ± 14.5 years) were included. tAUCs of cortisol and triglycerides did not differ between the breakfasts (p = 0.158 versus p = 0.579). Cortisol dAUCs were decreased and triglyceride dAUCs were increased after both breakfasts, with no differences between the breakfasts (p = 0.933 versus p = 0.277). Calprotectin and zonulin levels were unaffected. The meals were bioequivalent for cortisol, triglycerides and zonulin, but not for calprotectin.

  15. Aircrafts' taxi noise. Sound power level and directivity frequency band results

    NARCIS (Netherlands)

    Asensio, C.; Pavón, I.; Ruiz, M.; Pagan Munoz, Raul; Recuero, M.

    2009-01-01

    When noise mapping airports, the main noise sources are take offs and landings. But aircrafts' taxi noise can also be important, and should be considered, for instance when there are residential buildings near the airport's terminal. Main prediction tools, like Integrated Noise Model (INM), do not

  16. Longitudinal changes in hearing threshold levels of noise-exposed construction workers

    NARCIS (Netherlands)

    Leensen, Monique C. J.; Dreschler, Wouter A.

    2015-01-01

    Longitudinal analysis of audiometric data of a large population of noise-exposed workers provides insight into the development of noise-induced hearing loss (NIHL) as a function of noise exposure and age, particularly during the first decade of noise exposure. Data of pure-tone audiometry of 17,930

  17. SMORN-1: thermoelectrically generated noise in sheathed thermocouples and in other low level instrumentation cables

    International Nuclear Information System (INIS)

    Mathieu, F.; Meier, R.; Soenen, M.; Delcon, M.; Nysten, C.

    Starting from the fact that thermoelectric emfs of thermocouples are generated in the thermal gradients and not at the hot junction, it is shown how thermoelectric heterogeneity in conjunction with natural and forced convection phenomena gives rise to unwanted noise called: ''thermoelectric noise'' in the technological sense. A distinction is made between four different types of noise--i.e. uncorrelated noise, correlated noise, spectral noise and thermoelectric noise in the physical sense--each of which has its own characteristics. The experimental results presented reveal that noise amplitudes may be quite embarrassing when dealing with problems of quantitative signal fluctuation analysis. It is however emphasized that thermoelectric noise may also convey useful information which, without noise, might be lost

  18. Vibration and noise characteristics of hook type olive harvesters

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... The homeland of olive upper Mesopotamia including south-eastern ... Turkey where 81% of olive trees are grown in slopped and terraced .... effectively, it has been established the minimal security level at the equivalent noise ...

  19. Changing noise levels in a high CO2/lower pH ocean

    Science.gov (United States)

    Brewer, P. G.; Hester, K. C.; Peltzer, E. T.; Kirkwood, W. J.

    2008-12-01

    We show that ocean acidification from fossil fuel CO2 invasion and from increased respiration/reduced ventilation, has significantly reduced ocean sound absorption and thus increased ocean noise levels in the kHz frequency range. Below 10 kHz, sound absorption occurs due to well known chemical relaxations in the B(OH)3/B(OH)4- and HCO3-/CO32- systems. The pH dependence of these chemical relaxations results in decreased sound absorption (α = dB/km) as the ocean becomes more acidic from increased CO2 levels. The scale of surface ocean pH change today from the +105 ppmv change in atmospheric CO2 is about - 0.12 pH, resulting in frequency dependent decreases in sound absorption that now exceed 12% over pre- industrial. Under reasonable projections of future fossil fuel CO2 emissions and other sources a pH change of 0.3 units or more can be anticipated by mid-century, resulting in a decrease in α by almost 40%. Increases in water temperature have a smaller effect but also contribute to decreased sound absorption. Combining a lowering of 0.3 pH units with an increase of 3°C, α will decrease further to almost 45%. Ambient noise levels in the ocean within the auditory range critical for environmental, military, and economic interests are set to increase significantly due to the combined effects of decreased absorption and increasing sources from mankind's activities. Incorporation of sound absorption in modeling future ocean scenarios (R. Zeebe, personal communication) and long-term monitoring possibly with the aid of modern cabled observatories can give insights in how ocean noise will continue to change and its effect on groups such as marine mammals which communicate in the affected frequency range.

  20. Assessment of traffic noise levels in urban areas using different soft computing techniques.

    Science.gov (United States)

    Tomić, J; Bogojević, N; Pljakić, M; Šumarac-Pavlović, D

    2016-10-01

    Available traffic noise prediction models are usually based on regression analysis of experimental data, and this paper presents the application of soft computing techniques in traffic noise prediction. Two mathematical models are proposed and their predictions are compared to data collected by traffic noise monitoring in urban areas, as well as to predictions of commonly used traffic noise models. The results show that application of evolutionary algorithms and neural networks may improve process of development, as well as accuracy of traffic noise prediction.

  1. Determination of no-observed effect level (NOEL-biomarker equivalents to interpret biomonitoring data for organophosphorus pesticides in children

    Directory of Open Access Journals (Sweden)

    Bouchard Michèle

    2009-02-01

    Full Text Available Abstract Background Environmental exposure to organophosphorus pesticides has been characterized in various populations, but interpretation of these data from a health risk perspective remains an issue. The current paper proposes biological reference values to help interpret biomonitoring data related to an exposure to organophosphorus pesticides in children for which measurements of alkylphosphate metabolites are available. Methods Published models describing the kinetics of malathion and chlorpyrifos in humans were used to determine no-observed effect level – biomarker equivalents for methylphosphates and ethylphosphates, respectively. These were expressed in the form of cumulative urinary amounts of alkylphosphates over specified time periods corresponding to an absorbed no-observed effect level dose (derived from a published human exposure dose and assuming various plausible exposure scenarios. Cumulative amounts of methylphosphate and ethylphosphate metabolites measured in the urine of a group of Quebec children were then compared to the proposed biological reference values. Results From a published no-observed effect level dose for malathion and chlorpyrifos, the model predicts corresponding oral biological reference values for methylphosphate and ethylphosphate derivatives of 106 and 52 nmol/kg of body weight, respectively, in 12-h nighttime urine collections, and dermal biological reference values of 40 and 32 nmol/kg of body weight. Out of the 442 available urine samples, only one presented a methylphosphate excretion exceeding the biological reference value established on the basis of a dermal exposure scenario and none of the methylphosphate and ethylphosphate excretion values were above the obtained oral biological reference values, which reflect the main exposure route in children. Conclusion This study is a first step towards the development of biological guidelines for organophophorus pesticides using a toxicokinetic modeling

  2. Comparison of clinical parameters and environmental noise levels between regular surgery and piezosurgery for extraction of impacted third molars

    Directory of Open Access Journals (Sweden)

    Hao-Hueng Chang

    2015-10-01

    Conclusion: The piezosurgery device produced noise levels similar to or lower than those of the high-speed drilling device. However, piezosurgery provides advantages of increased patient comfort during extraction of impacted third molars.

  3. Estimation of low-level neutron dose-equivalent rate by using extrapolation method for a curie level Am–Be neutron source

    International Nuclear Information System (INIS)

    Li, Gang; Xu, Jiayun; Zhang, Jie

    2015-01-01

    Neutron radiation protection is an important research area because of the strong radiation biological effect of neutron field. The radiation dose of neutron is closely related to the neutron energy, and the connected relationship is a complex function of energy. For the low-level neutron radiation field (e.g. the Am–Be source), the commonly used commercial neutron dosimeter cannot always reflect the low-level dose rate, which is restricted by its own sensitivity limit and measuring range. In this paper, the intensity distribution of neutron field caused by a curie level Am–Be neutron source was investigated by measuring the count rates obtained through a 3 He proportional counter at different locations around the source. The results indicate that the count rates outside of the source room are negligible compared with the count rates measured in the source room. In the source room, 3 He proportional counter and neutron dosimeter were used to measure the count rates and dose rates respectively at different distances to the source. The results indicate that both the count rates and dose rates decrease exponentially with the increasing distance, and the dose rates measured by a commercial dosimeter are in good agreement with the results calculated by the Geant4 simulation within the inherent errors recommended by ICRP and IEC. Further studies presented in this paper indicate that the low-level neutron dose equivalent rates in the source room increase exponentially with the increasing low-energy neutron count rates when the source is lifted from the shield with different radiation intensities. Based on this relationship as well as the count rates measured at larger distance to the source, the dose rates can be calculated approximately by the extrapolation method. This principle can be used to estimate the low level neutron dose values in the source room which cannot be measured directly by a commercial dosimeter. - Highlights: • The scope of the affected area for

  4. Theory of deep level trap effects on generation-recombination noise in HgCdTe photoconductors

    International Nuclear Information System (INIS)

    Iverson, A.E.; Smith, D.L.

    1985-01-01

    We present a theory of the effect of deep level centers on the generation-recombination (g-r) noise and responsivity of an intrinsic photoconductor. The deep level centers can influence the g-r noise and responsivity in three main ways: (i) they can shorten the bulk carrier lifetime by Shockley--Read--Hall recombination; (ii) for some values of the capture cross sections, deep level densities, and temperature, the deep levels can trap a significant fraction of the photogenerated minority carriers. This trapping reduces the effective minority carrier mobility and diffusivity and thus reduces the effect of carrier sweep out on both g-r noise and responsivity; (iii) the deep level centers add a new thermal noise source, which results from fluctuations between bound and free carriers. The strength of this new noise source decreases with decreasing temperature at a slower rate than band-to-band thermal g-r noise. Calculations have been performed for a X = 0.21, n-type Hg/sub 1-x/Cd/sub x/Te photoconductor using the parameters of a commonly occurring deep level center in this material. We find that for typical operating conditions photoconductive detector performance begins to degrade as the deep level density begins to exceed 10 16 cm -3

  5. Seasonal Changes in Atmospheric Noise Levels and the Annual Variation in Pigeon Homing Performance

    Science.gov (United States)

    Hagstrum, J. T.; McIsaac, H. P.; Drob, D. P.

    2015-12-01

    The remarkable navigational ability of homing pigeons (Columba livia) is influenced by a number of factors, an unknown one of which causes the "Wintereffekt"1 or annual variation in homing performance. Minima in homeward orientation and return speeds have been observed in winter, with maxima in summer, during repetitive pigeon releases from single sites near experimental lofts in Wilhelmshaven, Göttingen, and Munich, Germany, and near Pisa, Italy1-4. Overall the annual variation is more pronounced in northern Germany than Italy4, and both mature and juvenile cohorts respond to this seasonal factor. Older, more experienced pigeons are better at compensating for its effects than naïve ones, but are still affected after numerous releases. The narrow low-frequency band of atmospheric background noise (microbaroms; 0.1-0.3 Hz) also varies with an annual cycle that generally has higher amplitudes in winter than in summer depending on location5. In addition, homing pigeons, and possibly other birds, apparently use infrasonic signals of similar frequency as navigational cues6, and a seasonal variation in background noise levels could cause corresponding changes in signal-to-noise ratios and thus in homing performance. The annual variation in homing performance, however, was not observed during long-term pigeon releases at two sites in eastern North America. The annual and geographic variability in homing performance in the northern hemisphere can be explained to a first order by seasonal changes in infrasonic noise sources related to ocean storm activity, and to the direction and intensity of stratospheric winds. In addition, increased dispersion in departure bearings of individual birds for some North American releases were likely caused by additional infrasonic noise associated with severe weather events during tornado and Atlantic hurricane seasons. 1Kramer, G. & von Saint Paul, U., J. Ornithol. 97, 353-370 (1956); 2Wallraff, H. G., Z. Tierpsychol. 17, 82-113 (1960

  6. Non-Equivalence at Idiomatic and Expressional Level and the Strategies to Deal with: English Translation into Persian

    Directory of Open Access Journals (Sweden)

    Ahmad Ezzati Vazifehkhah

    2017-10-01

    Full Text Available The main purpose of this paper is to throw some light on non-equivalence at an idiomatic and expressional level in a contrastive analysis framework from English translation into Persian. The present paper makes an effort to analyze six main strategies such as using an idiom or an expression of similar meaning and form, similar meaning but dissimilar form, borrowing the source language, translation by paraphrase, translation by omission of a play on idiom or expression and translation by omission of entire idiom or expression (Baker, 2011. Hence, the core properties of this issue are described both in English and Persian languages. Moreover, within the text, there is a comparison which is conducted to highlight the matches and mismatches between these two languages. Further, other translators may well take this information as one of the main platforms from which they find out some strategies in translation idioms and expressions. This study concludes Baker’s (2011 proposed strategies are applicable and then proposes some weighty recommendations to be taken by translators in such a demanding issue.

  7. Noise study in laboratories with exhaust fans

    International Nuclear Information System (INIS)

    Shaikh, G.H.; Hashmi, R.; Shareef, A.

    2005-01-01

    Noise study has been carried out in 25 laboratories fitted with exhaust fans. We have studied A- Weighted equivalent sound pressure levels (dB(A) LAeJ and equivalent octave band sound pressure levels (dB L/sub eq/ in each of the laboratories surveyed. The data collected has been analyzed for Preferred Speech Interference Levels (PSIL). The results show that the interior noise levels in these laboratories vary from 59.6 to 72.2 dB(A) L/sub Aeq/, which are very high and much beyond the interior noise limits recommended for laboratories. Some ways and means to limit emission of high-level noise from exhaust fans are also discussed. (author)

  8. WIPP WAC Equivalence Support Measurements for Low-Level Sludge Waste at Los Alamos National Laboratory - 12242

    Energy Technology Data Exchange (ETDEWEB)

    Gruetzmacher, Kathleen M.; Bustos, Roland M.; Ferran, Scott G.; Gallegos, Lucas E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lucero, Randy P. [Pajarito Scientific Corporation, Santa Fe, New Mexico 87507 (United States)

    2012-07-01

    Los Alamos National Laboratory (LANL) uses the Nevada National Security Site (NNSS) as an off-site disposal facility for low-level waste (LLW), including sludge waste. NNSS has issued a position paper that indicates that systems that are not certified by the Carlsbad Field Office (CBFO) for Waste Isolation Pilot Plant (WIPP) disposal of Transuranic (TRU) waste must demonstrate equivalent practices to the CBFO certified systems in order to assign activity concentration values to assayed items without adding in the Total Measurement Uncertainty (TMU) when certifying waste for NNSS disposal. Efforts have been made to meet NNSS requirements to accept sludge waste for disposal at their facility. The LANL LLW Characterization Team uses portable high purity germanium (HPGe) detector systems for the nondestructive assay (NDA) of both debris and sludge LLW. A number of performance studies have been conducted historically by LANL to support the efficacy and quality of assay results generated by the LANL HPGe systems, and, while these detector systems are supported by these performance studies and used with LANL approved procedures and processes, they are not certified by CBFO for TRU waste disposal. Beginning in 2009, the LANL LLW Characterization Team undertook additional NDA measurements of both debris and sludge simulated waste containers to supplement existing studies and procedures to demonstrate full compliance with the NNSS position paper. Where possible, Performance Demonstration Project (PDP) drums were used for the waste matrix and PDP sources were used for the radioactive sources. Sludge drums are an example of a matrix with a uniform distribution of contaminants. When attempting to perform a gamma assay of a sludge drum, it is very important to adequately simulate this uniform distribution of radionuclides in order to accurately model the assay results. This was accomplished by using a spiral radial source tube placement in a sludge drum rather than the standard

  9. Equivalent Lagrangians

    International Nuclear Information System (INIS)

    Hojman, S.

    1982-01-01

    We present a review of the inverse problem of the Calculus of Variations, emphasizing the ambiguities which appear due to the existence of equivalent Lagrangians for a given classical system. In particular, we analyze the properties of equivalent Lagrangians in the multidimensional case, we study the conditions for the existence of a variational principle for (second as well as first order) equations of motion and their solutions, we consider the inverse problem of the Calculus of Variations for singular systems, we state the ambiguities which emerge in the relationship between symmetries and conserved quantities in the case of equivalent Lagrangians, we discuss the problems which appear in trying to quantize classical systems which have different equivalent Lagrangians, we describe the situation which arises in the study of equivalent Lagrangians in field theory and finally, we present some unsolved problems and discussion topics related to the content of this article. (author)

  10. Psychophysical assessment of sinusoidal whole-body vibration in z-axis between 0.6 and 5 Hz combined with different noise levels.

    Science.gov (United States)

    Seidel, H; Richter, J; Kurerov, N N; Schajpak, E J; Blüthner, R; Erdmann, U; Hinz, B

    1989-01-01

    Nine healthy sitting males evaluated the intensity of vertical whole-body vibration (WBV) in z-axis at four frequencies (F1 = 0.63 Hz, F2 = 1.25 Hz, F3 = 2.5 Hz, F4 = 5 Hz) and two intensities (I1 = 1 ms-2 rms, I2 = 2 ms-2 rms) by cross-modality matching (CMM). The subjects were simultaneously exposed to low-frequency noise at two levels (L1 = 65 dBA, L2 = 86 dBA). L1 and L2 were context conditions which did not have to be evaluated by CMM. The results indicate a flat response between F2 and F3; the sensitivity increases towards F1. Different exponents of Stevens' power law for the frequencies of WBV contradict the frequency range tested to be a sensory continuum. L2 caused practically significantly stronger sensations of the WBV-intensity from F1 to F3 (I1) and at F2 (I2). No synergistic effect of noise and WBV was shown at F3I2. Weighting factors were calculated for all exposure conditions using Stevens' power law. The weighting of F2 and F3 contradicts that of the International Standard ISO 2631-1985 (E). The results enable recommendations for the frequency weighting of WBV between 0.63 and 1 Hz, as well as for the equivalence of noise and WBV with combined exposure.

  11. Investigation of the performance of digital mammographic X-Ray equipment: Determination of noise equivalent quanta (NEQQC) and detective quantum efficiency (DQEQC) compared with the automated analysis of CDMAM test images with CDCOM and CDIC programs

    International Nuclear Information System (INIS)

    Loos, C.; Buhr, H.; Blendl, C.

    2013-01-01

    Purpose: The purpose of this study was to determine the values for noise equivalent quanta, detective quantum efficiency, modulation transfer function, noise power spectrum, and the values for the parameters for automated CDMAM test phantom analyses required to achieve satisfactory quality of digital mammograms. Materials and Methods: During the course of tests according to PAS 1054 (8 CR and 12 DR systems), test images were made with a test phantom insertion plate containing two lead edges in nearly horizontal and vertical directions. Only original data were processed with a program that was developed at the Cologne University of Applied Sciences (FH-Koeln). All equipment systems complied with the requirements regarding visual recognition of gold-plated mammo detail test objects. CDMAM test images were also evaluated using the CDIC (CUAS) and CDCOM (EUREF) programs. Results: CDMAM test images show comparable values for the parameters, precision, sensitivity and specificity. DR systems require about half the dose used for CR systems for similar results. The NEQ values achieved with the dose used for the CDMAM test images show larger scatter ranges. The MTF of the different equipment system types differ significantly from each other. Conclusion: Visual evaluation of CDMAM test images can be replaced by automated evaluation. Limiting values were determined for each parameter. Automated evaluation of CDMAM test phantom images should be used to determine the physical parameter NEQ QC . This method is much more sensitive to noise and sharpness influences and has a higher validity than diagnostic methods. Automated evaluation objectivizes testing. (orig.)

  12. The consequences of a reduction in the administratively applied maximum annual dose equivalent level for an individual in a group of occupationally exposed workers

    International Nuclear Information System (INIS)

    Harrison, N.T.

    1980-02-01

    An analysis is described for predicting the consequences of a reduction in the administratively applied maximum dose equivalent level to individuals in a group of workers occupationally exposed to ionising radiations, for the situation in which no changes are made to the working environment. This limitation of the maximum individual dose equivalent is accommodated by allowing the number of individuals in the working group to increase. The derivation of the analysis is given, together with worked examples, which highlight the important assumptions that have been made and the conclusions that can be drawn. The results are obtained in the form of the capacity of the particular working environment to accommodate the limitation of the maximum individual dose equivalent, the increase in the number of workers required to carry out the productive work and any consequent increase in the occupational collective dose equivalent. (author)

  13. An examination of methods whereby noise levels in current and new mining equipment may be reduced

    CSIR Research Space (South Africa)

    Maneylaws, A

    1997-12-01

    Full Text Available An extensive literature review of international work of mining equipment noise control has been carried out. The sources of noise on percussion rock drills, continuous miners, dust scrubbers and fans, long wall machinery and trackless vehicles...

  14. Noise levels in a neonatal intensive care unit in the Cape metropole ...

    African Journals Online (AJOL)

    Introduction. Continuous noise exposure is potentially harmful to infants\\' auditory systems and wellbeing. Although the effects of noise on infants in a neonatal intensive care unit (NICU) have been well researched overseas, limited studies have been conducted in South Africa. Aim. To conduct a detailed noise assessment ...

  15. Noise Considerations in Resistance Bridges

    DEFF Research Database (Denmark)

    Diamond, Joseph M.

    1963-01-01

    A signal-to-noise analysis is made of the Wheatstone bridge, where the unknown and standard resistors may be at different temperatures, a situation which occurs in resistance thermometry. The limiting condition is assumed to be dissipation in the unknown resistor. It is shown that the ratio arms...... thermometry, where the noise in the unknown resistor will predominate strongly. An impedance step-up device (transformer or tuned circuit) is valuable in raising the bridge signal and noise level above the noise of the first amplifier tube. However, as the step-up ratio is increased, two counterfactors appear....... With certain assumptions about the noise and grid current of the first tube it is found that the equivalent temperature of a unity ratio (Mueller) bridge used for liquid helium measurements may be 400°K....

  16. Measurement of nuclear reactor noise at low power levels; Merenje nuklearnog reaktorskog suma na malim snagama

    Energy Technology Data Exchange (ETDEWEB)

    Velickovic, Lj; Petrovic, M [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1968-11-15

    Spatial and time dependence relation of neutrons from fission and other reactions in the reactor core result in non Poisson fluctuations of neutron density. Analytical formula developed for auto-correlation function includes physical parameters which characterize time behaviour of neutrons in the reactor system. Since auto-correlation function can be easily measured, it is a useful tool for experimental determination of these parameters. Noise from the ionization chamber was measured and analyzed by a digital computer. measurements were analyzed completely in the time domain (auto-correlation functions). This enabled separating the noise caused by neutron detection from the noise from neutron density fluctuation in the reactor. All the results can be analyzed by spatial independent reactor theory. Physical analysis of reactor noise was limited to determination of {beta}/l ratio from auto-correlation measurements at 0.5 W power level (RB reactor in Vinca). Three different reactor core lattices were analyzed (lattice pitch 8 cm, 11.3 cm and 14 cm). It was shown that parameter {beta}/l could be determined from auto-correlation measurements of neutron density with high precision (few percents) Prostorna i vremenska povezanost neutrona koji nastaju u fisiji i drugim procesima koji se desavaju u reaktoru dovodi do ne Poisson-ovih fluktuacija neutronske gustine. Analiticka formula, razvijena za autokorelacionu funkciju ovih fluktuacija, sadrzi fizicke parametre koji karakterisu vremensko ponasanje neutrona u reaktorskom sistemu. Kako autokorelaciona funkcija moze lako da se meri, ona je korisno sredstvo za eksperimentalno odredjivanje ovih parametara. Sum iz jonizacione komore digitalno je meren i analiziran u digitalnom racunaru. Merenja su kompletno analizirana u vremenskom domenu (autokorelacione funkeije). To je olaksalo razdvajanje suma izazvanog procesom neutronske detekcije od suma koji potice od fluktuacija neutronske gustine u reaktorskom sistemu. Svi rezultati

  17. Power distribution and substrate noise coupling investigations on the behavioral level for photon counting imaging readout circuits

    International Nuclear Information System (INIS)

    Lundgren, Jan; Abdalla, Suliman; O'Nils, Mattias; Oelmann, Bengt

    2007-01-01

    In modern mixed-signal system design, there are increasing problems associated with noise coupling caused by switching digital parts to sensitive analog parts. As a consequence, there is a growing necessity to understand these problems. In order to avoid costly design iterations, noise coupling simulations should be initiated as early as possible in the design chain. The problems associated with on-chip noise coupling have been discovered in photon counting pixel detector readout systems, where the level of integration of analog and digital circuits is very high on a very small area, and it would appear that these problems will continue to increase for future system designs in this field. This paper deals with the functionality of utilizing behavioral level models for simulating noise coupling in these readout systems. The methods and models are described and simulation results are shown for a photon counting pixel detector readout system

  18. Sea Ice Deformation State From Synthetic Aperture Radar Imagery - Part II: Effects of Spatial Resolution and Noise Level

    DEFF Research Database (Denmark)

    Dierking, Wolfgang; Dall, Jørgen

    2008-01-01

    C- and L-band airborne synthetic aperture radar (SAR) imagery acquired at like- and cross-polarization over sea ice under winter conditions is examined with the objective to study the discrimination between level ice and ice deformation features. High-resolution low-noise data were analysed...... in the first paper. In this second paper, the main topics are the effects of spatial resolution and signal-to-noise ratio. Airborne, high-resolution SAR scenes are used to generate a sequence of images with increasingly coarser spatial resolution from 5 m to 25 m, keeping the number of looks constant....... The signal-to-noise ratio is varied between typical noise levels for airborne imagery and satellite data. Areal fraction of deformed ice and average deformation distance are determined for each image product. At L-band, the retrieved values of the areal fraction get larger as the image resolution is degraded...

  19. Neural indices of phonemic discrimination and sentence-level speech intelligibility in quiet and noise: A P3 study.

    Science.gov (United States)

    Koerner, Tess K; Zhang, Yang; Nelson, Peggy B; Wang, Boxiang; Zou, Hui

    2017-07-01

    This study examined how speech babble noise differentially affected the auditory P3 responses and the associated neural oscillatory activities for consonant and vowel discrimination in relation to segmental- and sentence-level speech perception in noise. The data were collected from 16 normal-hearing participants in a double-oddball paradigm that contained a consonant (/ba/ to /da/) and vowel (/ba/ to /bu/) change in quiet and noise (speech-babble background at a -3 dB signal-to-noise ratio) conditions. Time-frequency analysis was applied to obtain inter-trial phase coherence (ITPC) and event-related spectral perturbation (ERSP) measures in delta, theta, and alpha frequency bands for the P3 response. Behavioral measures included percent correct phoneme detection and reaction time as well as percent correct IEEE sentence recognition in quiet and in noise. Linear mixed-effects models were applied to determine possible brain-behavior correlates. A significant noise-induced reduction in P3 amplitude was found, accompanied by significantly longer P3 latency and decreases in ITPC across all frequency bands of interest. There was a differential effect of noise on consonant discrimination and vowel discrimination in both ERP and behavioral measures, such that noise impacted the detection of the consonant change more than the vowel change. The P3 amplitude and some of the ITPC and ERSP measures were significant predictors of speech perception at segmental- and sentence-levels across listening conditions and stimuli. These data demonstrate that the P3 response with its associated cortical oscillations represents a potential neurophysiological marker for speech perception in noise. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Quality-aware features-based noise level estimator for block matching and three-dimensional filtering algorithm

    Science.gov (United States)

    Xu, Shaoping; Hu, Lingyan; Yang, Xiaohui

    2016-01-01

    The performance of conventional denoising algorithms is usually controlled by one or several parameters whose optimal settings depend on the contents of the processed images and the characteristics of the noises. Among these parameters, noise level is a fundamental parameter that is always assumed to be known by most of the existing denoising algorithms (so-called nonblind denoising algorithms), which largely limits the applicability of these nonblind denoising algorithms in many applications. Moreover, these nonblind algorithms do not always achieve the best denoised images in visual quality even when fed with the actual noise level parameter. To address these shortcomings, in this paper we propose a new quality-aware features-based noise level estimator (NLE), which consists of quality-aware features extraction and optimal noise level parameter prediction. First, considering that image local contrast features convey important structural information that is closely related to image perceptual quality, we utilize the marginal statistics of two local contrast operators, i.e., the gradient magnitude and the Laplacian of Gaussian (LOG), to extract quality-aware features. The proposed quality-aware features have very low computational complexity, making them well suited for time-constrained applications. Then we propose a learning-based framework where the noise level parameter is estimated based on the quality-aware features. Based on the proposed NLE, we develop a blind block matching and three-dimensional filtering (BBM3D) denoising algorithm which is capable of effectively removing additive white Gaussian noise, even coupled with impulse noise. The noise level parameter of the BBM3D algorithm is automatically tuned according to the quality-aware features, guaranteeing the best performance. As such, the classical block matching and three-dimensional algorithm can be transformed into a blind one in an unsupervised manner. Experimental results demonstrate that the

  1. Seasonal variation of seismic ambient noise level at King Sejong Station, Antarctica

    Science.gov (United States)

    Lee, W.; Sheen, D.; Seo, K.; Yun, S.

    2009-12-01

    The generation of the secondary- or double-frequency (DF) microseisms with dominant frequencies between 0.1 and 0.5 Hz has been explained by nonlinear second-order pressure perturbations on the ocean bottom due to the interference of two ocean waves of equal wavelengths traveling in opposite directions. Korea Polar Research Institute (KOPRI) has been operating a broadband seismic station (KSJ1) at King George Island (KGI), Antarctica, since 2001. Examining the ambient seismic noise level for the period from 2006 to 2008 at KSJ1, we found a significant seasonal variation in the frequency range 0.1-0.5 Hz. Correlation of the DF peaks with significant ocean wave height and peak wave period models indicates that the oceanic infragravity waves in the Drake Passage is a possible source to excite the DF microseisms at KGI. Location of King Sejong Station, Antarctica Seasonal variations of DF peak, significant wave height, and peak wave period

  2. Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.

    Directory of Open Access Journals (Sweden)

    Irene K Voellmy

    Full Text Available Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic factors can influence predator-prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour, compared with control conditions (playback of recordings from the same harbours without ship noise, affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus and the European minnow (Phoxinus phoxinus, which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.

  3. The effect of extending high-frequency bandwidth on the acceptable noise level (ANL) of hearing-impaired listeners.

    Science.gov (United States)

    Johnson, Earl; Ricketts, Todd; Hornsby, Benjamin

    2009-01-01

    This study examined the effects of extending high-frequency bandwidth, for both a speech signal and a background noise, on the acceptable signal-to-noise ratio (SNR) of listeners with mild sensorineural hearing loss through utilization of the Acceptable Noise Level (ANL) procedure. In addition to extending high-frequency bandwidth, the effects of reverberation time and background noise type and shape were also examined. The study results showed a significant increase in the mean ANL (i.e. participants requested a better SNR for an acceptable listening situation) when high-frequency bandwidth was extended from 3 to 9 kHz and from 6 to 9 kHz. No change in the ANL of study participants was observed as a result of isolated modification to reverberation time or background noise stimulus. An interaction effect, however, of reverberation time and background noise stimulus was demonstrated. These findings may have implications for future design of hearing aid memory programs for listening to speech in the presence of broadband background noise.

  4. Current Background Noise Sources and Levels in the NASA Ames 40- by 80-Foot Wind Tunnel: A Status Report

    Science.gov (United States)

    Allen, Christopher S.; Jaeger, Stephen; Soderman, Paul; Koga, Dennis (Technical Monitor)

    1999-01-01

    Background noise measurements were made of the acoustic environment in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel (40x80) at NASA Ames Research Center. The measurements were acquired subsequent to the 40x80 Aeroacoustic Modernization Project, which was undertaken to improve the anechoic characteristics of the 40x80's closed test section as well as reduce the levels of background noise in the facility. The resulting 40x80 anechoic environment was described by Soderman et. al., and the current paper describes the resulting 40x80 background noise, discusses the sources of the noise, and draws comparisons to previous 40x80 background noise levels measurements. At low wind speeds or low frequencies, the 40x80 background noise is dominated by the fan drive system. To obtain the lowest fan drive noise for a given tunnel condition, it is possible in the 40x80 to reduce the fans' rotational speed and adjust the fans' blade pitch, as described by Schmidtz et. al. This idea is not new, but has now been operationally implemented with modifications for increased power at low rotational speeds. At low to mid-frequencies and at higher wind speeds, the dominant noise mechanism was thought to be caused by the surface interface of the previous test section floor acoustic lining. In order to reduce this noise mechanism, the new test section floor lining was designed to resist the pumping of flow in and out of the space between the grating slats required to support heavy equipment. In addition, the lining/flow interface over the entire test section was designed to be smoother and quieter than the previous design. At high wind speeds or high frequencies, the dominant source of background noise in the 40x80 is believed to be caused by the response of the in-flow microphone probes (required by the nature of the closed test section) to the fluctuations in the freestream flow. The resulting background noise levels are also different for probes of various

  5. Ambient seismic noise levels: A survey of the permanent and temporary seismographic networks in Morocco, North Africa

    Science.gov (United States)

    El Fellah, Y.; Khairy Abd Ed-Aal, A.; El Moudnib, L.; Mimoun, H.; Villasenor, A.; Gallart, J.; Thomas, C.; Elouai, D.; Mimoun, C.; Himmi, M.

    2013-12-01

    Abstract The results, of a conducted study carried out to analyze variations in ambient seismic noise levels at sites of the installed broadband stations in Morocco, North Africa, are obtained. The permanent and the temporary seismic stations installed in Morocco of the Scientific Institute ( IS, Rabat, Morocco), institute de Ciencias de la Tierra Jaume almera (ICTJA, Barcelona, Spain) and Institut für Geophysik (Munster, Germany) were used in this study. In this work, we used 23 broadband seismic stations installed in different structural domains covering all Morocco from south to north. The main purposes of the current study are: 1) to present a catalog of seismic background noise spectra for Morocco obtained from recently installed broadband stations, 2) to assess the effects of experimental temporary seismic vault construction, 3) to determine the time needed for noise at sites to stabilize, 4) to establish characteristics and origin of seismic noise at those sites. We calculated power spectral densities of background noise for each component of each broadband seismometer deployed in the different investigated sites and then compared them with the high-noise model and low-noise Model of Peterson (1993). All segments from day and night local time windows were included in the calculation without parsing out earthquakes. The obtained results of the current study could be used forthcoming to evaluate permanent station quality. Moreover, this study could be considered as a first step to develop new seismic noise models in North Africa not included in Peterson (1993). Keywords Background noise; Power spectral density; Model of Peterson; Scientific Institute; Institute de Ciencias de la Tierra Jaume almera; Institut für Geophysik

  6. Equivalent threshold sound pressure levels for Sennheiser HDA 200 earphone and Etymotic Research ER-2 insert earphone in the frequency range 125 Hz to 16 kHz

    DEFF Research Database (Denmark)

    Han, Loc A; Poulsen, Torben

    1998-01-01

    Equivalent Threshold Sound Pressure Levels (ETSPLs) have been determined for the Sennheiser HDA 200 earphone and the Etymotic Research ER-2insert earphone. Thirty-one young normal-hearing test subjects participated and the thresholds were determined for all recommended frequencies in thefrequency...

  7. Re-establishment of the air kerma and ambient dose equivalent standards for the BIPM protection-level 60Co beam

    International Nuclear Information System (INIS)

    Kessler, C.; Roger, P.

    2005-07-01

    The air kerma and ambient dose equivalent standards for the protection-level 60 Co beam have been re-established following the repositioning of the irradiator and modifications to the beam. Details concerning the standards and the new uncertainty budgets are described in this report with their implications for dosimetry comparisons and calibrations. (authors)

  8. Hearing Threshold and Equal Loudness Level Contours of 1/3-octave Noise Bands in a Diffuse Sound Field

    DEFF Research Database (Denmark)

    Nielsen, Maja Kirstine E.; Poulsen, Torben

    1994-01-01

    Hearing threshold levels and equal loudness level contours of 1/3-octave noise bands at 40 phons and 60 phon were measured for 27 normal hearing listeners in an approximately diffuse sound field. The threshold data in the frequency range 125 Hz to 1 kHz were 3-6 dB higher than the values given...

  9. Cross-cultural measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) in patients with type 2 diabetes mellitus in Singapore.

    Science.gov (United States)

    Wang, Ye; Tan, Ngiap-Chuan; Tay, Ee-Guan; Thumboo, Julian; Luo, Nan

    2015-07-16

    This study aimed to assess the measurement equivalence of the 5-level EQ-5D (EQ-5D-5L) among the English, Chinese, and Malay versions. A convenience sample of patients with type 2 diabetes mellitus were enrolled from a public primary health care institution in Singapore. The survey questionnaire comprised the EQ-5D-5L and questions assessing participants' socio-demographic and clinical characteristics. Multiple linear regression models were used to assess the difference in EQ-5D-5L index (calculated using an interim algorithm) and EQ-visual analog scale (EQ-VAS) scores across survey language (Chinese vs. English, Malay vs. English, and Malay vs. Chinese). Measurement equivalence was examined by comparing the 90% confidence interval of difference in the EQ-5D-5L index and EQ-VAS scores with a pre-determined equivalence margin. Multiple logistic regression models were used to assess the response patterns of the 5 Likert-type items of the EQ-5D-5L across survey language. Equivalence was demonstrated between the Chinese and English versions and between the Malay and English versions of the EQ-5D-5L index scores. Equivalence was also demonstrated between the Chinese and English versions and between the Malay and Chinese versions of the EQ-VAS scores. Equivalence could not be determined between the Malay and Chinese versions of the EQ-5D-5L index score and between the Malay and English versions of the EQ-VAS score. No significant difference was found in responses to EQ-5D-5L items between any languages, except that patients who chose to complete the Chinese version were more likely to report "no problems" in mobility compared to those who completed the Malay version of the questionnaire. This study provided evidence for the measurement equivalence of the different language versions of EQ-5D-5L in Singapore.

  10. Tree-level equivalence between a Lorentz-violating extension of QED and its dual model in electron-electron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Toniolo, Giuliano R.; Fargnoli, H.G.; Brito, L.C.T. [Universidade Federal de Lavras, Departamento de Fisica, Caixa Postal 3037, Lavras, Minas Gerais (Brazil); Scarpelli, A.P.B. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Sao Paulo (Brazil)

    2017-02-15

    S-matrix amplitudes for the electron-electron scattering are calculated in order to verify the physical equivalence between two Lorentz-breaking dual models. We begin with an extended Quantum Electrodynamics which incorporates CPT-even Lorentz-violating kinetic and mass terms. Then, in a process of gauge embedding, its gauge-invariant dual model is obtained. The physical equivalence of the two models is established at tree level in the electron-electron scattering and the unpolarized cross section is calculated up to second order in the Lorentz-violating parameter. (orig.)

  11. Tree-level equivalence between a Lorentz-violating extension of QED and its dual model in electron-electron scattering

    International Nuclear Information System (INIS)

    Toniolo, Giuliano R.; Fargnoli, H.G.; Brito, L.C.T.; Scarpelli, A.P.B.

    2017-01-01

    S-matrix amplitudes for the electron-electron scattering are calculated in order to verify the physical equivalence between two Lorentz-breaking dual models. We begin with an extended Quantum Electrodynamics which incorporates CPT-even Lorentz-violating kinetic and mass terms. Then, in a process of gauge embedding, its gauge-invariant dual model is obtained. The physical equivalence of the two models is established at tree level in the electron-electron scattering and the unpolarized cross section is calculated up to second order in the Lorentz-violating parameter. (orig.)

  12. Noise exposure in movie theaters: a preliminary study of sound levels during the showing of 25 films.

    Science.gov (United States)

    Warszawa, Anna; Sataloff, Robert T

    2010-09-01

    The harmful effects of noise exposure during leisure-time activities are beginning to receive some scrutiny. We conducted a preliminary study to investigate the noise levels during the showings of 25 different films. During each screening, various sound measurements were made with a dosimeter. The movies were classified on the basis of both their Motion Picture Association of America (MPAA) rating and their genre, and the size of the theater and the size of the audience were taken into consideration in the final analysis. Our findings suggest that the sound levels of many movies might be harmful to hearing, although we can draw no definitive conclusions. We did not discern any relationship between noise levels and either MPAA rating or genre. Further studies are recommended.

  13. Feedback damping of a microcantilever at room temperature to the minimum vibration amplitude limited by the noise level.

    Science.gov (United States)

    Kawamura, Y; Kanegae, R

    2016-06-17

    Cooling the vibration amplitude of a microcantilever as low as possible is important to improve the sensitivity and resolutions of various types of scanning type microscopes and sensors making use of it. When the vibration amplitude is controlled to be smaller using a feed back control system, it is known that the obtainable minimum amplitude of the vibration is limited by the floor noise level of the detection system. In this study, we demonstrated that the amplitude of the thermal vibration of a microcantilever was suppressed to be about 0.15 pmHz(-1/2), which is the same value with the floor noise level, without the assistance of external cryogenic cooling. We think that one of the reason why we could reach the smaller amplitude at room temperature is due to stiffer spring constant of the lever, which leads to higher natural frequency and consequently lower floor noise level. The other reason is considered to be due to the increase in the laser power for the diagnostics, which lead to the decrease in the signal to noise ratio determined by the optical shot noise.

  14. Ionizing Radiation Effects on the Noise of 65 nm CMOS Transistors for Pixel Sensor Readout at Extreme Total Dose Levels

    CERN Document Server

    Re, V.; Manghisoni, M.; Riceputi, E.; Traversi, G.; Ratti, L.

    2018-01-01

    This paper is focused on the study of the noise performance of 65 nm CMOS transistors at extremely high total ionizing dose (TID) levels of the order of several hundreds of Mrad(SiO2). Noise measurements are reported and discussed, analyzing radiation effects on 1/ f noise and channel thermal noise. In nMOSFETs, up to 10 Mrad(SiO2), the experimental behavior is consistent with a damage mechanism mainly associ- ated with lateral isolation oxides, and can be modeled by parasitic transistors turning on after irradiation and contributing to the total noise of the device. At very high dose, these parasitic transistors tend to be turned off by negative charge accumulating in interface states and compensating radiation-induced positive charge building up inside thick isolation oxides. Effects associated with ionization and hydrogen transport in spacer oxides may become dominant at 600 Mrad(SiO2) and may explain the observed noise behavior at extremely high TID. The results of this analysis provide an understanding o...

  15. SELECTED PROBLEMS OF PROTECTION AGAINST ROAD TRAFFIC NOISE

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2015-11-01

    Full Text Available The paper presents factors for assessment of road traffic noise level and possible actions towards the minimization of excessive noise in the roadway neighborhood. Changes of equivalent sound level values were analyzed in relation to traffic intensity, categorization and vehicles speed. In relation to measures reducing noise level in roadway’s surroundings particular attention was given to anti-noise protections and tyre/noise reduction. Acoustic effectiveness of specific solutions was showed based on chosen examples. It was proved that when admissible noise level is slightly exceeded the need for noise barrier use may be replaced by a proper design and maintenance of road pavement or by enforcement of speed limit.

  16. Thermally assisted OSL application for equivalent dose estimation; comparison of multiple equivalent dose values as well as saturation levels determined by luminescence and ESR techniques for a sedimentary sample collected from a fault gouge

    Energy Technology Data Exchange (ETDEWEB)

    Şahiner, Eren, E-mail: sahiner@ankara.edu.tr; Meriç, Niyazi, E-mail: meric@ankara.edu.tr; Polymeris, George S., E-mail: gspolymeris@ankara.edu.tr

    2017-02-01

    Highlights: • Multiple equivalent dose estimations were carried out. • Additive ESR and regenerative luminescence were applied. • Preliminary SAR results employing TA-OSL signal were discussed. • Saturation levels of ESR and luminescence were investigated. • IRSL{sub 175} and SAR TA-OSL stand as very promising for large doses. - Abstract: Equivalent dose estimation (D{sub e}) constitutes the most important part of either trap-charge dating techniques or dosimetry applications. In the present work, multiple, independent equivalent dose estimation approaches were adopted, using both luminescence and ESR techniques; two different minerals were studied, namely quartz as well as feldspathic polymineral samples. The work is divided into three independent parts, depending on the type of signal employed. Firstly, different D{sub e} estimation approaches were carried out on both polymineral and contaminated quartz, using single aliquot regenerative dose protocols employing conventional OSL and IRSL signals, acquired at different temperatures. Secondly, ESR equivalent dose estimations using the additive dose procedure both at room temperature and at 90 K were discussed. Lastly, for the first time in the literature, a single aliquot regenerative protocol employing a thermally assisted OSL signal originating from Very Deep Traps was applied for natural minerals. Rejection criteria such as recycling and recovery ratios are also presented. The SAR protocol, whenever applied, provided with compatible D{sub e} estimations with great accuracy, independent on either the type of mineral or the stimulation temperature. Low temperature ESR signals resulting from Al and Ti centers indicate very large D{sub e} values due to bleaching in-ability, associated with large uncertainty values. Additionally, dose saturation of different approaches was investigated. For the signal arising from Very Deep Traps in quartz saturation is extended almost by one order of magnitude. It is

  17. A study of the effect of flight density and background noise on V/STOL acceptability. [effective perceived noise level as measure of annoyance

    Science.gov (United States)

    Sternfeld, H., Jr.; Hinterkeuser, E. G.; Hackman, R. B.; Davis, J.

    1974-01-01

    A study was conducted in which test subjects evaluated the sounds of a helicopter, a turbofan STOL and a turbojet airplane while engaged in work and leisure activities. Exposure to a high repetitive density of the aircraft sounds did not make the individual sounds more annoying but did create an unacceptable environment. The application of a time duration term to db(A) resulted in a measure which compared favorably with EPNL as a predictor of annoyance. Temporal variations in background noise level had no significant effect on the rated annoyance.

  18. Arterial indices and serum cystatin C level in individuals with occupational wide band noise exposure

    Directory of Open Access Journals (Sweden)

    Ali R Khoshdel

    2016-01-01

    Full Text Available Background: Chronic exposure to noise is known to cause a wide range of health problems including extracellular matrix (ECM proliferation and involvement of cardiovascular system. There are a few studies to investigate noise-induced vascular changes using noninvasive methods. In this study we used carotid artery intima-media thickness (CIMT and aortic augmentation as indices of arterial properties and cystatin C as a serum biomarker relating to ECM metabolism. Materials and Methods: Ninety-three male participants were included in this study from aeronautic technicians: 39 with and 54 without a history of wide band noise (WBN exposure. For better discrimination, the participants were divided into the two age groups: 40 years old. Adjusted aortic augmentation index (AI for a heart rate equal to 75 beats per minute (AIx@HR75 were calculated using pulse wave analysis (PWA. CIMT was measured in 54 participants who accepted to undergo Doppler ultrasonography. Serum cystatin C was also measured. Results: Among younger individuals the mean CIMT was 0.85 ± 0.09 mm and 0.75 ± 0.22 mm in the in the exposed and the control groups respectively. Among older individuals CIMT had a mean of 1.04 ± 0.22 mm vs. 1.00 ± 0.25 mm for the exposed vs. the control group. However, in both age groups the difference was not significant at the 0.05 level. A comparison of AIx@HR75 between exposure group and control group both in younger age group (5.46 ± 11.22 vs. 8.56 ± 8.66 and older age group (17.55 ± 10.07 vs. 16.61 ± 5.77 revealed no significant difference. We did not find any significant correlation between CIMT and AIx@HR75 in exposed group (r = 0.314, P value = 0.145 but the correlation was significant in control group (r = 0.455, P value = 0.019. Serum cystatin C level was significantly lower in individuals with WBN exposure compared to controls (441.10 ± 104.70 ng/L vs. 616.89 ± 136.14, P

  19. On the Impact of Anomalous Noise Events on Road Traffic Noise Mapping in Urban and Suburban Environments.

    Science.gov (United States)

    Orga, Ferran; Alías, Francesc; Alsina-Pagès, Rosa Ma

    2017-12-23

    Noise pollution is a critical factor affecting public health, the relationship between road traffic noise (RTN) and several diseases in urban areas being especially disturbing. The Environmental Noise Directive 2002/49/EC and the CNOSSOS-EU framework are the main instruments of the European Union to identify and combat noise pollution, requiring Member States to compose and publish noise maps and noise management action plans every five years. Nowadays, the noise maps are starting to be tailored by means of Wireless Acoustic Sensor Networks (WASN). In order to exclusively monitor the impact of RTN on the well-being of citizens through WASN-based approaches, those noise sources unrelated to RTN denoted as Anomalous Noise Events (ANEs) should be removed from the noise map generation. This paper introduces an analysis methodology considering both Signal-to-Noise Ratio (SNR) and duration of ANEs to evaluate their impact on the A-weighted equivalent RTN level calculation for different integration times. The experiments conducted on 9 h of real-life data from the WASN-based DYNAMAP project show that both individual high-impact events and aggregated medium-impact events bias significantly the equivalent noise levels of the RTN map, making any derived study about public health impact inaccurate.

  20. Urban Noise Modelling in Boka Kotorska Bay

    Directory of Open Access Journals (Sweden)

    Aleksandar Nikolić

    2014-04-01

    Full Text Available Traffic is the most significant noise source in urban areas. The village of Kamenari in Boka Kotorska Bay is a site where, in a relatively small area, road traffic and sea (ferry traffic take place at the same time. Due to the specificity of the location, i.e. very rare synergy of sound effects of road and sea traffic in the urban area, as well as the expressed need for assessment of noise level in a simple and quick way, a research was conducted, using empirical methods and statistical analysis methods, which led to the creation of acoustic model for the assessment of equivalent noise level (Leq. The developed model for noise assessment in the Village of Kamenari in Boka Kotorska Bay quite realistically provides data on possible noise levels at the observed site, with very little deviations in relation to empirically obtained values.

  1. Acceptance noise level: effects of the speech signal, babble, and listener language.

    Science.gov (United States)

    Shi, Lu-Feng; Azcona, Gabrielly; Buten, Lupe

    2015-04-01

    The acceptable noise level (ANL) measure has gained much research/clinical interest in recent years. The present study examined how the characteristics of the speech signal and the babble used in the measure may affect the ANL in listeners with different native languages. Fifteen English monolingual, 16 Russian-English bilingual, and 24 Spanish-English bilingual listeners participated. The ANL was obtained in eight conditions varying in the language of the signal (English and Spanish), language of the babble (English and Spanish), and number of talkers in the babble (4 and 12). Test conditions were randomized across listeners. The ANL for each condition was based on a minimum of two trials. Russian-English bilinguals yielded higher ANLs than other listeners; the intergroup difference of 4-5 dB was statistically and clinically significant. Spanish signals yielded significantly higher ANLs than English signals, but this difference of 0.5 dB was clinically negligible. The language and composition of the babble had a significant effect on Russian-English bilinguals, who yielded higher ANLs with the Spanish than English 12-talker babble. The above findings do not fully support the notion that the ANL is language- and population-independent. Clinicians should be aware of possible effects on ANL measures due to listeners' linguistic/cultural background.

  2. Noise annoyance from stationary sources: Relationships with exposure metric day-evening-night level (DENL) and their confidence intervals

    NARCIS (Netherlands)

    Miedema, H.M.E.; Vos, H.

    2004-01-01

    Relationships between exposure to noise [metric: day-evening-night levels (DENL)] from stationary sources (shunting yards, a seasonal industry, and other industries) and annoyance are presented. Curves are presented for expected annoyance score, the percentage "highly annoyed" (%HA, cutoff at 72 on

  3. Choosing channel quantization levels and viterbi decoding for space diversity reception over the additive white Guassian noise channel

    Science.gov (United States)

    Kalson, S.

    1986-01-01

    Previous work in the area of choosing channel quantization levels for a additive white Gaussian noise channel composed of one receiver-demodulator is reviewed, and how this applies to the Deep Space Network composed of several receiver-demodulators (space diversity reception) is shown. Viterbi decoding for the resulting quantized channel is discussed.

  4. BPW34 Commercial p-i-n Diodes for High-Level 1-MeV Neutron Equivalent Fluence Monitoring

    CERN Document Server

    Ravotti, F; Moll, M; Saigne, F

    2008-01-01

    The BPW34 p-i-n diode was characterized at CERN in view of its utilization as radiation monitor at the LHC to cover the broad 1-MeV neutron equivalent fluence (Phieq) range expected for the LHC machine and experiments during operation. Electrical measurements for both forward and reverse bias were used to characterize the device and to understand its behavior under irradiation. When the device is powered forward, a sensitivity to fast hadrons for Phieq > 2 times1012 cm-2 has been observed. With increasing particle fluences the forward I- V characteristics of the diode shifts towards higher voltages. At Phieq > 3times1013 cm-2, the forward characteristic starts to bend back assuming a thyristor-like behavior. An explanation for this phenomenon is given in this article. Finally, detailed radiation-response curves for the forward bias-operation and annealing studies of the diode's forward voltage are presented for proton, neutron and gamma irradiation.

  5. Gyrokinetic equivalence

    International Nuclear Information System (INIS)

    Parra, Felix I; Catto, Peter J

    2009-01-01

    We compare two different derivations of the gyrokinetic equation: the Hamiltonian approach in Dubin D H E et al (1983 Phys. Fluids 26 3524) and the recursive methodology in Parra F I and Catto P J (2008 Plasma Phys. Control. Fusion 50 065014). We prove that both approaches yield the same result at least to second order in a Larmor radius over macroscopic length expansion. There are subtle differences in the definitions of some of the functions that need to be taken into account to prove the equivalence.

  6. Comparison of clinical parameters and environmental noise levels between regular surgery and piezosurgery for extraction of impacted third molars.

    Science.gov (United States)

    Chang, Hao-Hueng; Lee, Ming-Shu; Hsu, You-Chyun; Tsai, Shang-Jye; Lin, Chun-Pin

    2015-10-01

    Impacted third molars can be extracted by regular surgery or piezosurgery. The aim of this study was to compare clinical parameters and device-produced noise levels between regular surgery and piezosurgery for the extraction of impacted third molars. Twenty patients (18 women and 2 men, 17-29 years of age) with bilateral symmetrical impacted mandibular or maxillary third molars of the same level were included in this randomized crossover clinical trial. The 40 impacted third molars were divided into a control group (n = 20), in which the third molar was extracted by regular surgery using a high-speed handpiece and an elevator, and an experimental group (n = 20), in which the third molar was extracted by piezosurgery using a high-speed handpiece and a piezotome. The clinical parameters were evaluated by a self-reported questionnaire. The noise levels produced by the high-speed handpiece and piezotome were measured and compared between the experimental and control groups. Patients in the experimental group had a better feeling about tooth extraction and force delivery during extraction and less facial swelling than patients in the control group. However, there were no significant differences in noise-related disturbance, extraction period, degree of facial swelling, pain score, pain duration, any noise levels produced by the devices under different circumstances during tooth extraction between the control and experimental groups. The piezosurgery device produced noise levels similar to or lower than those of the high-speed drilling device. However, piezosurgery provides advantages of increased patient comfort during extraction of impacted third molars. Copyright © 2014. Published by Elsevier B.V.

  7. Reorganization of auditory map and pitch discrimination in adult rats chronically exposed to low-level ambient noise

    Directory of Open Access Journals (Sweden)

    Weimin eZheng

    2012-09-01

    Full Text Available Behavioral adaption to a changing environment is critical for an animal’s survival. How well the brain can modify its functional properties based on experience essentially defines the limits of behavioral adaptation. In adult animals the extent to which experience shapes brain function has not been fully explored. Moreover, the perceptual consequences of experience-induced changes in the brains of adults remain unknown. Here we show that the tonotopic map in the primary auditory cortex of adult rats living with low-level ambient noise underwent a dramatic reorganization. Behaviorally, chronic noise-exposure impaired fine, but not coarse pitch discrimination. When tested in a noisy environment, the noise-exposed rats performed as well as in a quiet environment whereas the control rats performed poorly. This suggests that noise-exposed animals had adapted to living in a noisy environment. Behavioral pattern analyses revealed that stress or distraction engendered by the noisy background could not account for the poor performance of the control rats in a noisy environment. A reorganized auditory map may therefore have served as the neural substrate for the consistent performance of the noise-exposed rats in a noisy environment.

  8. [Evaluation of strategies aimed at reducing the level of noise in different areas of neonatal care in a tertiary hospital].

    Science.gov (United States)

    Nieto-Sanjuanero, Adriana; Quero-Jiménez, José; Cantú-Moreno, Daniel; Rodríguez-Balderrama, Isaías; Montes-Tapia, Fernando; Rubio-Pérez, Nadina; Treviño-Garza, Consuelo; de la O-Cavazos, Manuel

    2015-01-01

    To determine the noise levels of different areas responsible for newborn care, develop intervention strategies to decrease the noise, and evaluate its effectiveness. Prospective, observational and longitudinal study carried out using a sonometer, measuring sound levels for three weeks in the neonatal intensive care unit (NICU), neonatal intermediate care unit (UCIREN), delivery (TOCO QX) and nursery (CUNERO) units. We implemented an intervention program and subsequent measurements were performed under the same initial conditions. When comparing the decibel levels in different areas during the three weeks, pre- and post-intervention, we found at the neonatal intensive care unit 59.9±4.8 vs. 56.4±4.7 dB (pTOCO QX, so the intervention program was effective in these areas; however, the decibel levels registered continue above those recommended by international standards.

  9. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study

    DEFF Research Database (Denmark)

    Bouserhal, Rachel E.; MacDonald, Ewen; Falk, Tiago H.

    2016-01-01

    in voice level and fundamental frequency in noise and with varying talker-to-listener distance. Study sample: Twelve participants with a mean age of 28 participated in this study. Results: Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded...

  10. Comparison of clinical parameters and environmental noise levels between regular surgery and piezosurgery for extraction of impacted third molars

    OpenAIRE

    Chang, Hao-Hueng; Lee, Ming-Shu; Hsu, You-Chyun; Tsai, Shang-Jye; Lin, Chun-Pin

    2015-01-01

    Impacted third molars can be extracted by regular surgery or piezosurgery. The aim of this study was to compare clinical parameters and device-produced noise levels between regular surgery and piezosurgery for the extraction of impacted third molars. Methods: Twenty patients (18 women and 2 men, 17–29 years of age) with bilateral symmetrical impacted mandibular or maxillary third molars of the same level were included in this randomized crossover clinical trial. The 40 impacted third molar...

  11. Deaf Smith County noise analysis: Revision 2

    International Nuclear Information System (INIS)

    1985-11-01

    An analysis of activities proposed for the three major phases of development of the proposed nuclear waste repository site in Deaf Smith County, Texas, was conducted to quantify the noise levels and the effect of noise resulting from these activities. The report provides additional details of the predictive noise level modeling conducted for the site characterization, repository construction, and repository operation phases. Equivalent day/night sound levels are presented for each phase as sound level contours. Sound levels from onsite and offsite activities are addressed including traffic on access routes, and railroad construction and operation. A description of the predictive models, the analysis methodologies, the noise source inventories, the model outputs, and the evaluation criteria are included. 35 refs., 6 figs., 2 tabs

  12. Characterization of noise in different industrial workstations

    Science.gov (United States)

    Correia, Aldina; Lopes, Miguel; de Almeida, M. Fátima

    2017-11-01

    The damage caused by noise in workers' health is well known. The European Agency for Safety and Health at Work presented in 2005 a summary of main effects of workplace noise, defining the loss of hearing as the principal effect of noise exposure, however, it can also exacerbate stress and increase the risk of accidents. The problem to be addressed is this work is about noise analysis, performed under the PREVENIR program. The data was collected in industrial workplaces from 280 Portuguese industrial companies distributed by different sectors. The program was implemented between 2005 and 2011. The aim of this work is identify differences of intensity of noise exposure between these industrial sectors in different workplaces, using inference techniques. The existence of significance differences between average levels of Equivalent Sound Level (LAeq,TdB(A)) are verified using ANOVA.

  13. Screening-level Biomonitoring Equivalents for tiered interpretation of urinary 3-phenoxybenzoic acid (3-PBA) in a risk assessment context.

    Science.gov (United States)

    Aylward, Lesa L; Irwin, Kim; St-Amand, Annie; Nong, Andy; Hays, Sean M

    2018-02-01

    3-Phenoxybenzoic acid (3-PBA) is a common metabolite of several pyrethroid pesticides of differing potency and also occurs as a residue in foods resulting from environmental degradation of parent pyrethroid compounds. Thus, 3-PBA in urine is not a specific biomarker of exposure to a particular pyrethroid. However, an approach derived from the use of Biomonitoring Equivalents (BEs) can be used to estimate a conservative initial screening value for a tiered assessment of population data on 3-PBA in urine. A conservative generic urinary excretion fraction for 3-PBA was estimated from data for five pyrethroid compounds with human data. Estimated steady-state urinary 3-PBA concentrations associated with reference doses and acceptable daily intakes for each of the nine compounds ranged from 1.7 μg/L for cyhalothrin and deltamethrin to 520 μg/L for permethrin. The lower value can be used as a highly conservative Tier 1 screening value for assessment of population urinary 3-PBA data. A second tier screening value of 87 μg/L was derived based on weighting by relative exposure estimates for the different pyrethroid compounds, to be applied as part of the data evaluation process if biomonitoring data exceed the Tier 1 value. These BE values are most appropriately used to evaluate the central tendency of population biomarker concentration data in a risk assessment context. The provisional BEs were compared to available national biomonitoring data from the US and Canada. Copyright © 2017. Published by Elsevier Inc.

  14. Traffic Noise Assessment at Residential Areas in Skudai, Johor

    Science.gov (United States)

    Sulaiman, F. S.; Darus, N.; Mashros, N.; Haron, Z.; Yahya, K.

    2018-03-01

    Vehicles passing by on roadways in residential areas may produce unpleasant traffic noise that affects the residents. This paper presents the traffic noise assessment of three selected residential areas located in Skudai, Johor. The objectives of this study are to evaluate traffic characteristics at selected residential areas, determine related noise indices, and assess impact of traffic noise. Traffic characteristics such as daily traffic volume and vehicle speed were evaluated using automatic traffic counter (ATC). Meanwhile, noise indices like equivalent continuous sound pressure level (LAeq), noise level exceeded 10% (L10) and 90% (L90) of measurement time were determined using sound level meter (SLM). Besides that, traffic noise index (TNI) and noise pollution level (LNP) were calculated based on the measured noise indices. The results showed an increase in noise level of 60 to 70 dBA maximum due to increase in traffic volume. There was also a significant change in noise level of more than 70 dBA even though average vehicle speed did not vary significantly. Nevertheless, LAeq, TNI, and LNP values for all sites during daytime were lower than the maximum recommended levels. Thus, residents in the three studied areas were not affected in terms of quality of life and health.

  15. Recommendation of maximum allowable noise levels for offshore wind power systems; Empfehlung von Laermschutzwerten bei der Errichtung von Offshore-Windenergieanlagen (OWEA)

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Stefanie [Umweltbundesamt, Dessau-Rosslau (Germany). Fachgebiet II 2.3

    2011-05-15

    When offshore wind farms are constructed, every single pile is hammered into the sediment by a hydraulic hammer. Noise levels at Horns Reef wind farm were in the range of 235 dB. The noise may cause damage to the auditory system of marine mammals. The Federal Environmental Office therefore recommends the definition of maximum permissible noise levels. Further, care should be taken that no marine mammals are found in the immediate vicinity of the construction site. (AKB)

  16. Equivalent threshold sound pressure levels (ETSPL) for Sennheiser HDA 280 supra-aural audiometric earphones in the frequency range 125 Hz to 8000 Hz

    DEFF Research Database (Denmark)

    Poulsen, Torben; Oakley, Sebastian

    2009-01-01

    Hearing threshold sound pressure levels were measured for the Sennheiser HDA 280 audiometric earphone. Hearing thresholds were measured for 25 normal hearing test subjects at the 11 audiometric test frequencies from 125 Hz to 8000 Hz. Sennheiser HDA 280 is a supra-aural earphone that may be seen...... as a substitute for the classical Telephonics TDH 39. The results are given as the Equivalent Threshold Sound Pressure Level, ETSPL, measured in an acoustic coupler specified in IEC 60318-3. The results are in good agreement with an independent investigation from PTB, Braunschweig, Germany. From acoustic...

  17. Cochlea hair cell rescue after a noise-induced hearing loss using a low level laser therapy (LLLT)

    Science.gov (United States)

    Rhee, Chung-Ku; Bahk, Chan Woong; Jung, Jae Yun; Ahn, Jin-Chul; Suh, Myung-Whan

    2011-03-01

    Aim: To see the effect of LLLT on noise-induced hearing loss. Methods: Eleven rats were exposed to noise (120 dB, 16 kHz, 6 h) and left ears were irradiated at 60J/cm2, 830 nm laser for 12 days. Right ears were control. Hearing levels were measured at frequencies of 4, 8, 12, 16, 32 kHz before noise exposure and after 12th irradiations. Results: The initial hearing levels were 26.5+/-4.7, 24.5+/-5.0, 24.0+/-5.2, 24.0+/-3.2, 24.5+/-5.5 dB SPL. After noise exposure, thresholds were 63.5+/-15.1, 64+/-16.8, 71.5+/-11.3, 73.5+/-15.6, 67.5+/-14.4 dB SPL in 4, 8, 12, 16, 32 kHz. After 12th irradiation, thresholds of treated ears recovered significantly 21+/-4.2, 20+/-3.5, 24+/-11.9, 24+/-12.9, 21+/-2.2 dB SPL and that of the untreated right ears measured 36.3+/-22.9, 45+/-15.8, 66.3+/-22.9, 50+/-16.8, 43.8+/-21.4 dB SPL. Conclusion: LLLT may promote recovery of hearing after noiseinduced hearing loss.

  18. Continuous monitoring of noise levels in the Gulf of Catania (Ionian Sea). Study of correlation with ship traffic.

    Science.gov (United States)

    Viola, S; Grammauta, R; Sciacca, V; Bellia, G; Beranzoli, L; Buscaino, G; Caruso, F; Chierici, F; Cuttone, G; D'Amico, A; De Luca, V; Embriaco, D; Favali, P; Giovanetti, G; Marinaro, G; Mazzola, S; Filiciotto, F; Pavan, G; Pellegrino, C; Pulvirenti, S; Simeone, F; Speziale, F; Riccobene, G

    2017-08-15

    Acoustic noise levels were measured in the Gulf of Catania (Ionian Sea) from July 2012 to May 2013 by a low frequency (<1000Hz) hydrophone, installed on board the NEMO-SN1 multidisciplinary observatory. NEMO-SN1 is a cabled node of EMSO-ERIC, which was deployed at a water depth of 2100m, 25km off Catania. The study area is characterized by the proximity of mid-size harbors and shipping lanes. Measured noise levels were correlated with the passage of ships tracked with a dedicated AIS antenna. Noise power was measured in the frequency range between 10Hz and 1000Hz. Experimental data were compared with the results of a fast numerical model based on AIS data to evaluate the contribution of shipping noise in six consecutive 1/3 octave frequency bands, including the 1/3 octave frequency bands centered at 63Hz and 125Hz, indicated by the Marine Strategy Framework Directive (2008/56/EC). Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. A descriptive study of noise in the neonatal intensive care unit: ambient levels and perceptions of contributing factors.

    Science.gov (United States)

    Darcy, Ashley E; Hancock, Lauren E; Ware, Emily J

    2008-10-01

    To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs. Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs. This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise. Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels. Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones. Noise levels were found to be above the American Academy of Pediatrics-recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated

  20. A descriptive study of noise in the neonatal intensive care unit. Ambient levels and perceptions of contributing factors.

    Science.gov (United States)

    Darcy, Ashley E; Hancock, Lauren E; Ware, Emily J

    2008-06-01

    To examine the baseline acoustic environment in several mid-Atlantic region neonatal intensive care units (NICUs) and investigate the perceived factors contributing to noise levels in these NICUs. Quantitative data were collected from 3 urban, mid-Atlantic level IIIB and level IIIC NICUs. Qualitative data were collected via interview from 2 RNs employed in each of the study NICUs. This was an exploratory descriptive study utilizing a mixed-methods approach. A quantitative method was used for sound-level data collection, and a qualitative method was utilized during interviews with nurses to examine perceptions of factors contributing to noise. Ambient sound levels, measured in decibels, were taken at 5-minute intervals over a 2-hour period during both day and night shifts in a central location at each NICU. In addition, nurses were interviewed using a standardized interview questionnaire, and these interviews were then reviewed to determine themes regarding perceived factors contributing to sound levels. Hourly mean sound levels in each NICU ranged from 53.9 dB to 60.6 dB, with no statistically significant difference between noise levels recorded on day shift versus night shift, and no statistically significant difference among sites. Qualitative data showed that nurses' believed day shift to be louder than night shift and many perceived their own NICU as "pretty quiet." Key contributing factors to increased sound levels were stated as monitors or alarms, performing invasive procedures, presence of family, nurses or doctors giving report or rounds, and ringing phones. Noise levels were found to be above the American Academy of Pediatrics--recommended 45-dB level and often louder than the 50-dB level, which should not be exceeded more than 10% of the time. The recommended impulse maximum of 65 dB was also exceeded. Environmental Protection Agency recommendations for hospitals include sound levels no louder than 35 dB on night shift; this standard was also violated

  1. Audible Noise Measurement and Analysis of the Main Power Apparatus in UHV GIS Substations

    Directory of Open Access Journals (Sweden)

    Zhou Nian Guang

    2016-01-01

    Full Text Available Investigation of audible noise characteristics of the main power apparatus in UHV GIS substations provides essential statistics for the noise prediction and control. Noise pressure level, spectrum and attenuation characteristics of the main transformers and high voltage (HV reactors are measured and analyzed in this paper. The result shows that the main transformer and HV reactor have identical A-weighted equivalent sound pressure level. The medium- and low-frequency noises are the primary components in the spectral. More attention should be paid to the low-frequency bands in the noise control process. The noise of cooling fan has a large influence on that of the main transformer. Without the consideration of corona noise, the average A-weighted sound pressure level shows an overall decreasing trend with the increase of the propagation distance. Obvious interference phenomenon of the noises at 100 and 200Hz exists in the noise propagation process.

  2. Investigation into the Dependence of Noise Generated By Standing Cars on the Engine Power

    Directory of Open Access Journals (Sweden)

    Julius Gineika

    2012-12-01

    Full Text Available Ambient noise harms a number of citizens in Europe. The major sources of environmental noise are that generated by cars in streets, parking lots, railway lines and airports as well as noise from local sources (fans, transformers. According to the methodology for noise measurement, engine testing has been carried out. The conducted analysis has been focused on engine capacity and the distance between vehicles and equipment. Equivalent, maximum and minimum sound levels at different frequencies have been measured accepting that errors may range up to 2 %. Maximum sound level has been reached using the engine of 2000 cm3 petrol capacity. At a half-meter distance, the equivalent sound level reaches 89 dB(A, whereas the noise level decreases moving away from the car. The obtained results of tested cars disclose that according to engine capacity, the majority of the investigated cars are technically faulty and therefore significantly exceed noise levels.Article in Lithuanian

  3. Noise level arrangement in determined zones of homogenous development of green areas on the example of the spa park in Inowrocław

    Science.gov (United States)

    Sztubecka, Małgorzata; Skiba, Marta

    2016-11-01

    Noise measurements are usually carried out in developed areas as well as in the surroundings of traffic routes providing basis for actions in order to limit its influence on the neighboring areas. Noise measurements in park areas are rare due to belief that these areas are silent zones. Such attitude cannot be justified. This article aims to the assessment of noise appearing in determined subzones of the spa park in Inowrocław. From the research carried out it can be noticed that traffic noise does not have any important meaning for the acoustic climate of the park. It is the people who stay there who generate more noise. Comparative analysis proves the appearance and penetration of noise from the zones with greater level of noise to the ones with lower amount.

  4. Reduction of Air Pollution Levels Downwind of a Road with an Upwind Noise Barrier

    Science.gov (United States)

    We propose a dispersion model to characterize the impact of an upwind solid noise barrier next to a highway on air pollution concentrations downwind of the road. The model is based on data from wind tunnel experiments conducted by Heist et al. (2009). The model assumes that the...

  5. Tunneling magnetoresistance sensor with pT level 1/f magnetic noise

    Science.gov (United States)

    Deak, James G.; Zhou, Zhimin; Shen, Weifeng

    2017-05-01

    Magnetoresistive devices are important components in a large number of commercial electronic products in a wide range of applications including industrial position sensors, automotive sensors, hard disk read heads, cell phone compasses, and solid state memories. These devices are commonly based on anisotropic magnetoresistance (AMR) and giant magnetoresistance (GMR), but over the past few years tunneling magnetoresistance (TMR) has been emerging in more applications. Here we focus on recent work that has enabled the development of TMR magnetic field sensors with 1/f noise of less than 100 pT/rtHz at 1 Hz. Of the commercially available sensors, the lowest noise devices have typically been AMR, but they generally have the largest die size. Based on this observation and modeling of experimental data size and geometry dependence, we find that there is an optimal design rule that produces minimum 1/f noise. This design rule requires maximizing the areal coverage of an on-chip flux concentrator, providing it with a minimum possible total gap width, and tightly packing the gaps with MTJ elements, which increases the effective volume and decreases the saturation field of the MTJ freelayers. When properly optimized using this rule, these sensors have noise below 60 pT/rtHz, and could possibly replace fluxgate magnetometers in some applications.

  6. Noise levels in a neonatal intensive care unit in the Cape metropole

    African Journals Online (AJOL)

    2008-05-14

    May 14, 2008 ... stress for the neonate.2 Numerous published studies have ... The effects of noise on infants in the NICU have been well ... difficulties and information processing disorders at pre- and ... Division of Speech, Language and Hearing Therapy, Department of Interdisciplinary Health Sciences, Stellenbosch ...

  7. On the variances of generation-recombination noise in a three-level system

    NARCIS (Netherlands)

    Hooge, F.N.; Ren, L.

    1994-01-01

    A statistical treatment is given of the generation-recombination noise in a semiconductor with a conduction band and two traps X and Y. The system is described in terms of x and y, where x is half the harmonic mean of the numbers of occupied and empty traps X. A corresponding definition is given for

  8. Recent and long-term occupational noise exposure and salivary cortisol level

    DEFF Research Database (Denmark)

    Stokholm, Zara Ann; Hansen, Åse Marie; Grynderup, Matias Brødsgaard

    2014-01-01

    Environmental and occupational noise exposure have been related to increased risk of cardiovascular disease, hypothetically mediated by stress-activation of the hypothalamic-pituitary-adrenal (HPA) axis. The objective of this study was to investigate the relation between recent and long-term occu...

  9. External noise distinguishes attention mechanisms.

    Science.gov (United States)

    Lu, Z L; Dosher, B A

    1998-05-01

    We developed and tested a powerful method for identifying and characterizing the effect of attention on performance in visual tasks as due to signal enhancement, distractor exclusion, or internal noise suppression. Based on a noisy Perceptual Template Model (PTM) of a human observer, the method adds increasing amounts of external noise (white gaussian random noise) to the visual stimulus and observes the effect on performance of a perceptual task for attended and unattended stimuli. The three mechanisms of attention yield three "signature" patterns of performance. The general framework for characterizing the mechanisms of attention is used here to investigate the attentional mechanisms in a concurrent location-cued orientation discrimination task. Test stimuli--Gabor patches tilted slightly to the right or left--always appeared on both the left and the right of fixation, and varied independently. Observers were cued on each trial to attend to the left, the right, or evenly to both stimuli, and decide the direction of tilt of both test stimuli. For eight levels of added external noise and three attention conditions (attended, unattended, and equal), subjects' contrast threshold levels were determined. At low levels of external noise, attention affected threshold contrast: threshold contrasts for non-attended stimuli were systematically higher than for equal attention stimuli, which were, in turn, higher than for attended stimuli. Specifically, when the rms contrast of the external noise is below 10%, there is a consistent 17% elevation of contrast threshold from attended to unattended condition across all three subjects. For higher levels of external noise, attention conditions did not affect threshold contrast values at all. These strong results are characteristic of a signal enhancement, or equivalently, an internal additive noise reduction mechanism of attention.

  10. The Feasibility of Noise Control in a Soft Drink Plant

    Directory of Open Access Journals (Sweden)

    Fouladi Dehaghi

    2016-03-01

    Full Text Available Background “Noise” can be defined as any unwanted sound. Soft drink plants, which produce the raw materials used in most carbonated beverage factories, are sources of noise. Objectives This study investigated the noise pollution present in a soft drink CO2 gas injection plant, in order to present noise control measures. Materials and Methods The instructions specified by the canadian center for occupational health and safety (CCOHS were followed during the noise study, and a sound level meter, CEL.450 calibrated with CEL-110.2 based on ISO-9612 methods, was used to record the sound pressure level (SPL at each grid point. SPL was determined in weighting scales A and C. and a noise survey map of equivalent SPLs was drawn for each part. Each part of the floor area of the soft drink factory where SPL exceeded 85 dBA was identified from the noise survey map to determine the causes of high levels of noise. In order to reduce noise level in each part, the absorption coefficient, transmission loss, and noise reduction rate were calculated in the proposed control area. Results According to the study results, noise levels in a CO2 plant’s house and control room ranged from 88 to 102 dB and 79 to 82 dB (A, respectively. In order to reduce the amount of emitted noise in the CO2 plant house and control room, a noise control plan was implemented in each part of the facility; it was met with effective results. Conclusions The findings of this investigation have clearly revealed that plant workers are at risk of developing noise-induced hearing loss. However, after the implementation of a noise control plan in each part of the facility, the noise dose received by workers has significantly decreased. The need to implement a noise conservation program was established.

  11. Research on maximum level noise contaminated of remote reference magnetotelluric measurements using synthesized data

    Science.gov (United States)

    Gang, Zhang; Fansong, Meng; Jianzhong, Wang; Mingtao, Ding

    2018-02-01

    Determining magnetotelluric impedance precisely and accurately is fundamental to valid inversion and geological interpretation. This study aims to determine the minimum value of signal-to-noise ratio (SNR) which maintains the effectiveness of remote reference technique. Results of standard time series simulation, addition of different Gaussian noises to obtain the different SNR time series, and analysis of the intermediate data, such as polarization direction, correlation coefficient, and impedance tensor, show that when the SNR value is larger than 23.5743, the polarization direction disorder at morphology and a smooth and accurate sounding carve value can be obtained. At this condition, the correlation coefficient value of nearly complete segments between the base and remote station is larger than 0.9, and impedance tensor Zxy presents only one aggregation, which meet the natural magnetotelluric signal characteristic.

  12. Judgments of aircraft noise in a traffic noise background

    Science.gov (United States)

    Powell, C. A.; Rice, C. G.

    1975-01-01

    An investigation was conducted to determine subjective response to aircraft noise in different road traffic backgrounds. In addition, two laboratory techniques for presenting the aircraft noise with the background noise were evaluated. For one technique, the background noise was continuous over an entire test session; for the other, the background noise level was changed with each aircraft noise during a session. Subjective response to aircraft noise was found to decrease with increasing background noise level, for a range of typical indoor noise levels. Subjective response was found to be highly correlated with the Noise Pollution Level (NPL) measurement scale.

  13. The association between low levels of lead in blood and occupational noise-induced hearing loss in steel workers

    International Nuclear Information System (INIS)

    Hwang, Yaw-Huei; Chiang, Han-Yueh; Yen-Jean, Mei-Chu; Wang, Jung-Der

    2009-01-01

    As the use of leaded gasoline has ceased in the last decade, background lead exposure has generally been reduced. The aim of this study was to examine the effect of low-level lead exposure on human hearing loss. This study was conducted in a steel plant and 412 workers were recruited from all over the plant. Personal information such as demographics and work history was obtained through a questionnaire. All subjects took part in an audiometric examination of hearing thresholds, for both ears, with air-conducted pure tones at frequencies of 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz. Subjects' blood samples were collected and analyzed for levels of manganese, copper, zinc, arsenic, cadmium and lead with inductive couple plasma-mass spectrometry. Meanwhile, noise levels in different working zones were determined using a sound level meter with A-weighting network. Only subjects with hearing loss difference of no more than 15 dB between both ears and had no congenital abnormalities were included in further data analysis. Lead was the only metal in blood found significantly correlated with hearing loss for most tested sound frequencies (p < 0.05 to p < 0.0001). After adjustment for age and noise level, the logistic regression model analysis indicated that elevated blood lead over 7 μg/dL was significantly associated with hearing loss at the sound frequencies of 3000 through 8000 Hz with odds ratios raging from 3.06 to 6.26 (p < 0.05 ∼ p < 0.005). We concluded that elevated blood lead at level below 10 μg/dL might enhance the noise-induced hearing loss. Future research needs to further explore the detailed mechanism.

  14. The association between low levels of lead in blood and occupational noise-induced hearing loss in steel workers

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yaw-Huei [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Chiang, Han-Yueh [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Yen-Jean, Mei-Chu [Division of Family Medicine, E-Da Hospital, Taiwan, ROC 1, E-Da Rd., Jiau-Shu Tsuen, Yan-Chau Shiang, Kaohsiung County, Taiwan, ROC (China); I-Shou University, Kaohsiung County, Taiwan, ROC 1, Sec. 1, Syuecheng Rd., Da-Shu Shiang, Kaohsiung County, Taiwan, ROC (China); Wang, Jung-Der, E-mail: jdwang@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan, ROC Rm. 735, 17, Xu-Zhou Rd., Taipei, Taiwan, ROC (China); Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan, ROC No. 1, Chang-Teh St., Taipei, Taiwan, ROC (China)

    2009-12-15

    As the use of leaded gasoline has ceased in the last decade, background lead exposure has generally been reduced. The aim of this study was to examine the effect of low-level lead exposure on human hearing loss. This study was conducted in a steel plant and 412 workers were recruited from all over the plant. Personal information such as demographics and work history was obtained through a questionnaire. All subjects took part in an audiometric examination of hearing thresholds, for both ears, with air-conducted pure tones at frequencies of 500, 1000, 2000, 3000, 4000, 6000 and 8000 Hz. Subjects' blood samples were collected and analyzed for levels of manganese, copper, zinc, arsenic, cadmium and lead with inductive couple plasma-mass spectrometry. Meanwhile, noise levels in different working zones were determined using a sound level meter with A-weighting network. Only subjects with hearing loss difference of no more than 15 dB between both ears and had no congenital abnormalities were included in further data analysis. Lead was the only metal in blood found significantly correlated with hearing loss for most tested sound frequencies (p < 0.05 to p < 0.0001). After adjustment for age and noise level, the logistic regression model analysis indicated that elevated blood lead over 7 {mu}g/dL was significantly associated with hearing loss at the sound frequencies of 3000 through 8000 Hz with odds ratios raging from 3.06 to 6.26 (p < 0.05 {approx} p < 0.005). We concluded that elevated blood lead at level below 10 {mu}g/dL might enhance the noise-induced hearing loss. Future research needs to further explore the detailed mechanism.

  15. The effect of audiovisual and binaural listening on the acceptable noise level (ANL): establishing an ANL conceptual model.

    Science.gov (United States)

    Wu, Yu-Hsiang; Stangl, Elizabeth; Pang, Carol; Zhang, Xuyang

    2014-02-01

    Little is known regarding the acoustic features of a stimulus used by listeners to determine the acceptable noise level (ANL). Features suggested by previous research include speech intelligibility (noise is unacceptable when it degrades speech intelligibility to a certain degree; the intelligibility hypothesis) and loudness (noise is unacceptable when the speech-to-noise loudness ratio is poorer than a certain level; the loudness hypothesis). The purpose of the study was to investigate if speech intelligibility or loudness is the criterion feature that determines ANL. To achieve this, test conditions were chosen so that the intelligibility and loudness hypotheses would predict different results. In Experiment 1, the effect of audiovisual (AV) and binaural listening on ANL was investigated; in Experiment 2, the effect of interaural correlation (ρ) on ANL was examined. A single-blinded, repeated-measures design was used. Thirty-two and twenty-five younger adults with normal hearing participated in Experiments 1 and 2, respectively. In Experiment 1, both ANL and speech recognition performance were measured using the AV version of the Connected Speech Test (CST) in three conditions: AV-binaural, auditory only (AO)-binaural, and AO-monaural. Lipreading skill was assessed using the Utley lipreading test. In Experiment 2, ANL and speech recognition performance were measured using the Hearing in Noise Test (HINT) in three binaural conditions, wherein the interaural correlation of noise was varied: ρ = 1 (N(o)S(o) [a listening condition wherein both speech and noise signals are identical across two ears]), -1 (NπS(o) [a listening condition wherein speech signals are identical across two ears whereas the noise signals of two ears are 180 degrees out of phase]), and 0 (N(u)S(o) [a listening condition wherein speech signals are identical across two ears whereas noise signals are uncorrelated across ears]). The results were compared to the predictions made based on the

  16. Noise and room acoustic conditions in a tertiary referral hospital in Seoul, Korea

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho; Cho, Wan-Ho; Chang, Ji-ho

    2018-01-01

    Noise levels and room acoustic parameters at a tertiary referral hospital, Seoul National University Hospital in Korea, are investigated. Through a questionnaire, acoustically problematic rooms are identified. Noise levels in emergency rooms (ERs) and intensive care units (ICUs) are measured over...... level for the first night was 66 dBA, which came down to 56 dBA for the next day. The reason for the higher noise level for the first night in the ICU was frequent alarm sound and treatment noise related to a critical patient. The noise level in the measured ERs is about 10 dB lower than those measured...... about three days. Acoustically critical and problematic rooms in the otolaryngology department are measured: examination rooms, operating rooms, nurse stations, patient rooms, and audiometric rooms. The equivalent A-weighted noise level, LAeq, ranges from 54 to 56 dBA in two ERs. In an ICU, the noise...

  17. Noise suppression by noise

    OpenAIRE

    Vilar, J. M. G. (José M. G.), 1972-; Rubí Capaceti, José Miguel

    2001-01-01

    We have analyzed the interplay between an externally added noise and the intrinsic noise of systems that relax fast towards a stationary state, and found that increasing the intensity of the external noise can reduce the total noise of the system. We have established a general criterion for the appearance of this phenomenon and discussed two examples in detail.

  18. Study of noise in offices with window-type room air-conditioners

    International Nuclear Information System (INIS)

    Shaikh, G.H.; Hashmi, R.; Shareef, A.

    2005-01-01

    A Study of Noise has been carried out in 17 private offices, with window-type room air-conditioners, to assess noise levels in these offices. A-Weighted equivalent sound-pressure levels (dB(A) LAeq) and equivalent octave-band sound-pressure levels (dB Leq) were measured in each office, and Preferred Speech Interference Levels (PSIL) evaluated. The results show that the interior noise-levels in these offices vary from 59.6 to 72.2 dB(A) LAeq. which are very high and much above the interior noise limits, recommended for offices by some individual workers. Some ways and means to limit its emission of high level of noise from the air conditioners are also discussed. (author)

  19. Estimation of thyroid equivalent doses during evacuation based on body surface contamination levels in the nuclear accident of FDNPS in 2011

    Science.gov (United States)

    Ohba, Takashi; Hasegawa, Arifumi; Kohayakawa, Yoshitaka; Kondo, Hisayoshi; Suzuki, Gen

    2017-09-01

    To reduce uncertainty in thyroid dose estimation, residents' radiation protection behavior should be reflected in the estimation. Screening data of body surface contamination provide information on exposure levels during evacuation. Our purpose is to estimate thyroid equivalent doses based on body surface contamination levels using a new methodology. We obtained a record of 7,539 residents/evacuees. Geiger-Mueller survey meter measurement value in cpm was translated into Bq/cm2 according to the nuclides densities obtained by measuring clothing from two persons by germanium γ-spectrometer. The measurement value of body surface contamination on head was adjusted by a natural removal rate of 15 hours and radionuclides' physical half-life. Thyroid equivalent dose of 1-year-old children by inhalation was estimated by two-dimensional Monte Carlo simulation. The proportions of evacuees/residents with measurement value in cpm of Namie and Minamisoma groups were higher than those of other groups during both periods (p<0.01, Kruskal-Wallis). During 12-14 March period, 50 and 95 percentiles of thyroid equivalent doses by inhalation were estimated as 2.7 and 86.0 mSv, respectively, for Namie group, and 4.2 and 17.2 mSv, respectively, for Minamisoma group, 0.1 and 1.0 mSv, respectively, for Tomioka/Okuma/Futaba/Naraha group, and 0.2 and 2.1 mSv, respectively, for the other group. During 15- 17 March period, 50 and 95 percentiles of thyroid equivalent doses by inhalation were 0.8 and 15.7 mSv, respectively, for Namie group, and 1.6 and 8.4 mSv, respectively, for Minamisoma group, 0.2 and 13.2 mSv, respectively, for Tomioka/Okuma/Futaba/Naraha group, and 1.2 and 12.7 mSv, respectively, for the other group. It was indicated that inhalation dose was generally higher in Namie and Minamisoma groups during 12-14 March than those during 15-17 March might reflect different self-protective behavior to radioactive plumes from other groups.

  20. Decreased Hippocampal 5-HT and DA Levels Following Sub-Chronic Exposure to Noise Stress: Impairment in both Spatial and Recognition Memory in Male Rats.

    Science.gov (United States)

    Haider, Saida; Naqvi, Fizza; Batool, Zehra; Tabassum, Saiqa; Perveen, Tahira; Saleem, Sadia; Haleem, Darakhshan Jabeen

    2012-01-01

    Mankind is exposed to a number of stressors, and among them noise is one which can cause intense stress. High levels of background noise can severely impair one's ability to concentrate. The present study was aimed to investigate the effect of sub-chronic noise stress on cognitive behavior and hippocampal monoamine levels in male rats. The study was performed on 12 male Wistar rats, divided into two groups; the control and noise-exposed. The rats in the test group were subjected to noise stress, 4h daily for 15 days. Cognitive testing was performed by the Elevated Plus Maze test (EPM) and Novel Object Recognition test (NOR). HPLC-EC was used to determine hippocampal monoamine levels and their metabolites. The data obtained revealed a significant decrease in hippocampal serotonin (5-hydroxytryptamine; 5-HT) and dopamine (DA) levels, whereas turnover ratios of 5-HT and DA were significantly increased compared to the controls. Rats exposed to noise exhibited a significant decrement in spatial memory. A significantly decreased recognition index of rats exposed to noise as compared to the control was also observed in the NOR test. Results of the present findings suggest the role of decreased hippocampal 5-HT and DA in the impairment of cognitive function following noise exposure.

  1. On the variances of generation-recombination noise in a three-level system

    Science.gov (United States)

    Hooge, F. N.; Ren, L.

    1994-01-01

    A statistical treatment is given of the generation-recombination noise in a semiconductor with a conduction band and two traps X and Y. The system is described in terms of x and y, where x is half the harmonic mean of the numbers of occupied and empty traps X. A corresponding definition is given for y. The use of x and y makes the formalism very transparent. Simple, explicit relations are easily found, which can be further simplified by approximations depending on the ratios between N, x and y. We consider correlations and Burgess' theorem; time dependence and spectra are not discussed.

  2. The Effect of Exposure to High Noise Levels on the Performance and Rate of Error in Manual Activities.

    Science.gov (United States)

    Khajenasiri, Farahnaz; Zamanian, Alireza; Zamanian, Zahra

    2016-03-01

    Sound is among the significant environmental factors for people's health, and it has an important role in both physical and psychological injuries, and it also affects individuals' performance and productivity. The aim of this study was to determine the effect of exposure to high noise levels on the performance and rate of error in manual activities. This was an interventional study conducted on 50 students at Shiraz University of Medical Sciences (25 males and 25 females) in which each person was considered as its own control to assess the effect of noise on her or his performance at the sound levels of 70, 90, and 110 dB by using two factors of physical features and the creation of different conditions of sound source as well as applying the Two-Arm coordination Test. The data were analyzed using SPSS version 16. Repeated measurements were used to compare the length of performance as well as the errors measured in the test. Based on the results, we found a direct and significant association between the levels of sound and the length of performance. Moreover, the participant's performance was significantly different for different sound levels (at 110 dB as opposed to 70 and 90 dB, p < 0.05 and p < 0.001, respectively). This study found that a sound level of 110 dB had an important effect on the individuals' performances, i.e., the performances were decreased.

  3. Equivalent threshold sound pressure levels (ETSPL) for Sennheiser HDA 280 supra-aural audiometric earphones in the frequency range 125 Hz to 8000 Hz.

    Science.gov (United States)

    Poulsen, Torben; Oakley, Sebastian

    2009-05-01

    Hearing threshold sound pressure levels were measured for the Sennheiser HDA 280 audiometric earphone. Hearing thresholds were measured for 25 normal-hearing test subjects at the 11 audiometric test frequencies from 125 Hz to 8000 Hz. Sennheiser HDA 280 is a supra-aural earphone that may be seen as a substitute for the classical Telephonics TDH 39. The results are given as the equivalent threshold sound pressure level (ETSPL) measured in an acoustic coupler specified in IEC 60318-3. The results are in good agreement with an independent investigation from PTB, Braunschweig, Germany. From acoustic laboratory measurements ETSPL values are calculated for the ear simulator specified in IEC 60318-1. Fitting of earphone and coupler is discussed. The data may be used for a future update of the RETSPL standard for supra-aural audiometric earphones, ISO 389-1.

  4. The impact of a noise reduction quality improvement project upon sound levels in the open-unit-design neonatal intensive care unit.

    Science.gov (United States)

    Liu, W F

    2010-07-01

    To decrease measured sound levels in the neonatal intensive care unit through implementation of human factor and minor design modification strategies. Prospective time series. Two open-unit-design neonatal centers. Implementation of a coordinated program of noise reduction strategies did not result in any measurable improvement in levels of loudness or quiet. Two centers, using primarily human behavior noise reduction strategies, were unable to demonstrate measurable improvements in sound levels within the occupied open-unit-design neonatal intensive care unit.

  5. Estimation of a noise level using coarse-grained entropy of experimental time series of internal pressure in a combustion engine

    International Nuclear Information System (INIS)

    Litak, Grzegorz; Taccani, Rodolfo; Radu, Robert; Urbanowicz, Krzysztof; HoIyst, Janusz A.; Wendeker, MirosIaw; Giadrossi, Alessandro

    2005-01-01

    We report our results on non-periodic experimental time series of pressure in a single cylinder spark ignition engine. The experiments were performed for different levels of loading. We estimate the noise level in internal pressure calculating the coarse-grained entropy from variations of maximal pressures in successive cycles. The results show that the dynamics of the combustion is a non-linear multidimensional process mediated by noise. Our results show that so defined level of noise in internal pressure is not monotonous function of loading

  6. Annoyance, detection and recognition of wind turbine noise.

    Science.gov (United States)

    Van Renterghem, Timothy; Bockstael, Annelies; De Weirt, Valentine; Botteldooren, Dick

    2013-07-01

    Annoyance, recognition and detection of noise from a single wind turbine were studied by means of a two-stage listening experiment with 50 participants with normal hearing abilities. In-situ recordings made at close distance from a 1.8-MW wind turbine operating at 22 rpm were mixed with road traffic noise, and processed to simulate indoor sound pressure levels at LAeq 40 dBA. In a first part, where people were unaware of the true purpose of the experiment, samples were played during a quiet leisure activity. Under these conditions, pure wind turbine noise gave very similar annoyance ratings as unmixed highway noise at the same equivalent level, while annoyance by local road traffic noise was significantly higher. In a second experiment, listeners were asked to identify the sample containing wind turbine noise in a paired comparison test. The detection limit of wind turbine noise in presence of highway noise was estimated to be as low as a signal-to-noise ratio of -23 dBA. When mixed with local road traffic, such a detection limit could not be determined. These findings support that noticing the sound could be an important aspect of wind turbine noise annoyance at the low equivalent levels typically observed indoors in practice. Participants that easily recognized wind-turbine(-like) sounds could detect wind turbine noise better when submersed in road traffic noise. Recognition of wind turbine sounds is also linked to higher annoyance. Awareness of the source is therefore a relevant aspect of wind turbine noise perception which is consistent with previous research. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Estimating raw material equivalents on a macro-level: comparison of multi-regional input-output analysis and hybrid LCI-IO.

    Science.gov (United States)

    Schoer, Karl; Wood, Richard; Arto, Iñaki; Weinzettel, Jan

    2013-12-17

    The mass of material consumed by a population has become a useful proxy for measuring environmental pressure. The "raw material equivalents" (RME) metric of material consumption addresses the issue of including the full supply chain (including imports) when calculating national or product level material impacts. The RME calculation suffers from data availability, however, as quantitative data on production practices along the full supply chain (in different regions) is required. Hence, the RME is currently being estimated by three main approaches: (1) assuming domestic technology in foreign economies, (2) utilizing region-specific life-cycle inventories (in a hybrid framework), and (3) utilizing multi-regional input-output (MRIO) analysis to explicitly cover all regions of the supply chain. While the first approach has been shown to give inaccurate results, this paper focuses on the benefits and costs of the latter two approaches. We analyze results from two key (MRIO and hybrid) projects modeling raw material equivalents, adjusting the models in a stepwise manner in order to quantify the effects of individual conceptual elements. We attempt to isolate the MRIO gap, which denotes the quantitative impact of calculating the RME of imports by an MRIO approach instead of the hybrid model, focusing on the RME of EU external trade imports. While, the models give quantitatively similar results, differences become more pronounced when tracking more detailed material flows. We assess the advantages and disadvantages of the two approaches and look forward to ways to further harmonize data and approaches.

  8. Do Cost Functions for Tracking Error Generalize across Tasks with Different Noise Levels?

    Directory of Open Access Journals (Sweden)

    Jonathon Sensinger

    Full Text Available Control of human-machine interfaces are well modeled by computational control models, which take into account the behavioral decisions people make in estimating task dynamics and state for a given control law. This control law is optimized according to a cost function, which for the sake of mathematical tractability is typically represented as a series of quadratic terms. Recent studies have found that people actually use cost functions for reaching tasks that are slightly different than a quadratic function, but it is unclear which of several cost functions best explain human behavior and if these cost functions generalize across tasks of similar nature but different scale. In this study, we used an inverse-decision-theory technique to reconstruct the cost function from empirical data collected on 24 able-bodied subjects controlling a myoelectric interface. Compared with previous studies, this experimental paradigm involved a different control source (myoelectric control, which has inherently large multiplicative noise, a different control interface (control signal was mapped to cursor velocity, and a different task (the tracking position dynamically moved on the screen throughout each trial. Several cost functions, including a linear-quadratic; an inverted Gaussian, and a power function, accurately described the behavior of subjects throughout this experiment better than a quadratic cost function or other explored candidate cost functions (p<0.05. Importantly, despite the differences in the experimental paradigm and a substantially larger scale of error, we found only one candidate cost function whose parameter was consistent with the previous studies: a power function (cost ∝ errorα with a parameter value of α = 1.69 (1.53-1.78 interquartile range. This result suggests that a power-function is a representative function of user's error cost over a range of noise amplitudes for pointing and tracking tasks.

  9. Approaches to decrease the level of parasitic noise over vibroacoustic channel in terms of configuring information security tools

    Science.gov (United States)

    Ivanov, A. V.; Reva, I. L.; Babin, A. A.

    2018-04-01

    The article deals with influence of various ways to place vibration transmitters on efficiency of rooms safety for negotiations. Standing for remote vibration listening of window glass, electro-optical channel, the most typical technical channel of information leakage, was investigated. The modern system “Sonata-AB” of 4B model is used as an active protection tool. Factors influencing on security tools configuration efficiency have been determined. The results allow utilizer to reduce masking interference level as well as parasitic noise with keeping properties of room safety.

  10. Variations in voice level and fundamental frequency with changing background noise level and talker-to-listener distance while wearing hearing protectors: A pilot study.

    Science.gov (United States)

    Bouserhal, Rachel E; Macdonald, Ewen N; Falk, Tiago H; Voix, Jérémie

    2016-01-01

    Speech production in noise with varying talker-to-listener distance has been well studied for the open ear condition. However, occluding the ear canal can affect the auditory feedback and cause deviations from the models presented for the open-ear condition. Communication is a main concern for people wearing hearing protection devices (HPD). Although practical, radio communication is cumbersome, as it does not distinguish designated receivers. A smarter radio communication protocol must be developed to alleviate this problem. Thus, it is necessary to model speech production in noise while wearing HPDs. Such a model opens the door to radio communication systems that distinguish receivers and offer more efficient communication between persons wearing HPDs. This paper presents the results of a pilot study aimed to investigate the effects of occluding the ear on changes in voice level and fundamental frequency in noise and with varying talker-to-listener distance. Twelve participants with a mean age of 28 participated in this study. Compared to existing data, results show a trend similar to the open ear condition with the exception of the occluded quiet condition. This implies that a model can be developed to better understand speech production for the occluded ear.

  11. Detecting Levels of Polyquaternium-10 (PQ-10) via Potentiometric Titration with Dextran Sulphate and Monitoring the Equivalence Point with a Polymeric Membrane-Based Polyion Sensor.

    Science.gov (United States)

    Ferguson, Stephen A; Wang, Xuewei; Meyerhoff, Mark E

    2016-08-07

    Polymeric quaternary ammonium salts (polyquaterniums) have found increasing use in industrial and cosmetic applications in recent years. More specifically, polyquaternium-10 (PQ-10) is routinely used in cosmetic applications as a conditioner in personal care product formulations. Herein, we demonstrate the use of potentiometric polyion-sensitive polymeric membrane-based electrodes to quantify PQ-10 levels. Mixtures containing both PQ-10 and sodium lauryl sulfate (SLS) are used as model samples to illustrate this new method. SLS is often present in cosmetic samples that contain PQ-10 (e.g., shampoos, etc.) and this surfactant species interferes with the polyion sensor detection chemistry. However, it is shown here that SLS can be readily separated from the PQ-10/SLS mixture by use of an anion-exchange resin and that the PQ-10 can then be titrated with dextran sulphate (DS). This titration is monitored by potentiometric polyanion sensors to provide equivalence points that are directly proportional to PQ-10 concentrations.

  12. Comparison of classical statistical methods and artificial neural network in traffic noise prediction

    International Nuclear Information System (INIS)

    Nedic, Vladimir; Despotovic, Danijela; Cvetanovic, Slobodan; Despotovic, Milan; Babic, Sasa

    2014-01-01

    Traffic is the main source of noise in urban environments and significantly affects human mental and physical health and labor productivity. Therefore it is very important to model the noise produced by various vehicles. Techniques for traffic noise prediction are mainly based on regression analysis, which generally is not good enough to describe the trends of noise. In this paper the application of artificial neural networks (ANNs) for the prediction of traffic noise is presented. As input variables of the neural network, the proposed structure of the traffic flow and the average speed of the traffic flow are chosen. The output variable of the network is the equivalent noise level in the given time period L eq . Based on these parameters, the network is modeled, trained and tested through a comparative analysis of the calculated values and measured levels of traffic noise using the originally developed user friendly software package. It is shown that the artificial neural networks can be a useful tool for the prediction of noise with sufficient accuracy. In addition, the measured values were also used to calculate equivalent noise level by means of classical methods, and comparative analysis is given. The results clearly show that ANN approach is superior in traffic noise level prediction to any other statistical method. - Highlights: • We proposed an ANN model for prediction of traffic noise. • We developed originally designed user friendly software package. • The results are compared with classical statistical methods. • The results are much better predictive capabilities of ANN model

  13. Comparison of classical statistical methods and artificial neural network in traffic noise prediction

    Energy Technology Data Exchange (ETDEWEB)

    Nedic, Vladimir, E-mail: vnedic@kg.ac.rs [Faculty of Philology and Arts, University of Kragujevac, Jovana Cvijića bb, 34000 Kragujevac (Serbia); Despotovic, Danijela, E-mail: ddespotovic@kg.ac.rs [Faculty of Economics, University of Kragujevac, Djure Pucara Starog 3, 34000 Kragujevac (Serbia); Cvetanovic, Slobodan, E-mail: slobodan.cvetanovic@eknfak.ni.ac.rs [Faculty of Economics, University of Niš, Trg kralja Aleksandra Ujedinitelja, 18000 Niš (Serbia); Despotovic, Milan, E-mail: mdespotovic@kg.ac.rs [Faculty of Engineering, University of Kragujevac, Sestre Janjic 6, 34000 Kragujevac (Serbia); Babic, Sasa, E-mail: babicsf@yahoo.com [College of Applied Mechanical Engineering, Trstenik (Serbia)

    2014-11-15

    Traffic is the main source of noise in urban environments and significantly affects human mental and physical health and labor productivity. Therefore it is very important to model the noise produced by various vehicles. Techniques for traffic noise prediction are mainly based on regression analysis, which generally is not good enough to describe the trends of noise. In this paper the application of artificial neural networks (ANNs) for the prediction of traffic noise is presented. As input variables of the neural network, the proposed structure of the traffic flow and the average speed of the traffic flow are chosen. The output variable of the network is the equivalent noise level in the given time period L{sub eq}. Based on these parameters, the network is modeled, trained and tested through a comparative analysis of the calculated values and measured levels of traffic noise using the originally developed user friendly software package. It is shown that the artificial neural networks can be a useful tool for the prediction of noise with sufficient accuracy. In addition, the measured values were also used to calculate equivalent noise level by means of classical methods, and comparative analysis is given. The results clearly show that ANN approach is superior in traffic noise level prediction to any other statistical method. - Highlights: • We proposed an ANN model for prediction of traffic noise. • We developed originally designed user friendly software package. • The results are compared with classical statistical methods. • The results are much better predictive capabilities of ANN model.

  14. Effects of acoustic treatment on the interior noise levels of a twin-engine propeller aircraft - Experimental flight results and theoretical predictions

    Science.gov (United States)

    Beyer, T. B.; Powell, C. A.; Daniels, E. F.; Pope, L. D.

    1984-01-01

    In-flight noise level measurements were made within two cabin configurations of a general aviation business aircraft. The Fairchild Merlin IVC twin-engine aircraft was tested with bare walls and fiberglass insulation and in an executive trim configuration. Narrow-band and octave format data were subjected to analyses which permitted identification of the blade passage harmonics (BPH). Cabin noise level reductions (insertion losses) due to added insulation varied with position in the cabin, the BPH number, cabin pressure, and engine torque. The measurements were closely predicted using the propeller aircraft interior noise (PAIN) mode.

  15. The Influence of Geography and Geology on Seismic Background Noise Levels Across the United States as Revealed by the Transportable Array

    Science.gov (United States)

    Anthony, R. E.; Ringler, A. T.; Holland, A. A.; Wilson, D. C.

    2017-12-01

    The EarthScope USArray Transportable Array (TA) has now covered the US with 3-component broadband seismometers at approximately 70 km station spacing and deployment durations of approximately 2 years. This unprecedented coverage, combined with high-quality and near homogenous installation techniques, offers a novel dataset in which to characterize spatially varying levels of background seismic noise across the United States. We present background noise maps in period bands of interest to earthquake and imaging seismology across the US (lower 48 states and Alaska). Early results from the contiguous 48 states demonstrate that ambient noise levels within the body wave period band (1-5 s) vary by > 20 dB (rel. 1 (m/s2)2/Hz) with the highest noise levels occurring at stations located within sedimentary basins and lowest within the mountain ranges of the Western US. Additionally, stations around the Great Lakes observe heightened noise levels in this band beyond the aforementioned basin amplification. We attribute this observation to local swell activity in the Great Lakes generating short-period microseism signals. This suggests that lake-generated microseisms may be a significant source of noise for Alaskan deployments situated in close proximity to lakes to facilitate float plane access. We further investigate how basin amplification and short-period lake microseism signals may noticeably impact detection and signal-to-noise of teleseismic body wave signals during certain time periods. At longer-periods (> 20 s), we generally observe larger noise levels on the horizontal components of stations situated in basins or on soft sediment, likely caused by locally induced tilt of the sensor. We will present similar analysis from the initial Alaska TA dataset to quantitatively assess how utilization of posthole sensors affects signal-to-noise for the long-period horizontal wavefield.

  16. A new IEA document for the measurement of noise immission from wind turbines at receptor locations

    International Nuclear Information System (INIS)

    Ljunggren, Sten

    1999-01-01

    A new IEA guide on acoustic noise was recently completed by an international expert group. In this guide, several practical and reliable methods for determining wind turbine noise immission at receptor locations are presented: three methods for equivalent continuous A-weighted sound pressure levels and one method for A-weighted percentiles. In the most ambitious method for equivalent sound levels, the noise is measured together with the wind speed at two locations: one at the microphone and the other at the turbine site. With this approach, the turbine levels can be corrected for background sound and the immission level can be determined at a certain target speed. Special importance is attached to the problem of correcting for background noise and to techniques for improving the signal-to-noise ratio. Thus, six methods are described which can be used in difficult situations

  17. Common mode noise in three-level DC-DC converters

    CSIR Research Space (South Africa)

    Grobler, Inus

    2009-09-01

    Full Text Available that three-level buck DC-DC converters in general generate much lower common mode currents than conventional two-level buck converters. Further, reductions in common mode currents are achieved by using the improved three-level topologies that have been...

  18. Electronic noise in CT detectors: Impact on image noise and artifacts.

    Science.gov (United States)

    Duan, Xinhui; Wang, Jia; Leng, Shuai; Schmidt, Bernhard; Allmendinger, Thomas; Grant, Katharine; Flohr, Thomas; McCollough, Cynthia H

    2013-10-01

    The objective of our study was to evaluate in phantoms the differences in CT image noise and artifact level between two types of commercial CT detectors: one with distributed electronics (conventional) and one with integrated electronics intended to decrease system electronic noise. Cylindric water phantoms of 20, 30, and 40 cm in diameter were scanned using two CT scanners, one equipped with integrated detector electronics and one with distributed detector electronics. All other scanning parameters were identical. Scans were acquired at four tube potentials and 10 tube currents. Semianthropomorphic phantoms were scanned to mimic the shoulder and abdominal regions. Images of two patients were also selected to show the clinical values of the integrated detector. Reduction of image noise with the integrated detector depended on phantom size, tube potential, and tube current. Scans that had low detected signal had the greatest reductions in noise, up to 40% for a 30-cm phantom scanned using 80 kV. This noise reduction translated into up to 50% in dose reduction to achieve equivalent image noise. Streak artifacts through regions of high attenuation were reduced by up to 45% on scans obtained using the integrated detector. Patient images also showed superior image quality for the integrated detector. For the same applied radiation level, the use of integrated electronics in a CT detector showed a substantially reduced level of electronic noise, resulting in reductions in image noise and artifacts, compared with detectors having distributed electronics.

  19. Hearing Threshold, Loss, Noise Levels and Worker's Profiles of an Open Cast Chromite Mines in Odisha, India.

    Science.gov (United States)

    Kerketta, Sunamani; Gartia, Rajendra; Bagh, Somanath

    2012-10-01

    The aims of the study were to describe the noise levels at an open cast chromite mine in Odisha, India, and the hearing threshold of its workers and to associate their hearing loss with their age, work station and length of employment at the mine. We performed a cross-sectional study of the hearing threshold of chromite mine workers. Audiometric data from 500 subjects was collected at the mines' hospital in the Sukinda Valley of Jajpur, Odisha, India. The latest audiometry data available for the period 2002 to 2008 was used in the analysis. Audiometric screening was performed using an audiometer (TRIVENI TAM-25 6025A) in a quiet environment by qualified technicians, audiologists or physicians. Tests were conducted on the subjects after they had completely rested for 16 hours or more after their day shift. A maximum of 262 subjects (52.4%) were employed in the work zone area and a minimum of 2 subjects (0.4%) had less than 5 years working experience. The age of the subjects ranged from 29 to 59 years and their working experience ranged from 4 to 37 years. The subjects' average mean hearing thresholds at 4, 6 and 8 kHz were 21.53 dBA, 23.40 dBA and 21.90 dBA, respectively. The maximum Leq and L90 levels exceeded the prescribed limits for commercial, residential and silence zones. The maximum Leq levels exceeded 95 dBA for large and medium heavy earth moving machineries (HEMMs), both outside and at the operator's position. Hearing loss due to the subjects' work experience was found to be greater than that attributable to age and workstation. In our study population, the maximum noise levels for large and medium HEMMs and inside the cabins of HEMMs were found to be more than 95 dBA. This indicates that operators in this particular chromite mine at Odisha, India were exposed to noise levels exceeding 95 dBA for more than 10% of the monitoring time. The subjects' hearing loss was also found to increase for every 10-year age interval and that for every 5 years of work

  20. Noise and vibration levels in artificial polar bear dens as related to selected petroleum exploration and developmental activities

    International Nuclear Information System (INIS)

    Blix, A.S.; Lentfer, J.W.

    1992-01-01

    Petroleum exploration and development are occurring in various locations in the Arctic, where there are important denning sites for polar bears. Petroleum activities usually coincide with winter denning activities by bears, who may abandon dens if subject to prolonged annoyance. A study was carried out to measure noise and vibration levels in artificial polar bear dens at Prudhoe's Bar, Alaska, resulting from seismic testing, drilling and transport. A microphone and an accelerometer were frozen to the floor of the dens, with leads passed through a consolidated snow filled entrance to a truck, tent or helicopter. Tests were carried out on land, sea ice, and next to a drilling tower on an artificial island, which was also used to measure noise levels resulting from a helicopter taking off. It was concluded that the dry and wind-beaten arctic snow muffles both sound and vibration extremely well, and it is unlikely that polar bears in their dens will be disturbed by the type of petroleum-related activities measured, provided they do not take place within 100 m of the dens. 8 refs., 7 figs., 1 tab

  1. Noise genetics: inferring protein function by correlating phenotype with protein levels and localization in individual human cells.

    Directory of Open Access Journals (Sweden)

    Shlomit Farkash-Amar

    2014-03-01

    Full Text Available To understand gene function, genetic analysis uses large perturbations such as gene deletion, knockdown or over-expression. Large perturbations have drawbacks: they move the cell far from its normal working point, and can thus be masked by off-target effects or compensation by other genes. Here, we offer a complementary approach, called noise genetics. We use natural cell-cell variations in protein level and localization, and correlate them to the natural variations of the phenotype of the same cells. Observing these variations is made possible by recent advances in dynamic proteomics that allow measuring proteins over time in individual living cells. Using motility of human cancer cells as a model system, and time-lapse microscopy on 566 fluorescently tagged proteins, we found 74 candidate motility genes whose level or localization strongly correlate with motility in individual cells. We recovered 30 known motility genes, and validated several novel ones by mild knockdown experiments. Noise genetics can complement standard genetics for a variety of phenotypes.

  2. Low-level human equivalent gestational lead exposure produces sex-specific motor and coordination abnormalities and late-onset obesity in year-old mice.

    Science.gov (United States)

    Leasure, J Leigh; Giddabasappa, Anand; Chaney, Shawntay; Johnson, Jerry E; Pothakos, Konstantinos; Lau, Yuen Sum; Fox, Donald A

    2008-03-01

    Low-level developmental lead exposure is linked to cognitive and neurological disorders in children. However, the long-term effects of gestational lead exposure (GLE) have received little attention. Our goals were to establish a murine model of human equivalent GLE and to determine dose-response effects on body weight, motor functions, and dopamine neurochemistry in year-old offspring. We exposed female C57BL/6 mice to water containing 0, 27 (low), 55 (moderate), or 109 ppm (high) of lead from 2 weeks prior to mating, throughout gestation, and until postnatal day 10 (PN10). Maternal and litter measures, blood lead concentrations ([BPb]), and body weights were obtained throughout the experiment. Locomotor behavior in the absence and presence of amphetamine, running wheel activity, rotarod test, and dopamine utilization were examined in year-old mice. Peak [BPb] were obesity. Similarly, we observed male-specific decreased spontaneous motor activity, increased amphetamine-induced motor activity, and decreased rotarod performance in year-old GLE mice. Levels of dopamine and its major metabolite were altered in year-old male mice, although only forebrain utilization increased. GLE-induced alterations were consistently larger in low-dose GLE mice. Our novel results show that GLE produced permanent male-specific deficits. The nonmonotonic dose-dependent responses showed that low-level GLE produced the most adverse effects. These data reinforce the idea that lifetime measures of dose-response toxicant exposure should be a component of the neurotoxic risk assessment process.

  3. Honey and Vitamin E Restore the Plasma Level of Gonadal Hormones and Improve the Fertilization Capacity in Noise-Stressed Rats

    Directory of Open Access Journals (Sweden)

    Rajabzadeh Asghar

    2015-04-01

    Full Text Available Objective: Noise as a natural teratogenic factor affects the body systems including the reproductive organ to reduce the fertility rate and fetus health. Honey and vitamin E as natural antioxidants protects the sperm released from the reproductive system. This study was conducted to examine the efficacy of honey and vitamin E on fertilization capacity in noise-exposed rats by assessing plasma sexual hormones levels i.e., follicle-stimulating hormone (FSH, luteinizing hormone (LH, and testosterone, altered in relation with noise stress. Materials and Methods: This study was targeted the 24 male rats that randomly were divided into four equal groups including one control group (unexposed to noise stress and three experimental groups pre-induced with noise stress for 50 days and then divided as: no treated, honey and vitamin E treated groups, respectively. Then, the blood samples of experimental and control groups were taken, and the serum level of the sexual hormones was analyzed. Finally, to investigate the fertility capacity of rats, the male rats of all groups were coupled with the female ones. Results: Our results showed that FSH and LH level in noise stressed male rats raised, and the testosterone secretion decreased compared to the control group. Moreover, noise stress injury could reduce weight and the survival rate of the fetus. However, the honey and vitamin E improved the testosterone concentration, declined the plasma FSH and LH level in noise - exposed rats and enhanced the fertility rate. Conclusion: These findings may also spell out a natural curative approach rather than pharmaceutical drugs to optimize of neuroendocrine gonadal axis and testicular integrity induced by pathogenesis stress, i.e., noise and enhance the male fertility capacity.

  4. Pathogenesis mechanism by noise induced clinical pictures-lessons from the Spandau health-survey; Pathogenesemechanismen bei laerminduzierten Krankheitsbildern - Schlussfolgerungen aus dem Spandauer Gesundheits-Survey

    Energy Technology Data Exchange (ETDEWEB)

    Maschke, C. [Forschungs- und Beratungsbuero Maschke (FBB-Maschke), Berlin (Germany); Hecht, K. [Interdisziplinaerer Forschungsverbund Laerm und Gesundheit, Berlin (Germany)

    2005-07-01

    Traffic noise (road noise, flight noise, train noise) is the predominant noise source in the living environment, followed by neighbourhood noise. Through the central nervous processes noise can lead, via disturbed sleep as well as via subjective experience, to an inadequate neuro-endocrine reaction with the possibility of finally leading to diseases which are mediated or triggered by stress. Noise induced health disturbances by traffic noise is a large and contrarily discussed problem. In the context of the Spandau health survey, both the noise load (equivalent sound level) and the noise experience (disturbances) were collected and the relationship with medically treated illnesses evaluated. The results suggest that two different ''effect mechanisms'' exist regarding the health effect of traffic noise. Besides the noise disturbed sleep, an insufficient coping with the noise exposures can lead to increased disease risks. The study shows convincing relations between impairments of the heart circulation system (e.g. with hypertension) and the nightly equivalent sound level (22.00-6:00 hours) at the place of residents of the test persons. It has to be assumed that this is the long-term result of sleep which is not restful. On the other hand, psychic disturbances were less connected to the sound level and had more correlation with the noise experience. With psychic disturbances the individual overtaxing of the information-processing processes plays an important role and is classified as an emotional stress situation. (orig.)

  5. Noise behaviour of semiinsulating GaAs particle detectors at various temperatures before and after irradiation

    International Nuclear Information System (INIS)

    Tenbusch, F.; Braunschweig, W.; Chu, Z.; Krais, R.; Kubicki, T.; Luebelsmeyer, K.; Pandoulas, D.; Rente, C.; Syben, O.; Toporowski, M.; Wittmer, B.; Xiao, W.J.

    1998-01-01

    We investigated the noise behaviour of surface barrier detectors (double sided Schottky contact) made of semiinsulating GaAs. Two types of measurements were performed: equivalent noise charge (ENC) and noise power density spectra in a frequency range from 10 Hz to 500 kHz. The shape of the density spectra are a powerful tool to examine the physical origin of the noise, before irradiation it is dominated by generation-recombination processes caused by deep levels. Temperature dependent noise measurements reveal the deep level parameters like activation energy and cross section, which are also extracted by analyzing the time transients of the charge pulse from α-particles. After irradiation with protons, neutrons and pions the influence of the deep levels being originally responsible for the noise is found to decrease and a reduction of the noise over the entire frequency range with increasing fluence is observed. (orig.)

  6. Electrochemically reduced water exerts superior reactive oxygen species scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water.

    Directory of Open Access Journals (Sweden)

    Takeki Hamasaki

    Full Text Available Electrochemically reduced water (ERW is produced near a cathode during electrolysis and exhibits an alkaline pH, contains richly dissolved hydrogen, and contains a small amount of platinum nanoparticles. ERW has reactive oxygen species (ROS-scavenging activity and recent studies demonstrated that hydrogen-dissolved water exhibits ROS-scavenging activity. Thus, the antioxidative capacity of ERW is postulated to be dependent on the presence of hydrogen levels; however, there is no report verifying the role of dissolved hydrogen in ERW. In this report, we clarify whether the responsive factor for antioxidative activity in ERW is dissolved hydrogen. The intracellular ROS scavenging activity of ERW and hydrogen-dissolved water was tested by both fluorescent stain method and immuno spin trapping assay. We confirm that ERW possessed electrolysis intensity-dependent intracellular ROS-scavenging activity, and ERW exerts significantly superior ROS-scavenging activity in HT1080 cells than the equivalent level of hydrogen-dissolved water. ERW retained its ROS-scavenging activity after removal of dissolved hydrogen, but lost its activity when autoclaved. An oxygen radical absorbance capacity assay, the 2,2-diphenyl-1-picrylhydrazyl assay and chemiluminescence assay could not detect radical-scavenging activity in both ERW and hydrogen-dissolved water. These results indicate that ERW contains electrolysis-dependent hydrogen and an additional antioxidative factor predicted to be platinum nanoparticles.

  7. Influence of military low-level flight noise on the inner ear of guinea pigs. Der Einfluss von militaerischem Tieffluglaerm auf das Innenohr des Meerschweinchens

    Energy Technology Data Exchange (ETDEWEB)

    Gehrig, W.; Meyer, P.; Kuhl, K.D.; Schmidt, R.; Gruetzmacher, W. (Greifswald Univ. (Germany). HNO-Klinik); Ising, H. (BGA, Berlin (Germany). Inst. fuer Wasser-, Boden- und Lufthygiene); Ishi, K.; Merker, H.J. (Freie Univ. Berlin (Germany). Inst. fuer Anatomie)

    1992-03-01

    The influence of different rises in noise level and - in cases of the repeated passage of aircraft - the impact of varying intervals between the events was to be investigated. The experimental animals used were pigmented guinea pigs of 250 to 500 grammes body weight. The auditory thresholds were measured on the anaesthesized animals by derivation of the acoustically evoked brain stem potentials from the EEGs. For the noise exposure of the animals, two types of military low-level flight noise were used: one flight overhead with a rise in noise level of 7.5 dB/s, and a second one with 75 dB/s.-unlike other cases of damage to the inner ear through noise, the damage sustained in this case was not restricted to the basal convolution but was observed in all four cochlear convolutions. This suggests a particularity of the harmful effect of low-level flight noise, which it is planned to follow up in the future. (orig./MG).

  8. Drone noise

    Science.gov (United States)

    Tinney, Charles; Sirohi, Jayant; University of Texas at Austin Team

    2017-11-01

    A basic understanding of the noise produced by single and multirotor drones operating at static thrust conditions is presented. This work acts as an extension to previous efforts conducted at The University of Texas at Austin (Tinney et al. 2017, AHS Forum 73). Propeller diameters ranging from 8 inch to 12 inch are examined for configurations comprising an isolated rotor, a quadcopter configuration and a hexacopter configuration, and with a constant drone pitch of 2.25. An azimuthal array of half-inch microphones, placed between 2 and 3 hub-center diameters from the drone center, are used to assess the acoustic near-field. Thrust levels, acquired using a six degree-of-freedom load cell, are then used to correlate acoustic noise levels to aerodynamic performance for each drone configuration. The findings reveal a nearly logarithmic increase in noise with increasing thrust. However, for the same thrust condition, considerable noise reduction is achieved by increasing the number of propeller blades thereby reducing the blade passage frequency and both the thickness and loading noise sources that accompany it.

  9. Measuring changes in ambient noise levels from the installation and operation of a surge wave energy converter in the coastal ocean

    Energy Technology Data Exchange (ETDEWEB)

    Haxel, Joe H [Oregon State Univ., Newport, OR (United States); Henkel, Sarah K [Oregon State Univ., Newport, OR (United States)

    2017-10-18

    Ecosystem impacts resulting from elevated underwater noise levels generated by anthropogenic activities in the coastal ocean are poorly understood and remain difficult to address as a result of a significant gap in knowledge for existing nearshore sound levels. Ambient noise is an important habitat component for marine mammals and fish that use sound for essential functions such as communication, navigation, and foraging. Questions surrounding the amplitudes, frequency distributions, and durations of noise emissions from renewable wave energy conversion (WEC) projects during their construction and operation present concerns for long-term consequences in marine habitats. Oregon’s dynamic nearshore environment presents significant challenges for passive acoustic monitoring that include flow noise contamination from wave orbital motions, turbulence from breaking surf, equipment burial, and fishing pressure from sport and commercial crabbers. This project included 2 techniques for passive acoustic data collection: 1) campaign style deployments of fixed hydrophone lander stations to capture temporal variations in noise levels and 2) a drifting hydrophone system to record spatial variations within the project site. The hydrophone lander deployments were effective and economically feasible for enabling robust temporal measurements of ambient noise levels in a variety of sea state conditions. Limiting factors for the fixed stations included 1) a flow shield mitigation strategy failure in the first deployment resulting in significant wideband data contamination and 2) flow noise contamination of the unshielded sensors restricting valuable analysis to frequencies above 500 Hz for subsequent deployments. Drifting hydrophone measurements were also effective and economically feasible (although logistically challenging in the beginning of the project due to vessel time constraints) providing a spatial distribution of sound levels, comparisons of noise levels in varying levels

  10. Background Noise Analysis in a Few-Photon-Level Qubit Memory

    Science.gov (United States)

    Mittiga, Thomas; Kupchak, Connor; Jordaan, Bertus; Namazi, Mehdi; Nolleke, Christian; Figeroa, Eden

    2014-05-01

    We have developed an Electromagnetically Induced Transparency based polarization qubit memory. The device is composed of a dual-rail probe field polarization setup colinear with an intense control field to store and retrieve any arbitrary polarization state by addressing a Λ-type energy level scheme in a 87Rb vapor cell. To achieve a signal-to-background ratio at the few photon level sufficient for polarization tomography of the retrieved state, the intense control field is filtered out through an etalon filtrating system. We have developed an analytical model predicting the influence of the signal-to-background ratio on the fidelities and compared it to experimental data. Experimentally measured global fidelities have been found to follow closely the theoretical prediction as signal-to-background decreases. These results suggest the plausibility of employing room temperature memories to store photonic qubits at the single photon level and for future applications in long distance quantum communication schemes.

  11. Politico-economic equivalence

    DEFF Research Database (Denmark)

    Gonzalez Eiras, Martin; Niepelt, Dirk

    2015-01-01

    Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime and a st......Traditional "economic equivalence'' results, like the Ricardian equivalence proposition, define equivalence classes over exogenous policies. We derive "politico-economic equivalence" conditions that apply in environments where policy is endogenous and chosen sequentially. A policy regime...... their use in the context of several applications, relating to social security reform, tax-smoothing policies and measures to correct externalities....

  12. Railway noise annoyance on the railway track in northwest slovakia.

    Science.gov (United States)

    Pultznerova, Alzbeta; Eva, Panulinova; Kucharova, Daniela; Argalasova, Lubica

    2018-01-01

    This paper describes an assessment of noise caused by railway traffic in a large high-loaded railway track in Northwest Slovakia. The measurements of noise levels generated by trains passing through residential neighborhoods were taken. Noise maps were also calculated showing noise pollution generated by the train traffic. In addition, the annoyance level and sleep disturbance of residents affected by railway noise were evaluated by a validated questionnaire on a pilot sample of 107 respondents living near the important railway track. The measurements indicated that the noise levels generated by the passage of the train were extremely high especially at night, clearly exceeding the nighttime limits of equivalent sound pressure level established by the Decree of the Slovak Ministry of Health (No.549/2007) (L Aeq  = 55 dB). Measurements at one point during the night exceeded the limit values of up to 17.4 dB. The residents reported feeling affected by the noise generated by passing trains, which caused irritability, headache, poor concentration, and insomnia. In addition, 19.64% of the residents claimed that nocturnal noise pollution was the most distressing. The results of bivariate analysis showed a higher risk of annoyance especially for railway noise [OR MH  = 7.80 (4.02-15.14)] and the noise from industry [OR MH  = 3.08 (1.72-5.50)] in the exposed location. The effects of railway traffic on annoyance/sleep and psychosocial well-being were evaluated in a few studies. In accordance with our results the railway noise mostly disturbs sleep and rest of the respondents. The pilot survey showed the importance of sleep and rest disturbance by railway noise and the possibilities of getting worse health condition in the future. Noise abatement measures and strategies should, therefore, be implemented in an effective and manageable way increasing the environmental advantages of rail transport.

  13. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    Energy Technology Data Exchange (ETDEWEB)

    Widmann, Gerlig; Schullian, Peter [Medical University of Innsbruck, Department of Radiology, Innsbruck (Austria); Al-Shawaf, Reema; Al-Sadhan, Ra' ed; Al-Ekrish, Asma' a A. [King Saud University, Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, Riyadh (Saudi Arabia); Hoermann, Romed [Medical University of Innsbruck, Division of Clinical and Functional Anatomy, Innsbruck (Austria)

    2017-05-15

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  14. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites

    International Nuclear Information System (INIS)

    Widmann, Gerlig; Schullian, Peter; Al-Shawaf, Reema; Al-Sadhan, Ra'ed; Al-Ekrish, Asma'a A.; Hoermann, Romed

    2017-01-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. (orig.)

  15. Cancer risk assessment of polycyclic aromatic hydrocarbon contaminated soils determined using bioassay-derived levels of benzo[a]pyrene equivalents.

    Science.gov (United States)

    Lemieux, Christine L; Long, Alexandra S; Lambert, Iain B; Lundstedt, Staffan; Tysklind, Mats; White, Paul A

    2015-02-03

    Here we evaluate the excess lifetime cancer risk (ELCR) posed by 10 PAH-contaminated soils using (i) the currently advocated, targeted chemical-specific approach that assumes dose additivity for carcinogenic PAHs and (ii) a bioassay-based approach that employs the in vitro mutagenic activity of the soil fractions to determine levels of benzo[a]pyrene equivalents and, by extension, ELCR. Mutagenic activity results are presented in our companion paper.1 The results show that ELCR values for the PAH-containing fractions, determined using the chemical-specific approach, are generally (i.e., 8 out of 10) greater than those calculated using the bioassay-based approach; most are less than 5-fold greater. Only two chemical-specific ELCR estimates are less than their corresponding bioassay-derived values; differences are less than 10%. The bioassay-based approach, which permits estimation of ELCR without a priori knowledge of mixture composition, proved to be a useful tool to evaluate the chemical-specific approach. The results suggest that ELCR estimates for complex PAH mixtures determined using a targeted, chemical-specific approach are reasonable, albeit conservative. Calculated risk estimates still depend on contentious PEFs and cancer slope factors. Follow-up in vivo mutagenicity assessments will be required to validate the results and their relevance for human health risk assessment of PAH-contaminated soils.

  16. Noise and Hearing Loss Prevention

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . NOISE AND HEARING LOSS PREVENTION Language: English (US) Español ( ... when hazardous noise levels cannot be adequately reduced. Noise and Hearing Loss on the NIOSH Science Blog ...

  17. A study on the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise

    Directory of Open Access Journals (Sweden)

    Yukio Takahashi

    2011-01-01

    Full Text Available To investigate the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise, we conducted two experiments. In Experiment 1, eight male subjects were exposed to seven types of low-frequency noise stimuli: two pure tones [a 31.5-Hz, 100-dB(SPL tone and a 50-Hz, 100-dB(SPL tone] and five complex noises composed of the pure tones. For the complex noise stimuli, the sound pressure level of one tonal component was 100 dB(SPL and that of another one was either 90, 95, or 100 dB(SPL. Vibration induced on the body surface was measured at five locations, and the correlation with the subjective rating of the vibratory sensation at each site of measurement was examined. In Experiment 2, the correlation between the body surface vibration and the vibratory sensation was similarly examined using seven types of noise stimuli composed of a 25-Hz tone and a 50-Hz tone. In both the experiments, we found that at the chest and the abdomen, the rating of the vibratory sensation was in close correlation with the vibration acceleration level (VAL of the body surface vibration measured at each corresponding location. This was consistent with our previous results and suggested that at the trunk of the body (the chest and the abdomen, the mechanoreception of body vibrations plays an important role in the experience of the vibratory sensation in persons exposed to high-level low-frequency noise. At the head, however, no close correlation was found between the rating of the vibratory sensation and the VAL of body surface vibration. This suggested that at the head, the perceptual mechanisms of vibration induced by high-level low-frequency noise were different from those in the trunk of the body.

  18. Noise annoyance through railway traffic - a case study.

    Science.gov (United States)

    Trombetta Zannin, Paulo Henrique; Bunn, Fernando

    2014-01-08

    This paper describes an assessment of noise caused by railway traffic in a large Latin American city. Measurements were taken of noise levels generated by trains passing through residential neighborhoods with and without blowing their horns. Noise maps were also calculated showing noise pollution generated by the train traffic. In addition - annoyance of the residents - affected by railway noise, was evaluated based on interviews. The measurements indicated that the noise levels generated by the passage of the train with its horn blowing are extremely high, clearly exceeding the daytime limits of equivalent sound pressure level - Leq = 55 dB(A) - established by the municipal laws No 10.625 of the city of Curitiba. The Leq = 45 dB (A) which is the limit for the night period also are exceeded during the passage of trains. The residents reported feeling affected by the noise generated by passing trains, which causes irritability, headaches, poor concentration and insomnia, and 88% of them claimed that nocturnal noise pollution is the most distressing. This study showed that the vast majority of residents surveyed, (69%) believe that the noise of the train can devalue their property.

  19. Effect of ultra-low doses, ASIR and MBIR on density and noise levels of MDCT images of dental implant sites.

    Science.gov (United States)

    Widmann, Gerlig; Al-Shawaf, Reema; Schullian, Peter; Al-Sadhan, Ra'ed; Hörmann, Romed; Al-Ekrish, Asma'a A

    2017-05-01

    Differences in noise and density values in MDCT images obtained using ultra-low doses with FBP, ASIR, and MBIR may possibly affect implant site density analysis. The aim of this study was to compare density and noise measurements recorded from dental implant sites using ultra-low doses combined with FBP, ASIR, and MBIR. Cadavers were scanned using a standard protocol and four low-dose protocols. Scans were reconstructed using FBP, ASIR-50, ASIR-100, and MBIR, and either a bone or standard reconstruction kernel. Density (mean Hounsfield units [HUs]) of alveolar bone and noise levels (mean standard deviation of HUs) was recorded from all datasets and measurements were compared by paired t tests and two-way ANOVA with repeated measures. Significant differences in density and noise were found between the reference dose/FBP protocol and almost all test combinations. Maximum mean differences in HU were 178.35 (bone kernel) and 273.74 (standard kernel), and in noise, were 243.73 (bone kernel) and 153.88 (standard kernel). Decreasing radiation dose increased density and noise regardless of reconstruction technique and kernel. The effect of reconstruction technique on density and noise depends on the reconstruction kernel used. • Ultra-low-dose MDCT protocols allowed more than 90 % reductions in dose. • Decreasing the dose generally increased density and noise. • Effect of IRT on density and noise varies with reconstruction kernel. • Accuracy of low-dose protocols for interpretation of bony anatomy not known. • Effect of low doses on accuracy of computer-aided design models unknown.

  20. Effects of background noise on total noise annoyance

    Science.gov (United States)

    Willshire, K. F.

    1987-01-01

    Two experiments were conducted to assess the effects of combined community noise sources on annoyance. The first experiment baseline relationships between annoyance and noise level for three community noise sources (jet aircraft flyovers, traffic and air conditioners) presented individually. Forty eight subjects evaluated the annoyance of each noise source presented at four different noise levels. Results indicated the slope of the linear relationship between annoyance and noise level for the traffic noise was significantly different from that of aircraft and of air conditioner noise, which had equal slopes. The second experiment investigated annoyance response to combined noise sources, with aircraft noise defined as the major noise source and traffic and air conditioner noise as background noise sources. Effects on annoyance of noise level differences between aircraft and background noise for three total noise levels and for both background noise sources were determined. A total of 216 subjects were required to make either total or source specific annoyance judgements, or a combination of the two, for a wide range of combined noise conditions.

  1. Detecting anthropogenic footprints in sea level rise: the role of complex colored noise

    Science.gov (United States)

    Dangendorf, Sönke; Marcos, Marta; Müller, Alfred; Zorita, Eduardo; Jensen, Jürgen

    2015-04-01

    While there is scientific consensus that global mean sea level (MSL) is rising since the late 19th century, it remains unclear how much of this rise is due to natural variability or anthropogenic forcing. Uncovering the anthropogenic contribution requires profound knowledge about the persistence of natural MSL variations. This is challenging, since observational time series represent the superposition of various processes with different spectral properties. Here we statistically estimate the upper bounds of naturally forced centennial MSL trends on the basis of two separate components: a slowly varying volumetric (mass and density changes) and a more rapidly changing atmospheric component. Resting on a combination of spectral analyses of tide gauge records, ocean reanalysis data and numerical Monte-Carlo experiments, we find that in records where transient atmospheric processes dominate, the persistence of natural volumetric changes is underestimated. If each component is assessed separately, natural centennial trends are locally up to ~0.5 mm/yr larger than in case of an integrated assessment. This implies that external trends in MSL rise related to anthropogenic forcing might be generally overestimated. By applying our approach to the outputs of a centennial ocean reanalysis (SODA), we estimate maximum natural trends in the order of 1 mm/yr for the global average. This value is larger than previous estimates, but consistent with recent paleo evidence from periods in which the anthropogenic contribution was absent. Comparing our estimate to the observed 20th century MSL rise of 1.7 mm/yr suggests a minimum external contribution of at least 0.7 mm/yr. We conclude that an accurate detection of anthropogenic footprints in MSL rise requires a more careful assessment of the persistence of intrinsic natural variability.

  2. [HYGIENIC ASSESSMENT OF NOISE FACTOR OF THE LARGE CITY].

    Science.gov (United States)

    Chubirko, M L; Stepkin, Yu I; Seredenko, O V

    2015-01-01

    The article is devoted to the problem of the negative impact of traffic noise on the health and living conditions of the population in conditions of the large city. Every day on the streets there are appeared more and more different modes of transport, and to date almost all transportation network has reached his traffic performance. The increase in traffic noise certainly has an impact on the human body. The most common and intense noise is caused by the traffic of urban automobile and electric transport. This is explained by the existence of the heavy traffic (2-3 thousand crews/h) on almost all main roads in historically emerged parts of the city. In addition, sources of external noise in the city can be a railway running in residential zone, access roads, industrial enterprises, located in close proximity to residential areas and on the borders of residential zones, planes of military and civil aviation. For the evaluation of the different noises sound levels were measured with the use of sound level meters. The most common parameter for the assessment ofthe noise generatedfrom motor vehicles on residential areas and usedfor the noise characteristics of the traffic flows, is the equivalent sound level/A EQ dB. This parameter is used in the majority of normative-technical documentation as hygienic noise standard. With the aim of the assessment of noise exposure there were selected 122 control points at intersections of roads of different traffic performance where there were made instrumental measurements the equivalent sound level, followed by its comparison with permissible levels.

  3. The influence of road traffic noise on sleep

    Science.gov (United States)

    Eberhardt, J. L.

    1988-12-01

    The influence of road traffic noise on the sleep of adults and 6-11 year old children was studied by using electrophysiological methods. Young adults, unaccustomed to traffic noise, were disturbed by continuous and intermittent traffic noise at 45 dB(A). No sleep disturbances were found for continuous traffic noise at 36 dB(A). Car passages with a peak noise level of 55 dB(A) caused awakenings. The equivalent sound pressure level ( Leq) did not correlate with sleep disturbance effects. A better noise dose description was found in the number of vehicles per night that made most noise. Children wer about 10 dB(A) less sensitive than adults to awakening reactions, and even less sensitive with respect to disturbances of REM sleep and deep sleep. Total habituation to road traffic noise did not occur, even after at least one year of exposure. Sound reduction in the bedroom induced increased amounts of deep sleep for adults and reduced falling-asleep time for children. Road traffic noise during the first hours of a night's sleep tended to disturb sleep more than when it ocurred later in the night, the main effects being a reduction of the total amount of REM sleep during the night and an increased duration of intermittent wakefulness during the hours of exposure.

  4. Aircrafts' taxi noise emission

    NARCIS (Netherlands)

    Asensio, C.; Pagan Munoz, Raul; López, J.M.

    2008-01-01

    An investigation has been conducted, with the objective of creating a database of inputs that can be used with noise prediction software, to evaluate noise of aircraft taxing movements and community noise exposure levels. The acoustic consultant can use these data with any of the software packages,

  5. Urban Noise Recorded by Stationary Monitoring Stations

    Science.gov (United States)

    Bąkowski, Andrzej; Radziszewski, Leszek; Dekýš, Vladimir

    2017-10-01

    The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads in the town in the direction of Łódź and Lublin. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The agreement of the distribution of the variable under analysis with normal distribution was evaluated. It was demonstrated that in most cases (for both roads) there was sufficient evidence to reject the null hypothesis at the significance level of 0.05. It was noted that compared with Łódź Road, in the case of Lublin Road data, more cases were recorded for which the null hypothesis could not be rejected. Uncertainties of the equivalent sound level measurements were compared within the periods under analysis. The standard deviation, coefficient of variation, the positional coefficient of variation, the quartile deviation was proposed for performing a comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes and time intervals. The differences concerned the values of uncertainties and coefficients of variation of the equivalent sound levels.

  6. Quantitative comparisons of genotoxic effects of atomic energy and fossil-fuelled energy. Rad-equivalences for ethylene, ethylene oxide and formaldehyde - consequences for decisions at Government level

    International Nuclear Information System (INIS)

    Latarjet, R.; Averbeck, D.; Levy, S.; Poirier, V.

    1982-01-01

    Rad-equivalences have been determined on the basis of data on the genotoxic effects of low linear energy transfer ionizing radiation and of three chemical pollutants - ethylene, ethylene oxide and formaldehyde - emitted from energy-producing power plants. In the case of ethylene and its metabolite, ethylene oxide, the conditions were particularly favourable because the equivalences could be based on the induction of total mutations in the mouse, which is the same genetic end-point used for the assessment of radiation risks. Once established, the rad-equivalences were used (a) to extrapolate the rules adopted for radiation to each of these two compounds and (b) to make recommendations for exposed workers at 'hot spots' and for the general population. Measurements of ethylene in power plants and in the atmosphere of Paris have indicated that in most cases the measured values fall within the recommended values. However, pollution by ethylene oxide in cold sterilization units should be reduced. Rad-equivalences obtained for lethal effects, and for the induction of chromosome aberrations by formaldehyde in human cells in vitro, suggest that the maximum admissible concentrations are far too high in most countries and must be reconsidered. In France, the Ministry of Health is taking the rad-equivalences into consideration for the preparation of a law regulating pollution by ethylene and ethylene oxide - as a first step. These results show that rad-equivalences can be used for risk assessments of genotoxic effects from power plants and that decisions can be made by extrapolating the rules adopted for radiation protection to some chemical mutagens, when certain strict conditions are fulfilled. (author)

  7. Integration and comparison of assessment and modeling of road traffic noise in Baripada town, India

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Swain, Bijay [Department of Environmental Science, Utkal University, Bhubaneswar-751004, Odisha (India); Goswami, Shreerup [Department of Geology, Ravenshaw University, Cuttack-753003, Odisha (India)

    2013-07-01

    The road traffic is the predominant source of noise pollution in urban areas. Despite enactment of legislations and despite effort from Government level to abate vehicle noise, the noise exposure of people of India due to road traffic has hardly changed, but has increased day by day due to growth of vehicular population. Thus, an attempt had been made to assess the noise level in 12 different squares (major intersection points) of Baripada town during four different specified times (7-10 a.m., 11 a.m.-2 p.m., 3-6 p.m., 7-10 p.m.). The equivalent noise levels of all the 12 squares were found to be much beyond the permissible limit (70 dB during day time). Noise descriptors such as L10, L50, L90, Leq, TNI (Traffic Noise Index), NPL (Noise Pollution Level) and NC (Noise climate) were assessed to reveal the extent of noise pollution due to heavy traffic in this town. It is pertinent to mention here that even the minimum Leq and NPL values were more than 70.9 dB and 88.4 dB, respectively. Chi-square (X2) test was also computed for investigated squares at different times to infer the level of significance. The test depicts that the noise levels of different squares do not differ significantly at the peak hour. The prediction model was used in the present study to predict equivalent noise levels. Comparison of predicted equivalent noise level with that of the actual measured data demonstrated that the model used for the prediction has the ability to calibrate the multi-component traffic noise and yield reliable results close to that by direct measurement. Episodic and impulsive noise levels by the air-horn of motor vehicles in Baripada were also appraised and were more than the permissible limit. Though, the dimension of the traffic generated noise pollution in Baripada was not so alarming like other towns of India, a preliminary public health survey has also been carried out.

  8. Noise exposure during ambulance flights and repatriation operations.

    Science.gov (United States)

    Küpper, Thomas E; Zimmer, Bernd; Conrad, Gerson; Jansing, Paul; Hardt, Aline

    2010-01-01

    Although ambulance flights are routine work and thousands of employees work in repatriation organizations, there is no data on noise exposure which may be used for preventive advice. We investigated the noise exposure of crews working in ambulance flight organizations for international patient repatriation to get the data for specific guidelines concerning noise protection. Noise levels inside Learjet 35A, the aircraft type which is most often used for repatriation operations, were collected from locations where flight crews typically spend their time. A sound level meter class 1 meeting the DIN IEC 651 requirements was used for noise measurements, but several factors during the real flight situations caused a measurement error of ~3%. Therefore, the results fulfill the specifications for class 2. The data was collected during several real repatriation operations and was combined with the flight data (hours per day) regarding the personnel to evaluate the occupationally encountered equivalent noise level according to DIN 45645-2. The measured noise levels were safely just below the 85 dB(A) threshold and should not induce permanent threshold shifts, provided that additional high noise exposure by non-occupational or private activities was avoided. As the levels of the noise produced by the engines outside the cabin are significantly above the 85 dB(A) threshold, the doors of the aircraft must be kept closed while the engines are running, and any activity performed outside the aircraft - or with the doors opened while the engines are running - must be done with adequate noise protection. The new EU noise directive (2003/10/EG) states that protective equipment must be made available to the aircrew to protect their hearing, though its use is not mandatory.

  9. The Preparation for the Equivalence Examinations, First and Second Levels in the State of Sao Paulo, Brazil: Traditional Means and Educational Media.

    Science.gov (United States)

    Gatti, Bernardete A.

    1988-01-01

    Yearly in Sao Paulo (Brazil), official external examinations allow students outside the regular school system to obtain a certificate of education equivalent to grade 8 or 11. A television program that prepares candidates for the examinations and other forms of preparation are compared, using data collected for three years. (TJH)

  10. Evaluation and interconversion of various indicator PCB schemes for ∑PCB and dioxin-like PCB toxic equivalent levels in fish.

    Science.gov (United States)

    Gandhi, Nilima; Bhavsar, Satyendra P; Reiner, Eric J; Chen, Tony; Morse, Dave; Arhonditsis, George B; Drouillard, Ken G

    2015-01-06

    Polychlorinated biphenyls (PCBs) remain chemicals of concern more than three decades after the ban on their production. Technical mixture-based total PCB measurements are unreliable due to weathering and degradation, while detailed full congener specific measurements can be time-consuming and costly for large studies. Measurements using a subset of indicator PCBs (iPCBs) have been considered appropriate; however, inclusion of different PCB congeners in various iPCB schemes makes it challenging to readily compare data. Here, using an extensive data set, we examine the performance of existing iPCB3 (PCB 138, 153, and 180), iPCB6 (iPCB3 plus 28, 52, and 101) and iPCB7 (iPCB6 plus 118) schemes, and new iPCB schemes in estimating total of PCB congeners (∑PCB) and dioxin-like PCB toxic equivalent (dlPCB-TEQ) concentrations in sport fish fillets and the whole body of juvenile fish. The coefficients of determination (R(2)) for regressions conducted using logarithmically transformed data suggest that inclusion of an increased number of PCBs in an iPCB improves relationship with ∑PCB but not dlPCB-TEQs. Overall, novel iPCB3 (PCB 95, 118, and 153), iPCB4 (iPCB3 plus 138) and iPCB5 (iPCB4 plus 110) presented in this study and existing iPCB6 and iPCB7 are the most optimal indicators, while the current iPCB3 should be avoided. Measurement of ∑PCB based on a more detailed analysis (50+ congeners) is also overall a good approach for assessing PCB contamination and to track PCB origin in fish. Relationships among the existing and new iPCB schemes have been presented to facilitate their interconversion. The iPCB6 equiv levels for the 6.5 and 10 pg/g benchmarks of dlPCB-TEQ05 are about 50 and 120 ng/g ww, respectively, which are lower than the corresponding iPCB6 limits of 125 and 300 ng/g ww set by the European Union.

  11. Equivalence principles and electromagnetism

    Science.gov (United States)

    Ni, W.-T.

    1977-01-01

    The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

  12. Completion of Level 4 Milestone M4AT-15OR2301039 for the Johnson Noise Thermometry for Drift-free Temperature Measurements Work Package AT-15OR230103

    Energy Technology Data Exchange (ETDEWEB)

    Britton Jr, Charles L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-14

    This memorandum constitutes our September 2015 level 4 milestone for the project entitled “Johnson Noise Thermometry for Drift-free Temperature Measurements” and satisfies the Milestone/Activity (Conclude HFIR field demonstration of JNT prototype). The progress summary describes the work performed to complete the subject milestone.

  13. Erratum: Correction to Table 3, in: Equivalent threshold sound pressure levels (ETSPL) for Sennheiser HDA 280 supra-aural audiometric earphones in the frequency range 125 Hz to 8000 Hz (International Journal of Audiology (2009) 48 (271-276))

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2014-01-01

    The main results in Poulsen & Oakley (2009) are given as the equivalent threshold sound pressure level, ETSPL, measured in an acoustic coupler specifi ed in IEC 60318-3. These results are all correct. The ETSPL values for the ear simulator specifi ed in IEC 60318-1 were calculated from acoustic...

  14. Effects of a traffic noise background on judgements of aircraft noise

    Science.gov (United States)

    Powell, C. A.; Rice, C. G.

    1974-01-01

    A study was conducted in which subjects judged aircraft noises in the presence of road traffic background noise. Two different techniques for presenting the background noises were evaluated. For one technique, the background noise was continuous over the whole of a test session. For the other, the background noise was changed with each aircraft noise. A range of aircraft noise levels and traffic noise levels were presented to simulate typical indoor levels.

  15. Active Noise Control for Dishwasher noise

    Science.gov (United States)

    Lee, Nokhaeng; Park, Youngjin

    2016-09-01

    The dishwasher is a useful home appliance and continually used for automatically washing dishes. It's commonly placed in the kitchen with built-in style for practicality and better use of space. In this environment, people are easily exposed to dishwasher noise, so it is an important issue for the consumers, especially for the people living in open and narrow space. Recently, the sound power levels of the noise are about 40 - 50 dBA. It could be achieved by removal of noise sources and passive means of insulating acoustical path. For more reduction, such a quiet mode with the lower speed of cycle has been introduced, but this deteriorates the washing capacity. Under this background, we propose active noise control for dishwasher noise. It is observed that the noise is propagating mainly from the lower part of the front side. Control speakers are placed in the part for the collocation. Observation part of estimating sound field distribution and control part of generating the anti-noise are designed for active noise control. Simulation result shows proposed active noise control scheme could have a potential application for dishwasher noise reduction.

  16. Development of Airport Noise Mapping using Matlab Software (Case Study: Adi Soemarmo Airport - Boyolali, Indonesia)

    Science.gov (United States)

    Andarani, Pertiwi; Setiyo Huboyo, Haryono; Setyanti, Diny; Budiawan, Wiwik

    2018-02-01

    Noise is considered as one of the main environmental impact of Adi Soemarmo International Airport (ASIA), the second largest airport in Central Java Province, Indonesia. In order to manage the noise of airport, airport noise mapping is necessary. However, a model that requires simple input but still reliable was not available in ASIA. Therefore, the objective of this study are to develop model using Matlab software, to verify its reliability by measuring actual noise exposure, and to analyze the area of noise levels‥ The model was developed based on interpolation or extrapolation of identified Noise-Power-Distance (NPD) data. In accordance with Indonesian Government Ordinance No.40/2012, the noise metric used is WECPNL (Weighted Equivalent Continuous Perceived Noise Level). Based on this model simulation, there are residence area in the region of noise level II (1.912 km2) and III (1.16 km2) and 18 school buildings in the area of noise levels I, II, and III. These land-uses are actually prohibited unless noise insulation is equipped. The model using Matlab in the case of Adi Soemarmo International Airport is valid based on comparison of the field measurement (6 sampling points). However, it is important to validate the model again once the case study (the airport) is changed.

  17. Noise suppression in duct

    International Nuclear Information System (INIS)

    Ahmed, A.; Barfeh, M.A.G.

    2001-01-01

    In air-conditioning system the noise generated by supply fan is carried by conditioned air through the ductwork. The noise created in ductwork run may be transmission, regenerative and ductborne. Transmission noise is fan noise, regenerative noise is due to turbulence in flow and ductborne noise is the noise radiating from duct to surroundings. Some noise is attenuated in ducts also but if noise level is high then it needs to be attenuated. A simple mitre bend can attenuate-noise. This principle is extended to V and M-shape ducts with inside lining of fibreglass, which gave maximum attenuation of 77 dB and 62 dB respectively corresponding to 8 kHz frequency as compared to mitre, bend giving maximum 18 dB attenuation. Sound level meter measured sound levels with octave band filter and tests were conducted in anechoic room. A V-shape attenuator can be used at fan outlet and high frequency noise can be minimized greatly. (author)

  18. Combat aircraft noise

    Science.gov (United States)

    Sgarbozza, M.; Depitre, A.

    1992-04-01

    A discussion of the characteristics and the noise levels of combat aircraft and of a transport aircraft in taking off and landing are presented. Some methods of noise reduction are discussed, including the following: operational anti-noise procedures; and concepts of future engines (silent post-combustion and variable cycle). Some measurement results concerning the noise generated in flight at great speeds and low altitude will also be examined. Finally, the protection of the environment of French air bases against noise will be described and the possibilities of regulation examined.

  19. Effect of training data size and noise level on support vector machines virtual screening of genotoxic compounds from large compound libraries.

    Science.gov (United States)

    Kumar, Pankaj; Ma, Xiaohua; Liu, Xianghui; Jia, Jia; Bucong, Han; Xue, Ying; Li, Ze Rong; Yang, Sheng Yong; Wei, Yu Quan; Chen, Yu Zong

    2011-05-01

    Various in vitro and in-silico methods have been used for drug genotoxicity tests, which show limited genotoxicity (GT+) and non-genotoxicity (GT-) identification rates. New methods and combinatorial approaches have been explored for enhanced collective identification capability. The rates of in-silco methods may be further improved by significantly diversified training data enriched by the large number of recently reported GT+ and GT- compounds, but a major concern is the increased noise levels arising from high false-positive rates of in vitro data. In this work, we evaluated the effect of training data size and noise level on the performance of support vector machines (SVM) method known to tolerate high noise levels in training data. Two SVMs of different diversity/noise levels were developed and tested. H-SVM trained by higher diversity higher noise data (GT+ in any in vivo or in vitro test) outperforms L-SVM trained by lower noise lower diversity data (GT+ in in vivo or Ames test only). H-SVM trained by 4,763 GT+ compounds reported before 2008 and 8,232 GT- compounds excluding clinical trial drugs correctly identified 81.6% of the 38 GT+ compounds reported since 2008, predicted 83.1% of the 2,008 clinical trial drugs as GT-, and 23.96% of 168 K MDDR and 27.23% of 17.86M PubChem compounds as GT+. These are comparable to the 43.1-51.9% GT+ and 75-93% GT- rates of existing in-silico methods, 58.8% GT+ and 79% GT- rates of Ames method, and the estimated percentages of 23% in vivo and 31-33% in vitro GT+ compounds in the "universe of chemicals". There is a substantial level of agreement between H-SVM and L-SVM predicted GT+ and GT- MDDR compounds and the prediction from TOPKAT. SVM showed good potential in identifying GT+ compounds from large compound libraries based on higher diversity and higher noise training data.

  20. Comparison of Annoyance from Railway Noise and Railway Vibration.

    Science.gov (United States)

    Ögren, Mikael; Gidlöf-Gunnarsson, Anita; Smith, Michael; Gustavsson, Sara; Persson Waye, Kerstin

    2017-07-19

    The aim of this study is to compare vibration exposure to noise exposure from railway traffic in terms of equal annoyance, i.e., to determine when a certain noise level is equally annoying as a corresponding vibration velocity. Based on questionnaire data from the Train Vibration and Noise Effects (TVANE) research project from residential areas exposed to railway noise and vibration, the dose response relationship for annoyance was estimated. By comparing the relationships between exposure and annoyance for areas both with and without significant vibration exposure, the noise levels and vibration velocities that had an equal probability of causing annoyance was determined using logistic regression. The comparison gives a continuous mapping between vibration velocity in the ground and a corresponding noise level at the facade that are equally annoying. For equivalent noise level at the facade compared to maximum weighted vibration velocity in the ground the probability of annoyance is approximately 20% for 59 dB or 0.48 mm/s, and about 40% for 63 dB or 0.98 mm/s.

  1. White-crowned sparrow males show immediate flexibility in song amplitude but not in song minimum frequency in response to changes in noise levels in the field.

    Science.gov (United States)

    Derryberry, Elizabeth P; Gentry, Katherine; Derryberry, Graham E; Phillips, Jennifer N; Danner, Raymond M; Danner, Julie E; Luther, David A

    2017-07-01

    The soundscape acts as a selective agent on organisms that use acoustic signals to communicate. A number of studies document variation in structure, amplitude, or timing of signal production in correspondence with environmental noise levels thus supporting the hypothesis that organisms are changing their signaling behaviors to avoid masking. The time scale at which organisms respond is of particular interest. Signal structure may evolve across generations through processes such as cultural or genetic transmission. Individuals may also change their behavior during development (ontogenetic change) or in real time (i.e., immediate flexibility). These are not mutually exclusive mechanisms, and all must be investigated to understand how organisms respond to selection pressures from the soundscape. Previous work on white-crowned sparrows ( Zonotrichia leucophrys ) found that males holding territories in louder areas tend to sing higher frequency songs and that both noise levels and song frequency have increased over time (30 years) in urban areas. These previous findings suggest that songs are changing across generations; however, it is not known if this species also exhibits immediate flexibility. Here, we conducted an exploratory, observational study to ask whether males change the minimum frequency of their song in response to immediate changes in noise levels. We also ask whether males sing louder, as increased minimum frequency may be physiologically linked to producing sound at higher amplitudes, in response to immediate changes in environmental noise. We found that territorial males adjust song amplitude but not minimum frequency in response to changes in environmental noise levels. Our results suggest that males do not show immediate flexibility in song minimum frequency, although experimental manipulations are needed to test this hypothesis further. Our work highlights the need to investigate multiple mechanisms of adaptive response to soundscapes.

  2. Spatial traffic noise pollution assessment – A case study

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Monazzam

    2015-06-01

    Full Text Available Objectives: Spatial assessment of traffic noise pollution intensity will provide urban planners with approximate estimation of citizens exposure to impermissible sound levels. They could identify critical noise pollution areas wherein noise barriers should be embedded. The present study aims at using the Geographic Information System (GIS to assess spatial changes in traffic noise pollution in Tehran, the capital of Iran, and the largest city in the Middle East. Material and Methods: For this purpose, while measuring equivalent sound levels at different time periods of a day and different days of a week in District 14 of Tehran, wherein there are highways and busy streets, the geographic coordination of the measurement points was recorded at the stations. The obtained results indicated that the equivalent sound level did not show a statistically significant difference between weekdays, and morning, afternoon and evening hours as well as time intervals of 10 min, 15 min and 30 min. Then, 91 stations were selected in the target area and equivalent sound level was measured for each station on 3 occasions of the morning (7:00–9:00 a.m., afternoon (12.00–3:00 p.m. and evening (5:00–8:00 p.m. on Saturdays to Wednesdays. Results: As the results suggest, the maximum equivalent sound level (Leq was reported from Basij Highway, which is a very important connecting thoroughfare in the district, and was equal to 84.2 dB(A, while the minimum equivalent sound level (Leq, measured in the Fajr Hospital, was equal to 59.9 dB(A. Conclusions: The average equivalent sound level was higher than the national standard limit at all stations. The use of sound walls in Highways Basij and Mahallati as well as widening the Streets 17th Shahrivar, Pirouzi and Khavaran, benchmarked on a map, were recommended as the most effective mitigation measures. Additionally, the research findings confirm the outstanding applicability of the Geographic Information System in

  3. Spatial traffic noise pollution assessment - A case study.

    Science.gov (United States)

    Monazzam, Mohammad Reza; Karimi, Elham; Abbaspour, Majid; Nassiri, Parvin; Taghavi, Lobat

    2015-01-01

    Spatial assessment of traffic noise pollution intensity will provide urban planners with approximate estimation of citizens exposure to impermissible sound levels. They could identify critical noise pollution areas wherein noise barriers should be embedded. The present study aims at using the Geographic Information System (GIS) to assess spatial changes in traffic noise pollution in Tehran, the capital of Iran, and the largest city in the Middle East. For this purpose, while measuring equivalent sound levels at different time periods of a day and different days of a week in District 14 of Tehran, wherein there are highways and busy streets, the geographic coordination of the measurement points was recorded at the stations. The obtained results indicated that the equivalent sound level did not show a statistically significant difference between weekdays, and morning, afternoon and evening hours as well as time intervals of 10 min, 15 min and 30 min. Then, 91 stations were selected in the target area and equivalent sound level was measured for each station on 3 occasions of the morning (7:00-9:00 a.m.), afternoon (12.00-3:00 p.m.) and evening (5:00-8:00 p.m.) on Saturdays to Wednesdays. As the results suggest, the maximum equivalent sound level (Leq) was reported from Basij Highway, which is a very important connecting thoroughfare in the district, and was equal to 84.2 dB(A), while the minimum equivalent sound level (Leq), measured in the Fajr Hospital, was equal to 59.9 dB(A). The average equivalent sound level was higher than the national standard limit at all stations. The use of sound walls in Highways Basij and Mahallati as well as widening the Streets 17th Shahrivar, Pirouzi and Khavaran, benchmarked on a map, were recommended as the most effective mitigation measures. Additionally, the research findings confirm the outstanding applicability of the Geographic Information System in handling noise pollution data towards depicting noise pollution intensity caused

  4. Noise in the operating room

    DEFF Research Database (Denmark)

    Hasfeldt-Hansen, Dorthe; Lærkner, Eva Ann; Birkelund, Regner

    2010-01-01

    Because noise is a general stressor, noise in the OR should be avoided whenever possible. This article presents the results of a review of the research literature on the topic of noise in the OR. A systematic literature search was conducted. Eighteen relevant articles were identified...... and categorized as follows: noise levels, noise sources, staff performances, and patient’s perception of noise. Each study was assessed according to the strength of the evidence and the quality of the study. Noise levels in the OR in general exceed recommended levels, and the noise sources are related...... to equipment and staff behavior. The main effect of noise on staff performances is related to impaired communication, resulting in a negative effect on patient safety. The literature on patients’ perception of noise is both limited and inconsistent, and more research on this topic is needed....

  5. Ambient Noise in an Urbanized Tidal Channel

    Science.gov (United States)

    Bassett, Christopher

    levels that shows good agreement with 85% of the temporal data. Bed stresses associated with currents can produce propagating ambient noise by mobilizing sediments. The strength of the tidal currents in northern Admiralty Inlet produces bed stresses in excess of 20 Pa. Significant increases in noise levels at frequencies from 4-30 kHz, with more modest increases noted from 1-4 kHz, are attributed to mobilized sediments. Sediment-generated noise during strong currents masks background noise from other sources, including vessel traffic. Inversions of the acoustic spectra for equivalent grain sizes are consistent with qualitative observations of the seabed composition. Bed stress calculations using log layer, Reynolds stress, and inertial dissipation techniques generally agree well and are used to estimate the shear stresses at which noise levels increase for different grain sizes. Ambient noise levels in one-third octave bands with center frequencies from 1 kHz to 25 kHz are dominated by sediment-generated noise and can be accurately predicted using the near-bed current velocity above a critical threshold. When turbulence is advected over a pressure sensitive transducer, the turbulent pressure fluctuations can be measured as noise, though these pressure fluctuations are not propagating sound and should not be interpreted as ambient noise. Based on measurements in both Admiralty Inlet, Puget Sound and the Chacao Channel, Chile, two models are developed for flow-noise. The first model combined measurements of mean current velocities and turbulence and agrees well with data from both sites. The second model uses scaling arguments to model the flow-noise based solely on the mean current velocity. This model agrees well with the data from the Chacao Channel but performs poorly in Admiralty Inlet, a difference attributed to differences turbulence production mechanisms. At both sites, the spectral slope of flow noise follows a f-3.2 dependence, suggesting partial cancellation of

  6. ENHANCEMENT OF NOISE LEVEL IN URBAN ENVIRONMENT DUE TOURIST ACTIVITIES: A CASE STUDY IN THE CITY OF CAMPOS DO JORDÃO

    Directory of Open Access Journals (Sweden)

    Luiz Antonio Brito

    2014-12-01

    Full Text Available The excess of noise in large cities is a recurrent situation which creates irritability, loss of efficiency at work and loss of life quality, in such way that the silence and the tranquility of smaller cities end up being a touristic appeal. But, at the same time, the touristic activities have great potential of generating noise energy, which leads to a conflicting situation. The city of Campos de Jordão, nationally known for its cool climate, European architecture and sophisticated gastronomy, is popular among people who seek both tranquility and entertainment. The objective of this assignment is to evaluate the urban impact created by the increase of noise energy due to touristic activities in the city of Campos do Jordão. Thus, measurement of sound pressure levels were carried out on holidays and working days in 15 chosen spots. The results showed a considerable elevation of noise levels, even in areas away from touristic zones. This condition tends to move hotels and inns away from the touristic zone of the city, which demands investments in infrastructure, burdening the local government.

  7. Waste Determination Equivalency - 12172

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Rebecca D. [Savannah River Remediation (United States)

    2012-07-01

    The Savannah River Site (SRS) is a Department of Energy (DOE) facility encompassing approximately 800 square kilometers near Aiken, South Carolina which began operations in the 1950's with the mission to produce nuclear materials. The SRS contains fifty-one tanks (2 stabilized, 49 yet to be closed) distributed between two liquid radioactive waste storage facilities at SRS containing carbon steel underground tanks with storage capacities ranging from 2,800,000 to 4,900,000 liters. Treatment of the liquid waste from these tanks is essential both to closing older tanks and to maintaining space needed to treat the waste that is eventually vitrified or disposed of onsite. Section 3116 of the Ronald W. Reagan National Defense Authorization Act of Fiscal Year 2005 (NDAA) provides the Secretary of Energy, in consultation with the Nuclear Regulatory Commission (NRC), a methodology to determine that certain waste resulting from prior reprocessing of spent nuclear fuel are not high-level radioactive waste if it can be demonstrated that the waste meets the criteria set forth in Section 3116(a) of the NDAA. The Secretary of Energy, in consultation with the NRC, signed a determination in January 2006, pursuant to Section 3116(a) of the NDAA, for salt waste disposal at the SRS Saltstone Disposal Facility. This determination is based, in part, on the Basis for Section 3116 Determination for Salt Waste Disposal at the Savannah River Site and supporting references, a document that describes the planned methods of liquid waste treatment and the resulting waste streams. The document provides descriptions of the proposed methods for processing salt waste, dividing them into 'Interim Salt Processing' and later processing through the Salt Waste Processing Facility (SWPF). Interim Salt Processing is separated into Deliquification, Dissolution, and Adjustment (DDA) and Actinide Removal Process/Caustic Side Solvent Extraction Unit (ARP/MCU). The Waste Determination was signed

  8. Cost-Benefit Analysis of Rail-Noise Mitigation Programmes at European Level: Methodological Innovations from EURANO to STAIRRS

    OpenAIRE

    Aude Lenders; Nancy Da Silva; Walter Hecq; Baumgartner Thomas

    2001-01-01

    The STAIRRS project (2000-2002) is a follow-up of EURANO [1] and a Swiss study [2], in which the authors evaluated the efficiency of noise reduction measures in two European freight corridors. STAIRRS includes a cost-benefit analysis based on about 10,000 km of track modelled in seven countries. The benefits are defined in terms of the dB(A) experienced by those living in the rail corridors modelled. They are to be weighted by the number of persons benefiting each year from a noise reduction ...

  9. Quantum Noise

    International Nuclear Information System (INIS)

    Beenakker, C W J

    2005-01-01

    Quantum Noise is advertised as a handbook, and this is indeed how it functions for me these days: it is a book that I keep within hand's reach, ready to be consulted on the proper use of quantum stochastic methods in the course of my research on quantum dots. I should point out that quantum optics, the target field for this book, is not my field by training. So I have much to learn, and find this handbook to be a reliable and helpful guide. Crispin Gardiner previously wrote the Handbook of Stochastic Methods (also published by Springer), which provides an overview of methods in classical statistical physics. Quantum Noise, written jointly with Peter Zoller, is the counterpart for quantum statistical physics, and indeed the two books rely on each other by frequent cross referencing. The fundamental problem addressed by Quantum Noise is how the quantum dynamics of an open system can be described statistically by treating the environment as a source of noise. This is a general problem in condensed matter physics (in particular in the context of Josephson junctions) and in quantum optics. The emphasis in this book in on the optical applications (for condensed matter applications one could consult Quantum Dissipative Systems by Ulrich Weiss, published by World Scientific). The optical applications centre around the interaction of light with atoms, where the atoms represent the open system and the light is the noisy environment. A complete description of the production and detection of non-classical states of radiation (such as squeezed states) can be obtained using one of the equivalent quantum stochastic formulations: the quantum Langevin equation for the field operators (in either the Ito or the Stratonovich form), the Master equation for the density matrix, or the stochastic Schroedinger equation for the wave functions. Each formulation is fully developed here (as one would expect from a handbook), with detailed instructions on how to go from one to the other. The

  10. Road Traffic Noise Exposure in Gothenburg 1975-2010.

    Directory of Open Access Journals (Sweden)

    Mikael Ögren

    Full Text Available Traffic noise exposure within a city varies over time and space. In this study, we developed a modified noise calculation method and used this method together with population and traffic data to estimate the time trend of noise exposure for the population in Gothenburg, Sweden, from 1975 to 2010. The noise calculation method was based on the standard Nordic method for road traffic noise with modifications using area-level statistics for population and building structures instead of precise geocoding of each inhabitant. Noise emission per vehicle was assumed to be constant over the period. The results show an increase in noise exposure over time. The number of inhabitants exposed at an equivalent level above 55 dB increased from 93000 to 146000 inhabitants between 1975 and 2010, and the percentage of the population exposed at this level increased from 22% to 29% over the same period. Traffic increase (1.4% per year and population increase/concentration (0.50% per year were approximately equally important factors behind this increase in exposure.

  11. Nível de ruídos em uma unidade de cuidados intensivos pediátricos Noise level in a pediatric intensive care unit

    Directory of Open Access Journals (Sweden)

    Werther B. Carvalho

    2005-12-01

    Full Text Available OBJETIVO: Verificar o nível de ruídos em uma unidade de cuidados intensivos pediátricos. MÉTODOS: Estudo observacional e prospectivo realizado em uma unidade de cuidados intensivos pediátricos de 10 leitos de um hospital universitário da cidade de São Paulo, Brasil. Os níveis de ruídos foram medidos por meio de equipamento instalado no corredor de acesso à unidade de cuidados intensivos pediátricos, posto de enfermagem, duas salas com três e cinco leitos, bem como nas unidades de isolamento. O equipamento utilizado foi calibrado para registrar a pressão do som em dBA, durante 24 horas, por 6 dias. Os dados foram analisados de acordo com as curvas gráficas registradas pelo equipamento. RESULTADOS: Foi identificado um nível basal de ruídos de 60 a 70 dBA, com pico de 120 dBA. Os níveis mais elevados foram identificados no período diurno, decorrentes da atividade e comunicação dos profissionais. CONCLUSÃO: Os níveis de ruídos identificados excederam as recomendações do International Noise Council, da Organização Mundial da Saúde. A educação sobre os efeitos prejudiciais de ruídos na audição humana e sua relação com o estresse constituem as bases para a implementação de programas de redução de ruídos.OBJECTIVE: The purpose of this study was to verify the noise level at a PICU. METHODS: This prospective observational study was performed in a 10 bed PICU at a teaching hospital located in a densely populated district within the city of São Paulo, Brazil. Sound pressure levels (dBA were measured 24 hours during a 6-day period. Noise recording equipment was placed in the PICU access corridor, nursing station, two open wards with three and five beds, and in isolation rooms. The resulting curves were analyzed. RESULTS: A basal noise level variation between 60 and 70 dBA was identified, with a maximum level of 120 dBA. The most significant noise levels were recorded during the day and were produced by the staff

  12. Assessment of noise pollution in and around a sensitive zone in North India and its non-auditory impacts.

    Science.gov (United States)

    Khaiwal, Ravindra; Singh, Tanbir; Tripathy, Jaya Prasad; Mor, Suman; Munjal, Sanjay; Patro, Binod; Panda, Naresh

    2016-10-01

    Noise pollution in hospitals is recognized as a serious health hazard. Considering this, the current study aimed to map the noise pollution levels and to explore the self reported non-auditory effects of noise in a tertiary medical institute. The study was conducted in an 1800-bedded tertiary hospital where 27 sites (outdoor, indoor, road side and residential areas) were monitored for exposure to noise using Sound Level Meter for 24h. A detailed noise survey was also conducted around the sampling sites using a structured questionnaire to understand the opinion of the public regarding the impact of noise on their daily lives. The equivalent sound pressure level (Leq) was found higher than the permissible limits at all the sites both during daytime and night. The maximum equivalent sound pressure level (Lmax) during the day was observed higher (>80dB) at the emergency and around the main entrance of the hospital campus. Almost all the respondents (97%) regarded traffic as the major source of noise. About three-fourths (74%) reported irritation with loud noise whereas 40% of respondents reported headache due to noise. Less than one-third of respondents (29%) reported loss of sleep due to noise and 8% reported hypertension, which could be related to the disturbance caused due to noise. Noise levels in and around the hospital was well above the permissible standards. The recent Global Burden of Disease highlights the increasing risk of non communicable diseases. The non-auditory effects studied in the current work add to the risk factors associated with non communicable diseases. Hence, there is need to address the issue of noise pollution and associated health risks specially for vulnerable population. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Theory of Covariance Equivalent ARMAV Models of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Andersen, P.; Brincker, Rune; Kirkegaard, Poul Henning

    1996-01-01

    In this paper the theoretical background for using covariance equivalent ARMAV models in modal analysis is discussed. It is shown how to obtain a covariance equivalent ARMA model for a univariate linear second order continous-time system excited by Gaussian white noise. This result is generalized...

  14. Theory of Covariance Equivalent ARMAV Models of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Andersen, P.; Brincker, Rune; Kirkegaard, Poul Henning

    In this paper the theoretical background for using covariance equivalent ARMAV models in modal analysis is discussed. It is shown how to obtain a covariance equivalent ARMA model for a univariate linear second order continuous-time system excited by Gaussian white noise. This result is generalize...

  15. Managing Electrochemical Noise Data by Exception Application of an On Line EN Data Analysis Technique to Data From a High Level Nuclear Waste Tank

    International Nuclear Information System (INIS)

    EDGEMON, G.L.

    2003-01-01

    Electrochemical noise has been used a t the Hanford Site for a number of years to monitor in real time for pitting corrosion and stress corrosion cracking (SCC) mechanisms in high level nuclear waste tanks. Currently the monitoring technique has only been implemented on three of the 177 underground storage tanks on the site. Widespread implementation of the technique has been held back for of a number of reasons, including issues around managing the large volume of data associated with electrochemical noise and the complexity of data analysis. Expert review of raw current and potential measurements is the primary form of data analysis currently used at the Hanford site. This paper demonstrates the application of an on-line data filtering and analysis technique that could allow data from field applications of electrochemical noise to be managed by exception, transforming electrochemical noise data into a process parameter and focusing data analysis efforts on the important data. Results of the analysis demonstrate a data compression rate of 95%; that is, only 5% of the data would require expert analysis if such a technique were implemented. It is also demonstrated that this technique is capable of identifying key periods where localized corrosion activity is apparent

  16. The effects of acoustical refurbishment of classrooms on teachers’ perceived noise exposure and noise-related health symptoms

    DEFF Research Database (Denmark)

    Kristiansen, Jesper; Lund, Søren Peter; Persson, Roger

    2015-01-01

    lessons with circa 2 dB(A) in both schools. Conclusion: The acoustical refurbishment was associated with a reduction in classroom reverberation time and activity sound levels in both schools. The acoustical refurbishment was associated with a reduction in the teachers’ perceived noise exposure...... of RT and activity sound levels were measured before and after refurbishment. Data on perceived noise exposure, disturbance attributed to different noise sources, voice symptoms, and fatigue after work were collected over a year in a total of six consecutive questionnaires. Results: Refurbished......, the mean classroom reverberation time was 0.68 (school A) and 0.57 (school B) and 0.55 s in sham refurbished classrooms. After refurbishment, the RT was approximately 0.4 s in both schools. Activity sound level measurements confirmed that the intervention had reduced the equivalent sound levels during...

  17. Assessment of road traffic noise indices in urban residential areas of Klang Valley, Malaysia

    Science.gov (United States)

    Halim, Herni; Abdullah, Ramdzani; Nor, Mohd Jailani Mohd; Aziz, Hamidi Abdul; Rahman, Noorhazlinda Abd

    2017-10-01

    Traffic noise has been recognized as a serious threat to the quality of life in most industrialised nations. Klang valley is rapidly emerging as industrialized and urbanized city and has started facing severe noise pollution problems. Urban noise quality assessment is studied in three residential areas; Desa Tun Razak, Kinrara Court and Taman Sentul Utama. Noise pollution indices of L10, L50, L90, Lmax and Lmin as well as equivalent continuous noise level (Leq) were measured for all dwellings. Noise indices results illustrate that Desa Tun Razak recorded the highest values of noise levels among three studied sites. Results also indicate that the highest Leq of 75.7 dB(A) was observed in Desa Tun Razak followed by 74.3 dB(A) in Kinrara Court, and 72.1 dB(A) in Taman Sentul Utama. The noise assessment study clearly reveals the alarming condition of noise pollution in residential areas of Klang Valley as the noise level measured exceeded permissible limit by WHO and Malaysia Guidelines.

  18. Environmental noise pollution in the United States: developing an effective public health response.

    Science.gov (United States)

    Hammer, Monica S; Swinburn, Tracy K; Neitzel, Richard L

    2014-02-01

    Tens of millions of Americans suffer from a range of adverse health outcomes due to noise exposure, including heart disease and hearing loss. Reducing environmental noise pollution is achievable and consistent with national prevention goals, yet there is no national plan to reduce environmental noise pollution. We aimed to describe some of the most serious health effects associated with noise, summarize exposures from several highly prevalent noise sources based on published estimates as well as extrapolations made using these estimates, and lay out proven mechanisms and strategies to reduce noise by incorporating scientific insight and technological innovations into existing public health infrastructure. We estimated that 104 million individuals had annual LEQ(24) levels > 70 dBA (equivalent to a continuous average exposure level of >70 dBA over 24 hr) in 2013 and were at risk of noise-induced hearing loss. Tens of millions more may be at risk of heart disease, and other noise-related health effects. Direct regulation, altering the informational environment, and altering the built environment are the least costly, most logistically feasible, and most effective noise reduction interventions. Significant public health benefit can be achieved by integrating interventions that reduce environmental noise levels and exposures into the federal public health agenda.

  19. Effective dose equivalent

    International Nuclear Information System (INIS)

    Huyskens, C.J.; Passchier, W.F.

    1988-01-01

    The effective dose equivalent is a quantity which is used in the daily practice of radiation protection as well as in the radiation hygienic rules as measure for the health risks. In this contribution it is worked out upon which assumptions this quantity is based and in which cases the effective dose equivalent can be used more or less well. (H.W.)

  20. Characterization of revenue equivalence

    NARCIS (Netherlands)

    Heydenreich, B.; Müller, R.; Uetz, Marc Jochen; Vohra, R.

    2009-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called revenue equivalence. We give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The characterization holds

  1. Characterization of Revenue Equivalence

    NARCIS (Netherlands)

    Heydenreich, Birgit; Müller, Rudolf; Uetz, Marc Jochen; Vohra, Rakesh

    2008-01-01

    The property of an allocation rule to be implementable in dominant strategies by a unique payment scheme is called \\emph{revenue equivalence}. In this paper we give a characterization of revenue equivalence based on a graph theoretic interpretation of the incentive compatibility constraints. The

  2. On the operator equivalents

    International Nuclear Information System (INIS)

    Grenet, G.; Kibler, M.

    1978-06-01

    A closed polynomial formula for the qth component of the diagonal operator equivalent of order k is derived in terms of angular momentum operators. The interest in various fields of molecular and solid state physics of using such a formula in connection with symmetry adapted operator equivalents is outlined

  3. A system for evaluating the impact of noise pollution on the population's health.

    Science.gov (United States)

    Bressane, Adriano; Mochizuki, Patricia Satie; Caram, Rosana Maria; Roveda, José Arnaldo Frutuoso

    2016-05-01

    The aim of this study was to develop a support system for the evaluation of noise pollution, applied to the central urban area of Rio Claro, São Paulo State, Brazil. Data were obtained from noise measurements and interviews with the population, generating the following indicators: equivalent sound level (Leq ), traffic noise index (LTNI ), and a participatory diagnosis (Dp ), integrated through a fuzzy inference system (FIS). The proposed system allowed classifying the measurement points according to the degree of impact of noise pollution on the population's health (IPS ) in the study area. Impact was considered significant in 31.4% of the measurement points and very significant in 62.9%. The FIS can be adjusted to local conditions, allowing generalization and thus also supporting noise pollution evaluation and respective environmental noise management in other geographic areas.

  4. Thresholding of auditory cortical representation by background noise

    Science.gov (United States)

    Liang, Feixue; Bai, Lin; Tao, Huizhong W.; Zhang, Li I.; Xiao, Zhongju

    2014-01-01

    It is generally thought that background noise can mask auditory information. However, how the noise specifically transforms neuronal auditory processing in a level-dependent manner remains to be carefully determined. Here, with in vivo loose-patch cell-attached recordings in layer 4 of the rat primary auditory cortex (A1), we systematically examined how continuous wideband noise of different levels affected receptive field properties of individual neurons. We found that the background noise, when above a certain critical/effective level, resulted in an elevation of intensity threshold for tone-evoked responses. This increase of threshold was linearly dependent on the noise intensity above the critical level. As such, the tonal receptive field (TRF) of individual neurons was translated upward as an entirety toward high intensities along the intensity domain. This resulted in preserved preferred characteristic frequency (CF) and the overall shape of TRF, but reduced frequency responding range and an enhanced frequency selectivity for the same stimulus intensity. Such translational effects on intensity threshold were observed in both excitatory and fast-spiking inhibitory neurons, as well as in both monotonic and nonmonotonic (intensity-tuned) A1 neurons. Our results suggest that in a noise background, fundamental auditory representations are modulated through a background level-dependent linear shifting along intensity domain, which is equivalent to reducing stimulus intensity. PMID:25426029

  5. Effects of ocular aberrations on contrast detection in noise.

    Science.gov (United States)

    Liang, Bo; Liu, Rong; Dai, Yun; Zhou, Jiawei; Zhou, Yifeng; Zhang, Yudong

    2012-08-06

    We use adaptive optics (AO) techniques to manipulate the ocular aberrations and elucidate the effects of these ocular aberrations on contrast detection in a noisy background. The detectability of sine wave gratings at frequencies of 4, 8, and 16 circles per degree (cpd) was measured in a standard two-interval force-choice staircase procedure against backgrounds of various levels of white noise. The observer's ocular aberrations were either corrected with AO or left uncorrected. In low levels of external noise, contrast detection thresholds are always lowered by AO correction, whereas in high levels of external noise, they are generally elevated by AO correction. Higher levels of external noise are required to make this threshold elevation observable when signal spatial frequencies increase from 4 to 16 cpd. The linear-amplifier-model fit shows that mostly sampling efficiency and equivalent noise both decrease with AO correction. Our findings indicate that ocular aberrations could be beneficial for contrast detection in high-level noises. The implications of these findings are discussed.

  6. Thresholding of auditory cortical representation by background noise.

    Science.gov (United States)

    Liang, Feixue; Bai, Lin; Tao, Huizhong W; Zhang, Li I; Xiao, Zhongju

    2014-01-01

    It is generally thought that background noise can mask auditory information. However, how the noise specifically transforms neuronal auditory processing in a level-dependent manner remains to be carefully determined. Here, with in vivo loose-patch cell-attached recordings in layer 4 of the rat primary auditory cortex (A1), we systematically examined how continuous wideband noise of different levels affected receptive field properties of individual neurons. We found that the background noise, when above a certain critical/effective level, resulted in an elevation of intensity threshold for tone-evoked responses. This increase of threshold was linearly dependent on the noise intensity above the critical level. As such, the tonal receptive field (TRF) of individual neurons was translated upward as an entirety toward high intensities along the intensity domain. This resulted in preserved preferred characteristic frequency (CF) and the overall shape of TRF, but reduced frequency responding range and an enhanced frequency selectivity for the same stimulus intensity. Such translational effects on intensity threshold were observed in both excitatory and fast-spiking inhibitory neurons, as well as in both monotonic and nonmonotonic (intensity-tuned) A1 neurons. Our results suggest that in a noise background, fundamental auditory representations are modulated through a background level-dependent linear shifting along intensity domain, which is equivalent to reducing stimulus intensity.

  7. The impact of an urban park on air pollution and noise levels in the Mediterranean city of Tel-Aviv, Israel.

    Science.gov (United States)

    Cohen, Pninit; Potchter, Oded; Schnell, Izhak

    2014-12-01

    This study examines the influence of urban parks on air quality and noise in the city of Tel-Aviv, Israel, by investigation of an urban park, an urban square and a street canyon. Simultaneous monitoring of several air pollutants and noise levels were conducted. The results showed that urban parks can reduce NOx, CO and PM10 and increase O3 concentrations and that park's mitigation effect is greater at higher NOx and PM10 levels. During extreme events, mean values of 413 ppb NOx and 80 μG/m3 PM10 were measured in the street while mean values of 89 ppb NOx and 24 μG/m3 PM10 were measured in the park. Whereas summer highest O3 values of 84 ppb were measured in the street, 94 ppb were measured in the park. The benefit of the urban park in reducing NOx and PM10 concentrations is more significant than the disadvantage of increased O3 levels. Furthermore, urban parks can reduce noise by ∼5 dB(A). Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. The Assessment of Noise Exposure and Noise Annoyance at a Petrochemical Company

    Directory of Open Access Journals (Sweden)

    S. Farhang Dehghan

    2013-12-01

    .Conclusion: Based on the obtained results of investigating the noise level (objective exposure as well as the noise annoyance (subjective exposure at the studied company, it is necessary to adopt the management –technical noise reduction measures at manufacturing sectors as the personal noise exposure and environmental noise exposure and also noise personal exposure of administrative staff can be decreased.

  9. Modeling Of Construction Noise For Environmental Impact Assessment

    Directory of Open Access Journals (Sweden)

    Mohamed F. Hamoda

    2008-06-01

    Full Text Available This study measured the noise levels generated at different construction sites in reference to the stage of construction and the equipment used, and examined the methods to predict such noise in order to assess the environmental impact of noise. It included 33 construction sites in Kuwait and used artificial neural networks (ANNs for the prediction of noise. A back-propagation neural network (BPNN model was compared with a general regression neural network (GRNN model. The results obtained indicated that the mean equivalent noise level was 78.7 dBA which exceeds the threshold limit. The GRNN model was superior to the BPNN model in its accuracy of predicting construction noise due to its ability to train quickly on sparse data sets. Over 93% of the predictions were within 5% of the observed values. The mean absolute error between the predicted and observed data was only 2 dBA. The ANN modeling proved to be a useful technique for noise predictions required in the assessment of environmental impact of construction activities.

  10. Assessment of rural soundscapes with high-speed train noise.

    Science.gov (United States)

    Lee, Pyoung Jik; Hong, Joo Young; Jeon, Jin Yong

    2014-06-01

    In the present study, rural soundscapes with high-speed train noise were assessed through laboratory experiments. A total of ten sites with varying landscape metrics were chosen for audio-visual recording. The acoustical characteristics of the high-speed train noise were analyzed using various noise level indices. Landscape metrics such as the percentage of natural features (NF) and Shannon's diversity index (SHDI) were adopted to evaluate the landscape features of the ten sites. Laboratory experiments were then performed with 20 well-trained listeners to investigate the perception of high-speed train noise in rural areas. The experiments consisted of three parts: 1) visual-only condition, 2) audio-only condition, and 3) combined audio-visual condition. The results showed that subjects' preference for visual images was significantly related to NF, the number of land types, and the A-weighted equivalent sound pressure level (LAeq). In addition, the visual images significantly influenced the noise annoyance, and LAeq and NF were the dominant factors affecting the annoyance from high-speed train noise in the combined audio-visual condition. In addition, Zwicker's loudness (N) was highly correlated with the annoyance from high-speed train noise in both the audio-only and audio-visual conditions. © 2013.

  11. On the equivalence of Ising models on ‘small-world’ networks and LDPC codes on channels with memory

    International Nuclear Information System (INIS)

    Neri, Izaak; Skantzos, Nikos S

    2014-01-01

    We demonstrate the equivalence between thermodynamic observables of Ising spin-glass models on small-world lattices and the decoding properties of error-correcting low-density parity-check codes on channels with memory. In particular, the self-consistent equations for the effective field distributions in the spin-glass model within the replica symmetric ansatz are equivalent to the density evolution equations forr Gilbert–Elliott channels. This relationship allows us to present a belief-propagation decoding algorithm for finite-state Markov channels and to compute its performance at infinite block lengths from the density evolution equations. We show that loss of reliable communication corresponds to a first order phase transition from a ferromagnetic phase to a paramagnetic phase in the spin glass model. The critical noise levels derived for Gilbert–Elliott channels are in very good agreement with existing results in coding theory. Furthermore, we use our analysis to derive critical noise levels for channels with both memory and asymmetry in the noise. The resulting phase diagram shows that the combination of asymmetry and memory in the channel allows for high critical noise levels: in particular, we show that successful decoding is possible at any noise level of the bad channel when the good channel is good enough. Theoretical results at infinite block lengths using density evolution equations aree compared with average error probabilities calculated from a practical implementation of the corresponding decoding algorithms at finite block lengths. (paper)

  12. Test of the Equivalence Principle in an Einstein Elevator

    Science.gov (United States)

    Shapiro, Irwin I.; Glashow, S.; Lorenzini, E. C.; Cosmo, M. L.; Cheimets, P. N.; Finkelstein, N.; Schneps, M.

    2005-01-01

    This Annual Report illustrates the work carried out during the last grant-year activity on the Test of the Equivalence Principle in an Einstein Elevator. The activity focused on the following main topics: (1) analysis and conceptual design of a detector configuration suitable for the flight tests; (2) development of techniques for extracting a small signal from data strings with colored and white noise; (3) design of the mechanism that spins and releases the instrument package inside the cryostat; and (4) experimental activity carried out by our non-US partners (a summary is shown in this report). The analysis and conceptual design of the flight-detector (point 1) was focused on studying the response of the differential accelerometer during free fall, in the presence of errors and precession dynamics, for various detector's configurations. The goal was to devise a detector configuration in which an Equivalence Principle violation (EPV) signal at the sensitivity threshold level can be successfully measured and resolved out of a much stronger dynamics-related noise and gravity gradient. A detailed analysis and comprehensive simulation effort led us to a detector's design that can accomplish that goal successfully.

  13. Variability of road traffic noise recorded by stationary monitoring stations

    Science.gov (United States)

    Bąkowski, Andrzej; Radziszewski, Leszek

    2017-11-01

    The paper presents the analysis results of equivalent sound level recorded by two road traffic noise monitoring stations. The stations were located in Kielce (an example of a medium-size town in Poland) at the roads out of the town in the direction of Kraków and Warszawa. The measurements were carried out through stationary stations monitoring the noise and traffic of motor vehicles. The RMS values based on A-weighted sound level were recorded every 1 s in the buffer and the results were registered every 1 min over the period of investigations. The registered data were the basis for calculating the equivalent sound level for three time intervals: from 6:00 to 18:00, from 18:00 to 22:00 and from 22:00 to 6:00. Analysis included the values of the equivalent sound level recorded for different days of the week split into 24h periods, nights, days and evenings. The data analysed included recordings from 2013. The coefficient of variation and positional variation were proposed for performing comparative analysis of the obtained data scattering. The investigations indicated that the recorded data varied depending on the traffic routes. The differences concerned the values of coefficients of variation of the equivalent sound levels.

  14. A Mixed-Methods Trial of Broad Band Noise and Nature Sounds for Tinnitus Therapy: Group and Individual Responses Modeled under the Adaptation Level Theory of Tinnitus.

    Science.gov (United States)

    Durai, Mithila; Searchfield, Grant D

    2017-01-01

    Objectives: A randomized cross-over trial in 18 participants tested the hypothesis that nature sounds, with unpredictable temporal characteristics and high valence would yield greater improvement in tinnitus than constant, emotionally neutral broadband noise. Study Design: The primary outcome measure was the Tinnitus Functional Index (TFI). Secondary measures were: loudness and annoyance ratings, loudness level matches, minimum masking levels, positive and negative emotionality, attention reaction and discrimination time, anxiety, depression and stress. Each sound was administered using MP3 players with earbuds for 8 continuous weeks, with a 3 week wash-out period before crossing over to the other treatment sound. Measurements were undertaken for each arm at sound fitting, 4 and 8 weeks after administration. Qualitative interviews were conducted at each of these appointments. Results: From a baseline TFI score of 41.3, sound therapy resulted in TFI scores at 8 weeks of 35.6; broadband noise resulted in significantly greater reduction (8.2 points) after 8 weeks of sound therapy use than nature sounds (3.2 points). The positive effect of sound on tinnitus was supported by secondary outcome measures of tinnitus, emotion, attention, and psychological state, but not interviews. Tinnitus loudness level match was higher for BBN at 8 weeks; while there was little change in loudness level matches for nature sounds. There was no change in minimum masking levels following sound therapy administration. Self-reported preference for one sound over another did not correlate with changes in tinnitus. Conclusions: Modeled under an adaptation level theory framework of tinnitus perception, the results indicate that the introduction of broadband noise shifts internal adaptation level weighting away from the tinnitus signal, reducing tinnitus magnitude. Nature sounds may modify the affective components of tinnitus via a secondary, residual pathway, but this appears to be less important

  15. Equivalent Dynamic Models.

    Science.gov (United States)

    Molenaar, Peter C M

    2017-01-01

    Equivalences of two classes of dynamic models for weakly stationary multivariate time series are discussed: dynamic factor models and autoregressive models. It is shown that exploratory dynamic factor models can be rotated, yielding an infinite set of equivalent solutions for any observed series. It also is shown that dynamic factor models with lagged factor loadings are not equivalent to the currently popular state-space models, and that restriction of attention to the latter type of models may yield invalid results. The known equivalent vector autoregressive model types, standard and structural, are given a new interpretation in which they are conceived of as the extremes of an innovating type of hybrid vector autoregressive models. It is shown that consideration of hybrid models solves many problems, in particular with Granger causality testing.

  16. Noise Pollution

    Science.gov (United States)

    ... Regulated by EPA EPA or a designated Federal agency regulates noise sources, such as rail and motor carriers, low noise emission products, construction equipment, transport equipment, trucks, motorcycles, and the labeling of hearing ...

  17. Spatial variation in environmental noise and air pollution in New York City.

    Science.gov (United States)

    Kheirbek, Iyad; Ito, Kazuhiko; Neitzel, Richard; Kim, Jung; Johnson, Sarah; Ross, Zev; Eisl, Holger; Matte, Thomas

    2014-06-01

    Exposure to environmental noise from traffic is common in urban areas and has been linked to increased risks of adverse health effects including cardiovascular disease. Because traffic sources also produce air pollutants that increase the risk of cardiovascular morbidity, associations between traffic exposures and health outcomes may involve confounding and/or synergisms between air pollution and noise. While prior studies have characterized intraurban spatial variation in air pollution in New York City (NYC), limited data exists on the levels and spatial variation in noise levels. We measured 1-week equivalent continuous sound pressure levels (Leq) at 56 sites during the fall of 2012 across NYC locations with varying traffic intensity and building density that are routinely monitored for combustion-related air pollutants. We evaluated correlations among several noise metrics used to characterize noise exposures, including Leq during different time periods (night, day, weekday, weekend), Ldn (day-night noise), and measures of intermittent noise defined as the ratio of peak levels to median and background levels. We also examined correlations between sound pressure levels and co-located simultaneous measures of nitric oxide (NO), nitrogen dioxide (NO2), fine particulate matter (PM2.5), and black carbon (BC) as well as estimates of traffic and building density around the monitoring sites. Noise levels varied widely across the 56 monitoring sites; 1-week Leq varied by 21.6 dBA (range 59.1-80.7 dBA) with the highest levels observed during the weekday, daytime hours. Indices of average noise were well correlated with each other (r > 0.83), while indices of intermittent noise were not well correlated with average noise levels (r noise levels and traffic intensity within 100 m of the monitoring sites (r = 0.58). The high levels of noise observed in NYC often exceed recommended guidelines for outdoor and personal exposures, suggesting unhealthy levels in many locations

  18. Community noise

    Science.gov (United States)

    Bragdon, C. R.

    Airport and community land use planning as they relate to airport noise reduction are discussed. Legislation, community relations, and the physiological effect of airport noise are considered. Noise at the Logan, Los Angeles, and Minneapolis/St. Paul airports is discussed.

  19. Noise Pollution--What can be Done?

    Science.gov (United States)

    Shaw, Edgar A. G.

    1975-01-01

    Discusses the ratio of energy dissipated as sound to the mechanical output of devices. Considers noise levels, ranges vs. peaks, noise indexes, and health hazards. Indicates some problems vs. solutions in the technology of noise control. (GH)

  20. A Literature Survey of Noise Pollution.

    Science.gov (United States)

    Shih, H. H.

    Physically, noise is a complex sound that has little or no periodicity. However, the essential characteristic of noise is its undesirability. Thus, noise can be defined as any annoying or unwanted sound. In recent years, the rapid increase of noise level in our environment has become a national public health hazard. Noise affects man's state of…

  1. Determination of deep-level impurities and their effects on the small-single and LF noise properties of ion-implanted GaAs MESFETs

    International Nuclear Information System (INIS)

    Sriram, S.; Kim, B.; Ghosh, P.K.; Das, M.B.; Pennsylvania State Univ., University Park; Pennsylvania State Univ., University Park

    1982-01-01

    A large number of deep levels, with energies ranging from Esub(c)-0.19eV to Esub(c)-0.9eV, have been identified and characterized using ion-implanted MESFET's on undoped and Cr-doped LEC-grown semi-insulating GaAs substrates. Measurement techniques used include deep level transient (DLTS) and steady state spectroscopic (DLSS) methods. Large capture cross-section values are obtained for levels below Esub(c)-0.5eV, possibly due to high electric field. Spectral densities of LF noise with distinct bulges have been shown to be related to deep levels. In some samples, natural deep level related oscillations have been observed and their ionization energies have been determined. (author)

  2. Evaluation of noise pollution in oil extracting region of Lavan and the effect of noise enclosure on noise abatement

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2007-09-01

    Full Text Available Background and aims   Overexposure to industrial noise pollution induce hearing loss workers. Occupational hearing loss may cause interference whit oral communication, so it may  increase the risk of occupational accidents in workplace as well as affects whit social activities.  This study was conducted on Lavan Island, are of oil extracting regions in the south of Iran. The  object of this study was to evaluate noise pollution and determining the effect of noise enclosure  on noise abatement.   Methods   The noise sources were recognized and noise pressure level was measured by CEL- 440. Noise dose of the exposed workers in high level noise area were measured by CEL 272.   Results   Major noise sources were gas turbines, diesel generators, compressors, fans and gas containing pips, noise contour map revealers that noise level were higher than the recommended national exposure limit. The results of workers noise dose show that their noise exposure were  higher than the recommended value, (p<0.001. Finally, by using the results of noise frequency  analysis of different noise sources, the noise pressure level of each sources was determined in   terms of enclosing them.   Conclusion   By enclosing the noise sources, noise pressure levels can be lowered douse to  acceptable levels but limitation of applying enclosure should be regarded.  

  3. Electronic noise of superconducting tunnel junction detectors

    International Nuclear Information System (INIS)

    Jochum, J.; Kraus, H.; Gutsche, M.; Kemmather, B.; Feilitzsch, F. v.; Moessbauer, R.L.

    1994-01-01

    The optimal signal to noise ratio for detectors based on superconducting tunnel junctions is calculated and compared for the cases of a detector consisting of one single tunnel junction, as well as of series and of parallel connections of such tunnel junctions. The influence of 1 / f noise and its dependence on the dynamical resistance of tunnel junctions is discussed quantitatively. A single tunnel junction yields the minimum equivalent noise charge. Such a tunnel junction exhibits the best signal to noise ratio if the signal charge is independent of detector size. In case, signal charge increases with detector size, a parallel or a series connection of tunnel junctions would provide the optimum signal to noise ratio. The equivalent noise charge and the respective signal to noise ratio are deduced as functions of tunnel junction parameters such as tunneling time, quasiparticle lifetime, etc. (orig.)

  4. Noise from wind turbines

    International Nuclear Information System (INIS)

    Andersen, B.; Larsen, P.

    1993-01-01

    Denmark has 3200 wind turbines with an installed maximum capacity of 418MW. The most important Danish research projects into wind turbine noise and the main results are listed. These date from 1983. Two comprehensive studies are currently in progress. The first is an analytical and empirical investigation of aerodynamic noise from wind turbine rotors and has so far dealt mainly with tip noise. The measurement method, using a hard board mounted microphone on the ground near the turbine, is described. Four different tip designs have been tested. Some examples of reference sound power level spectra for three of the designs are presented. During the past two years a computerbased data acquisition system has been used for real-time determination of sound power levels. The second study, which has just commenced, is on annoyance from wind turbine noise. It will include noise measurements, masking calculations and a social survey on the perceived nuisance. (UK)

  5. FACTORS AFFECTING ROAD TRAFFIC NOISE ANNOYANCE AMONG WHITE-COLLAR EMPLOYEES WORKING IN TEHRAN

    Directory of Open Access Journals (Sweden)

    *1I. Alimohammadi, 2P. Nassiri, 3M. Azkhosh, 4M. Hoseini

    2010-01-01

    Full Text Available The effect of personal and attitudinal factors, noise level, hearing status and psychological traits on traffic-related noise annoyance among white-collar employees working in Tehran has been carefully analyzed. This survey has been conducted by interviewing 495 citizens working in non-manufacturing industries in Tehran, using questionnaires, Weinstein noise sensitivity scale, Beck’s depression, Buss and perry’s aggression, Zung’s anxiety, job satisfaction and Eysenc’s personality inventory. These citizens were office workers or store employees. Noise annoyance was determined both by numerical-based questionnaire criterion and by verbal index. Personal information, attitudinal factors and hearing conditions were determined using a general questionnaire. The amount of workplace noise the participants were exposed to was directly measured at their workplaces. It was revealed that among personal factors, age (p=0.030, marital status (p=0.004, residential period (p=0.001 and wealth (p=0.04 were related to noise annoyance. Attitudinal factors including sensitivity to noise (p=0.001, individual’s opinion on the need to control the noise (p=0.000 and individuals’ assessment of the amount of the workplace ambient noise (p= 0.000 were found to have relationship with noise annoyance. No meaningful relationship was seen between the equivalent noise level (p=0.879 and statistical noise level of L90 (p=0.909. The present study revealed that among all effective factors involved in noise annoyance, attitudinal factors had the most significant role in this regard.

  6. EQUIVALENCE VERSUS NON-EQUIVALENCE IN ECONOMIC TRANSLATION

    Directory of Open Access Journals (Sweden)

    Cristina, Chifane

    2012-01-01

    Full Text Available This paper aims at highlighting the fact that “equivalence” represents a concept worth revisiting and detailing upon when tackling the translation process of economic texts both from English into Romanian and from Romanian into English. Far from being exhaustive, our analysis will focus upon the problems arising from the lack of equivalence at the word level. Consequently, relevant examples from the economic field will be provided to account for the following types of non-equivalence at word level: culturespecific concepts; the source language concept is not lexicalised in the target language; the source language word is semantically complex; differences in physical and interpersonal perspective; differences in expressive meaning; differences in form; differences in frequency and purpose of using specific forms and the use of loan words in the source text. Likewise, we shall illustrate a number of translation strategies necessary to deal with the afore-mentioned cases of non-equivalence: translation by a more general word (superordinate; translation by a more neutral/less expressive word; translation by cultural substitution; translation using a loan word or loan word plus explanation; translation by paraphrase using a related word; translation by paraphrase using unrelated words; translation by omission and translation by illustration.

  7. Effects of road traffic background noise on judgments of individual airplane noises. Ph.D. Thesis

    Science.gov (United States)

    Powell, C. A.

    1979-01-01

    Two laboratory experiments were conducted to investigate the effects of road-traffic background noise on judgments of individual airplane flyover noises. In the first experiment, 27 subjects judged a set of 16 airplane flyover noises in the presence of traffic-noise sessions of 30-min duration consisting of the combinations of 3 traffic-noise types and 3 noise levels. In the second experiment, 24 subjects judged the same airplane flyover noises in the presence of traffic-noise sessions of 10-min duration consisting of the combinations of 2 traffic-noise types and 4 noise levels. In both experiments the airplane noises were judged less annoying in the presence of high traffic-noise levels than in the presence of low traffic-noise levels.

  8. Establishing Substantial Equivalence: Transcriptomics

    Science.gov (United States)

    Baudo, María Marcela; Powers, Stephen J.; Mitchell, Rowan A. C.; Shewry, Peter R.

    Regulatory authorities in Western Europe require transgenic crops to be substantially equivalent to conventionally bred forms if they are to be approved for commercial production. One way to establish substantial equivalence is to compare the transcript profiles of developing grain and other tissues of transgenic and conventionally bred lines, in order to identify any unintended effects of the transformation process. We present detailed protocols for transcriptomic comparisons of developing wheat grain and leaf material, and illustrate their use by reference to our own studies of lines transformed to express additional gluten protein genes controlled by their own endosperm-specific promoters. The results show that the transgenes present in these lines (which included those encoding marker genes) did not have any significant unpredicted effects on the expression of endogenous genes and that the transgenic plants were therefore substantially equivalent to the corresponding parental lines.

  9. Detecting Levels of Polyquaternium-10 (PQ-10) via Potentiometric Titration with Dextran Sulphate and Monitoring the Equivalence Point with a Polymeric Membrane-Based Polyion Sensor

    OpenAIRE

    Ferguson, Stephen A.; Wang, Xuewei; Meyerhoff, Mark E.

    2016-01-01

    Polymeric quaternary ammonium salts (polyquaterniums) have found increasing use in industrial and cosmetic applications in recent years. More specifically, polyquaternium-10 (PQ-10) is routinely used in cosmetic applications as a conditioner in personal care product formulations. Herein, we demonstrate the use of potentiometric polyion-sensitive polymeric membrane-based electrodes to quantify PQ-10 levels. Mixtures containing both PQ-10 and sodium lauryl sulfate (SLS) are used as model sample...

  10. Post commissioning noise study

    International Nuclear Information System (INIS)

    Heraud, P.

    2008-01-01

    This presentation described a wind farm post-commissioning study conducted at a wind farm owned by Helimax Energy Inc. The farm was located in a partly-forested, partly cultivated region in Quebec that featured gently rolling hills. Over 600 dwellings were located within 2 km of the wind farm, and 44 dwellings were within the wind farm's boundaries. The noise impact assessments were conducted at various points near the wind farm. The wind farm was designed using an International Standards Organization (ISO) noise propagation model and a 40 dBA to provide adequate setbacks. The study was conducted using 10 days of continuous measurements at selected points of a wind farm. Points of reception included points from 650 m to 800 m. Noise over 2 km was not thought to be contributed by the wind turbine. The nearest dwelling was 512 m from one of the farm's wind turbines. The study also considered ground factor, temperature, relative humidity, and the height of the receptors. Quebec noise level limits are 40 dBA at night, and 45 dBA during the day. Noise level limits are independent of wind speed. Measured noise contributions over 40 dBA were not observed during the measurement program. The wind turbines were only audible for 1 night out of the 30 night study period. It was concluded that the ISO noise propagation model is a reliable tool for conducting noise impact assessments. tabs., figs

  11. Assessment, analysis and appraisal of road traffic noise pollution in Rourkela city, India.

    Science.gov (United States)

    Goswami, Shreerup; Swain, Bijay Kumar; Panda, Santosh Kumar

    2013-09-01

    The problem of road traffic noise pollution has become a concern for both the public and the policy makers. Noise level was assessed in 12 different squares of Rourkela city during different specified times (7-10 a.m., 11 a.m.-2 p.m., 3-6 p.m., 7-10 p.m., 10 p.m.-12 midnight and 4-6 a.m.). Noise descriptors such as L,eq, traffic noise index, noise pollution level, noise climate, Lday, Levening, Lnight and Lden were assessed to reveal the extent of noise pollution due to heavy traffic in this city. The equivalent noise levels of all the 12 squares were found to be much beyond the permissible limit (70dB during day time and 55dB during night time). Appallingly, even the minimum L eq and NPL values were more than 82 dB and 96 dB during day time and 69 dB and 91 dB during night time respectively. Lden values of investigated squares ranged from 83.4 to 86.1 dB and were even more than the day time permissible limit of traffic noise. The prediction model was used in the present study to predict noise pollution level instead of Leq. Comparison of predicted with that of the actual measured data demonstrated that the model used for the prediction has the ability to calibrate the multicomponent traffic noise and yield reliable results close to that by direct measurement. Lastly, it is inferred that the dimension of the traffic generated noise pollution in Rourkela is critical.

  12. A Method to Estimate Students’ Exposure to Road Traffic Noise Events

    Directory of Open Access Journals (Sweden)

    Simone Secchi

    2018-03-01

    Full Text Available The correlation between exposure to traffic noise and students’ performance and annoyance has been investigated in literature mainly considering the relationship between indoor equivalent A-weighted sound pressure level (LAeq and students’ cognitive impairment. Annoyance is frequently related to the effect of short-duration noise events characterized by high sound pressure levels, such as those due to aircraft fly-over and pass-by of buses, heavy trucks, motorcycles, or street sweepers. These noise events are often described, over specific measurement periods, in terms of maximum A-weighted sound pressure level, LAmax, or statistical levels, such as LA1 or LA10. This aspect is not considered in the noise maps drawn in accordance with the European Environmental Noise Directive, as they provide the LAeq only, determined over day, evening, and night periods. In this paper, students’ exposure to road traffic noise is analyzed by means of regression equations obtained by the authors between LAeq and A-weighted maximum and statistical levels due to road traffic noise. The traffic noise of 28 urban streets was monitored during the opening period of Italian schools. A method is described to estimate students’ exposure to noise from data made available on noise maps by the municipalities of metropolitan areas. The application of this method to the case study of Florence shows that almost 60% of students from municipal primary and lower secondary schools could be exposed to the maximum sound pressure level (SPL inside the classroom greater than 55 dB(A every hour, probably exceeding the typical background noise in classrooms by more than 10 dB.

  13. The challenge of localizing vehicle backup alarms: Effects of passive and electronic hearing protectors, ambient noise level, and backup alarm spectral content

    Directory of Open Access Journals (Sweden)

    Khaled A Alali

    2011-01-01

    Full Text Available A human factors experiment employed a hemi-anechoic sound field in which listeners were required to localize a vehicular backup alarm warning signal (both a standard and a frequency-augmented alarm in 360-degrees azimuth in pink noise of 60 dBA and 90 dBA. Measures of localization performance included: (1 percentage correct localization, (2 percentage of right--left localization errors, (3 percentage of front-rear localization errors, and (4 localization absolute deviation in degrees from the alarm′s actual location. In summary, the data demonstrated that, with some exceptions, normal hearing listeners′ ability to localize the backup alarm in 360-degrees azimuth did not improve when wearing augmented hearing protectors (including dichotic sound transmission earmuffs, flat attenuation earplugs, and level-dependent earplugs as compared to when wearing conventional passive earmuffs or earplugs of the foam or flanged types. Exceptions were that in the 90 dBA pink noise, the flat attenuation earplug yielded significantly better accuracy than the polyurethane foam earplug and both the dichotic and the custom-made diotic electronic sound transmission earmuffs. However, the flat attenuation earplug showed no benefit over the standard pre-molded earplug, the arc earplug, and the passive earmuff. Confusions of front-rear alarm directions were most significant in the 90 dBA noise condition, wherein two types of triple-flanged earplugs exhibited significantly fewer front-rear confusions than either of the electronic muffs. On all measures, the diotic sound transmission earmuff resulted in the poorest localization of any of the protectors due to the fact that its single-microphone design did not enable interaural cues to be heard. Localization was consistently more degraded in the 90 dBA pink noise as compared with the relatively quiet condition of the 60 dBA pink noise. A frequency-augmented backup alarm, which incorporated 400 Hz and 4000 Hz components

  14. The principle of equivalence

    International Nuclear Information System (INIS)

    Unnikrishnan, C.S.

    1994-01-01

    Principle of equivalence was the fundamental guiding principle in the formulation of the general theory of relativity. What are its key elements? What are the empirical observations which establish it? What is its relevance to some new experiments? These questions are discussed in this article. (author). 11 refs., 5 figs

  15. Radioactive waste equivalence

    International Nuclear Information System (INIS)

    Orlowski, S.; Schaller, K.H.

    1990-01-01

    The report reviews, for the Member States of the European Community, possible situations in which an equivalence concept for radioactive waste may be used, analyses the various factors involved, and suggests guidelines for the implementation of such a concept. Only safety and technical aspects are covered. Other aspects such as commercial ones are excluded. Situations where the need for an equivalence concept has been identified are processes where impurities are added as a consequence of the treatment and conditioning process, the substitution of wastes from similar waste streams due to the treatment process, and exchange of waste belonging to different waste categories. The analysis of factors involved and possible ways for equivalence evaluation, taking into account in particular the chemical, physical and radiological characteristics of the waste package, and the potential risks of the waste form, shows that no simple all-encompassing equivalence formula may be derived. Consequently, a step-by-step approach is suggested, which avoids complex evaluations in the case of simple exchanges

  16. Equivalent Colorings with "Maple"

    Science.gov (United States)

    Cecil, David R.; Wang, Rongdong

    2005-01-01

    Many counting problems can be modeled as "colorings" and solved by considering symmetries and Polya's cycle index polynomial. This paper presents a "Maple 7" program link http://users.tamuk.edu/kfdrc00/ that, given Polya's cycle index polynomial, determines all possible associated colorings and their partitioning into equivalence classes. These…

  17. Correspondences. Equivalence relations

    International Nuclear Information System (INIS)

    Bouligand, G.M.

    1978-03-01

    We comment on sections paragraph 3 'Correspondences' and paragraph 6 'Equivalence Relations' in chapter II of 'Elements de mathematique' by N. Bourbaki in order to simplify their comprehension. Paragraph 3 exposes the ideas of a graph, correspondence and map or of function, and their composition laws. We draw attention to the following points: 1) Adopting the convention of writting from left to right, the composition law for two correspondences (A,F,B), (U,G,V) of graphs F, G is written in full generality (A,F,B)o(U,G,V) = (A,FoG,V). It is not therefore assumed that the co-domain B of the first correspondence is identical to the domain U of the second (EII.13 D.7), (1970). 2) The axiom of choice consists of creating the Hilbert terms from the only relations admitting a graph. 3) The statement of the existence theorem of a function h such that f = goh, where f and g are two given maps having the same domain (of definition), is completed if h is more precisely an injection. Paragraph 6 considers the generalisation of equality: First, by 'the equivalence relation associated with a map f of a set E identical to (x is a member of the set E and y is a member of the set E and x:f = y:f). Consequently, every relation R(x,y) which is equivalent to this is an equivalence relation in E (symmetrical, transitive, reflexive); then R admits a graph included in E x E, etc. Secondly, by means of the Hilbert term of a relation R submitted to the equivalence. In this last case, if R(x,y) is separately collectivizing in x and y, theta(x) is not the class of objects equivalent to x for R (EII.47.9), (1970). The interest of bringing together these two subjects, apart from this logical order, resides also in the fact that the theorem mentioned in 3) can be expressed by means of the equivalence relations associated with the functions f and g. The solutions of the examples proposed reveal their simplicity [fr

  18. NIVELES DE PRESIÓN SONORA EN EL SEGUNDO TRAMO DE TRANSCARIBE CARTAGENA 2007 NOISE PRESSURE LEVELS IN THE SECOND SECTION OF TRANSCARIBE CARTAGENA, 2007

    Directory of Open Access Journals (Sweden)

    Ildefonso Castro Angulo

    2007-07-01

    Full Text Available El proyecto de investigación para determinar los niveles de ruido en el segundo tramo de TransCaribe fue desarrollado entre los meses de mayo y junio de 2007, por el Grupo de Investigaciones Ambientales (GIA de la Fundación Universitaria Tecnológico Comfenalco. El desarrollo del sistema TransCaribe es una propuesta para mejorar la movilidad urbana en Cartagena mediante un sistema de transporte de gran envergadura que utilizará autobuses de alta ocupación con el fin último de mejorar la calidad de vida de los ciudadanos y la productividad de la ciudad. Este proyecto de transporte masivo espera reducir los niveles de emisión acústica. Esta investigación realizó un análisis acústico semanal que refleja el fenómeno de la contaminación sonora en Cartagena de Indias, específicamente en la zona adyacente a la avenida Pedro de Heredia, principal vía arteria de la ciudad. El estudio permite concluir que la zona donde será construido el segundo tramo de TransCaribe en ciertas horas del día no cumple normas de contaminación por ruido, pues sus niveles sobrepasan los límites definidos en la legislación (80 dB.This research project which intends to determine the levels of noise in the second section of Transcaribe was developed in May and June, 2007, by Tecnológico Comfenalco University Foundation Environmental Research Group (GIA. The development of Transcaribe system is a proposal to improve urban mobility in Cartagena by means of a high speed transportation system using high occupation buses with the aim of improving citizens' life quality and city productivity as well. This mass transportation system project hopes to reduce acoustic levels. Through this research a weekly acoustic analysis which reflects the phenomenon of noise pollution in Cartagena de Indias, especially in the zone closed to Pedro de Heredia Avenue, an important avenue in the city was carried out. The study allows concluding that the zone where the second section

  19. Spatial variability of noise level in agricultural machines Variabilidade espacial do nível de ruído em máquinas agrícolas

    OpenAIRE

    Tadayuki Yanagi Junior; Leonardo Schiassi; Diogo F. Rossoni; Patrícia F. Ponciano; Renato R. de Lima

    2012-01-01

    The knowledge of the spatial variability of noise levels and the build of kriging maps can help the evaluation of the salubrity of environments occupied by agricultural workers. Therefore, the objective of this research was to characterize the spatial variability of the noise level generated by four agricultural machines, using geostatistics, and to verify if the values are within the limits of human comfort. The evaluated machines were: harvester, chainsaw, brushcutter and tractor. The data ...

  20. Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: levels, toxic equivalents and relevance of non-dietary exposure.

    Science.gov (United States)

    Tue, Nguyen Minh; Katsura, Kana; Suzuki, Go; Tuyen, Le Huu; Takasuga, Takumi; Takahashi, Shin; Viet, Pham Hung; Tanabe, Shinsuke

    2014-08-01

    Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3-10 vs 1.7-4.8 and 0.60-5.7 pg CALUX-TEQ/g lipid, n=10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22-7.4 vs 1.1-3.0 pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13-15 vs 2.3-8.8 pg/g lipid) and PBDFs (1.1-1.5 vs <1.1 pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta-octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3-33 pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Work stress, worries, and pain interact synergistically with modelled traffic noise on cross-sectional associations with self-reported sleep problems

    OpenAIRE

    Kristiansen, Jesper; Persson, Roger; Björk, Jonas; Albin, Maria; Jakobsson, Kristina; Östergren, Per-Olof; Ardö, Jonas

    2011-01-01

    To examine the risk of sleep problems associated with work stress (job strain, job demands, and decision authority), worries and pain and to investigate the synergistic interaction between these factors and traffic noise. Sleep problems and predictor variables were assessed in a cross-sectional public health survey with 12,093 respondents. Traffic noise levels were assessed using modelled A-weighted energy equivalent traffic sound levels at the residence. The risk of sleep problems was modell...

  2. Analysis of specification of an electrode type sensor equivalent circuit on the base of impedance spectroscopy simulation

    International Nuclear Information System (INIS)

    Ogurtsov, V I; Mathewson, A; Sheehan, M M

    2005-01-01

    Simulation of electrochemical impedance spectroscopy (EIS) based on a LabVIEW model of a complex impedance measuring system in the frequency domain has been investigated to specify parameters of Randle's equivalent circuit, which is ordinarily used for electrode sensors. The model was based on a standard system for EIS instrumentation and consisted of a sensor modelled by Randle's equivalent circuit, a source of harmonic frequency sweep voltage applied to the sensor and a transimpedance amplifier, which transformed the sensor current to voltage. It provided impedance spectroscopy data for different levels of noise, modelled by current and voltage equivalent noise sources applied to the amplifier input. The noise influence on Randle's equivalent circuit specification was analysed by considering the behaviour of the approximation error. Different metrics including absolute, relative, semilogarithmic and logarithmic based distance between complex numbers on a complex plane were considered and compared to one another for evaluating this error. It was shown that the relative and logarithmic based metrics provide more reliable results for the determination of circuit parameters

  3. Analysis of specification of an electrode type sensor equivalent circuit on the base of impedance spectroscopy simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogurtsov, V I; Mathewson, A; Sheehan, M M [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland)

    2005-01-01

    Simulation of electrochemical impedance spectroscopy (EIS) based on a LabVIEW model of a complex impedance measuring system in the frequency domain has been investigated to specify parameters of Randle's equivalent circuit, which is ordinarily used for electrode sensors. The model was based on a standard system for EIS instrumentation and consisted of a sensor modelled by Randle's equivalent circuit, a source of harmonic frequency sweep voltage applied to the sensor and a transimpedance amplifier, which transformed the sensor current to voltage. It provided impedance spectroscopy data for different levels of noise, modelled by current and voltage equivalent noise sources applied to the amplifier input. The noise influence on Randle's equivalent circuit specification was analysed by considering the behaviour of the approximation error. Different metrics including absolute, relative, semilogarithmic and logarithmic based distance between complex numbers on a complex plane were considered and compared to one another for evaluating this error. It was shown that the relative and logarithmic based metrics provide more reliable results for the determination of circuit parameters.

  4. Surrogate Based Optimization of Aerodynamic Noise for Streamlined Shape of High Speed Trains

    Directory of Open Access Journals (Sweden)

    Zhenxu Sun

    2017-02-01

    Full Text Available Aerodynamic noise increases with the sixth power of the running speed. As the speed increases, aerodynamic noise becomes predominant and begins to be the main noise source at a certain high speed. As a result, aerodynamic noise has to be focused on when designing new high-speed trains. In order to perform the aerodynamic noise optimization, the equivalent continuous sound pressure level (SPL has been used in the present paper, which could take all of the far field observation probes into consideration. The Non-Linear Acoustics Solver (NLAS approach has been utilized for acoustic calculation. With the use of Kriging surrogate model, a multi-objective optimization of the streamlined shape of high-speed trains has been performed, which takes the noise level in the far field and the drag of the whole train as the objectives. To efficiently construct the Kriging model, the cross validation approach has been adopted. Optimization results reveal that both the equivalent continuous sound pressure level and the drag of the whole train are reduced in a certain extent.

  5. Experimental Evaluation of Equivalent-Fluid Models for Melamine Foam

    Science.gov (United States)

    Allen, Albert R.; Schiller, Noah H.

    2016-01-01

    Melamine foam is a soft porous material commonly used in noise control applications. Many models exist to represent porous materials at various levels of fidelity. This work focuses on rigid frame equivalent fluid models, which represent the foam as a fluid with a complex speed of sound and density. There are several empirical models available to determine these frequency dependent parameters based on an estimate of the material flow resistivity. Alternatively, these properties can be experimentally educed using an impedance tube setup. Since vibroacoustic models are generally sensitive to these properties, this paper assesses the accuracy of several empirical models relative to impedance tube measurements collected with melamine foam samples. Diffuse field sound absorption measurements collected using large test articles in a laboratory are also compared with absorption predictions determined using model-based and measured foam properties. Melamine foam slabs of various thicknesses are considered.

  6. The equivalence theorem

    International Nuclear Information System (INIS)

    Veltman, H.

    1990-01-01

    The equivalence theorem states that, at an energy E much larger than the vector-boson mass M, the leading order of the amplitude with longitudinally polarized vector bosons on mass shell is given by the amplitude in which these vector bosons are replaced by the corresponding Higgs ghosts. We prove the equivalence theorem and show its validity in every order in perturbation theory. We first derive the renormalized Ward identities by using the diagrammatic method. Only the Feynman-- 't Hooft gauge is discussed. The last step of the proof includes the power-counting method evaluated in the large-Higgs-boson-mass limit, needed to estimate the leading energy behavior of the amplitudes involved. We derive expressions for the amplitudes involving longitudinally polarized vector bosons for all orders in perturbation theory. The fermion mass has not been neglected and everything is evaluated in the region m f ∼M much-lt E much-lt m Higgs

  7. [Exposure of schoolchildren and teachers to noise at school].

    Science.gov (United States)

    Koszarny, Z; Goryński, P

    1990-01-01

    The factor of decisive influence on the acoustic climate in rooms is the inner noise, which is dependent in schools on the activity of children, overcrowding of classes and inadequate use of technical protective means. The inappropriate location of schools, although also important from the standpoint of acoustics, is a much lower source of noise than it is generally assumed. Particularly unfavourable acoustic conditions are in elementary schools with over 300 children in one shift. The spaces with the highest noise level include corridors, especially during recesses between lessons. The noise level in them is in the range of an equivalent sound A 60-95 dB, and the most frequent noise level is 80 dB. In a large part of schools the acoustic conditions in the corridors during recesses approach the critical values accepted for hearing protection in industrial plants, in some schools they are even exceeded. The situation is also unfavourable in other rooms such as doctor's office, director's room, reading rooms, rooms for teachers. These rooms are situated usually without taking into consideration of the acoustic conditions. This is particularly true of teachers' rooms which should give the teachers the possibility of resting before the next lesson. During lessons the noise level decreases in all rooms. However, the noisiest among them, corridors, classes situated near the hall for physical exercises and day-room, have still up to about 65 dB noise level. Generally speaking, in about 60% of rooms the acoustic conditions are below the recommended standard. The main cause, apart from overcrowding of schools, is low acoustic absorption ability of school rooms, and poor acoustic insulation ability of the doors in schools.

  8. Maximizing noise energy for noise-masking studies.

    Science.gov (United States)

    Jules Étienne, Cédric; Arleo, Angelo; Allard, Rémy

    2017-08-01

    Noise-masking experiments are widely used to investigate visual functions. To be useful, noise generally needs to be strong enough to noticeably impair performance, but under some conditions, noise does not impair performance even when its contrast approaches the maximal displayable limit of 100 %. To extend the usefulness of noise-masking paradigms over a wider range of conditions, the present study developed a noise with great masking strength. There are two typical ways of increasing masking strength without exceeding the limited contrast range: use binary noise instead of Gaussian noise or filter out frequencies that are not relevant to the task (i.e., which can be removed without affecting performance). The present study combined these two approaches to further increase masking strength. We show that binarizing the noise after the filtering process substantially increases the energy at frequencies within the pass-band of the filter given equated total contrast ranges. A validation experiment showed that similar performances were obtained using binarized-filtered noise and filtered noise (given equated noise energy at the frequencies within the pass-band) suggesting that the binarization operation, which substantially reduced the contrast range, had no significant impact on performance. We conclude that binarized-filtered noise (and more generally, truncated-filtered noise) can substantially increase the energy of the noise at frequencies within the pass-band. Thus, given a limited contrast range, binarized-filtered noise can display higher energy levels than Gaussian noise and thereby widen the range of conditions over which noise-masking paradigms can be useful.

  9. Development of computer program ENAUDIBL for computation of the sensation levels of multiple, complex, intrusive sounds in the presence of residual environmental masking noise

    Energy Technology Data Exchange (ETDEWEB)

    Liebich, R. E.; Chang, Y.-S.; Chun, K. C.

    2000-03-31

    The relative audibility of multiple sounds occurs in separate, independent channels (frequency bands) termed critical bands or equivalent rectangular (filter-response) bandwidths (ERBs) of frequency. The true nature of human hearing is a function of a complex combination of subjective factors, both auditory and nonauditory. Assessment of the probability of individual annoyance, community-complaint reaction levels, speech intelligibility, and the most cost-effective mitigation actions requires sensation-level data; these data are one of the most important auditory factors. However, sensation levels cannot be calculated by using single-number, A-weighted sound level values. This paper describes specific steps to compute sensation levels. A unique, newly developed procedure is used, which simplifies and improves the accuracy of such computations by the use of maximum sensation levels that occur, for each intrusive-sound spectrum, within each ERB. The newly developed program ENAUDIBL makes use of ERB sensation-level values generated with some computational subroutines developed for the formerly documented program SPECTRAN.

  10. Introductory guide to noise

    CSIR Research Space (South Africa)

    Ferreira, T.M

    1973-01-01

    Full Text Available or (by remaining at the 'alarm' level) prevents us from sleeping or resting. Some noise comes into buildings from outside, such as when a passing jet plane drowns a telephone conversation or when traffic noise prevents one from hearing an interesting... on aircraft that make too much noise. Motor cars, buses, buzz-bikes and vacuum deaners can be effectively quietened but until now the public has not been prepared to pay the price of legislation. Also, many young sports-car enthusiasts still think...

  11. Inhibitory noise

    Directory of Open Access Journals (Sweden)

    Alain Destexhe

    2010-03-01

    Full Text Available Cortical neurons in vivo may operate in high-conductance states, in which the major part of the neuron's input conductance is due to synaptic activity, sometimes several-fold larger than the resting conductance. We examine here the contribution of inhibition in such high-conductance states. At the level of the absolute conductance values, several studies have shown that cortical neurons in vivo are characterized by strong inhibitory conductances. However, conductances are balanced and spiking activity is mostly determined by fluctuations, but not much is known about excitatory and inhibitory contributions to these fluctuations. Models and dynamic-clamp experiments show that, during high-conductance states, spikes are mainly determined by fluctuations of inhibition, or by inhibitory noise. This stands in contrast to low-conductance states, in which excitatory conductances determine spiking activity. To determine these contributions from experimental data, maximum likelihood methods can be designed and applied to intracellular recordings in vivo. Such methods indicate that action potentials are indeed mostly correlated with inhibitory fluctuations in awake animals. These results argue for a determinant role for inhibitory fluctuations in evoking spikes, and do not support feed-forward modes of processing, for which opposite patterns are predicted.

  12. Equivalence, commensurability, value

    DEFF Research Database (Denmark)

    Albertsen, Niels

    2017-01-01

    Deriving value in Capital Marx uses three commensurability arguments (CA1-3). CA1 establishes equivalence in exchange as exchangeability with the same third commodity. CA2 establishes value as common denominator in commodities: embodied abstract labour. CA3 establishes value substance...... as commonality of labour: physiological labour. Tensions between these logics have permeated Marxist interpretations of value. Some have supported value as embodied labour (CA2, 3), others a monetary theory of value and value as ‘pure’ societal abstraction (ultimately CA1). They all are grounded in Marx....

  13. Occupational Noise Exposure among Toll Tellers at Toll Plaza in Malaysia

    Science.gov (United States)

    Azmi, Sharifah Nadya Syed; Dawal, Siti Zawiah Md; Ya, Tuan Mohammad Yusoff Shah Tuan; Saidin, Hamidi

    2010-10-01

    Toll tellers working at toll plaza have potential of exposure to high noise from the vehicles especially for the peak level of sound emitted by the heavy vehicles. However, occupational exposures in this workplace have not been adequately characterized and identified. Occupational noise exposure among toll tellers at toll plaza was assessed using Sound Level Meter, Noise Dosimeter and through questionnaire survey. These data were combined to estimate the work shift exposure level and health impacts to the toll tellers by using statistical analysis. Noise Dosimeter microphone was located at the hearing zone of the toll teller which working inside the toll booth and full-period measurements were collected for each work shift. The measurements were taken at 20 toll booths from 6.00 am to 2.00 pm for 5 days. 71 respondents participated in the survey to identify the symptoms of noise induced hearing loss and other health related problems among toll tellers. Results of this study indicated that occupational noise exposure among toll tellers for Mean Continuous Equivalent Level, Leq was 79.2±1.4 dB(A), Mean Maximum Level, Lmax was 107.8±3.6 dB(A) and Mean Peak Level, Lpeak was 136.6±9.9 dB. The Peak Level reported statistically significantly at 140 dB, the level of TLV recommended by ACGIH. The research findings indicated that the primary risk exposure to toll tellers comes from noise that emitted from heavy vehicles. Most of the toll tellers show symptoms of noise induced hearing loss and annoyed by the sources of noise at the toll plaza.

  14. Development of in-vehicle noise prediction models for Mumbai Metropolitan Region, India

    Directory of Open Access Journals (Sweden)

    Vishal Konbattulwar

    2016-08-01

    Full Text Available Traffic noise is one of the major sources of noise pollution in metropolitan regions causing various health hazards (e.g., long-term sleep disturbance, increase in blood pressure, physical tension, etc.. In this research, noise prediction models, which can measure the noise level experienced by the commuters while driving or traveling by motorized vehicles in the Mumbai Metropolitan Region, India, were developed. These models were developed by conducting a comprehensive study of various factors (e.g., vehicle speed, traffic volume and road characteristics, etc. affecting the levels of concentration of noise. A widespread data collection was done by conducting road trips of total length of 403.80 km via different modes of transport, such as air-conditioned (A/C car, non A/C car, bus and intermediate public transport (i.e., traditional 3-wheeler autos. Multiple regression analyses were performed to develop a functional relation between equivalent noise levels experienced by passengers while traveling (which was considered as a dependent variable and explanatory variables such as traffic characteristics, vehicle class, vehicle speed, various other location characteristics, etc. Noise levels are generally higher in the vicinity of intersections and signalized junctions. Independent data sets (for each mode of transport were used to validate the developed models. It was noted that maximum differences between observed and estimated values from the model were within the range of ±7.8% of the observed value.

  15. Does modern helicopter construction reduce noise exposure in helicopter rescue operations?

    Science.gov (United States)

    Küpper, Thomas; Jansing, Paul; Schöffl, Volker; van Der Giet, Simone

    2013-01-01

    During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknown. We estimated the noise exposure of the personnel for different helicopter types used during rescue operations in the Alps and in other regions of the world with special regard to the advanced types like Eurocopter EC 135 to compare the benefit of modern constructions for noise protection with earlier ones. The rescue operations over 1 year of four rescue bases in the Alps (Raron and Zermatt in Switzerland; Landeck and Innsbruck in Austria, n = 2731) were analyzed for duration of rescue operations (noise exposure). Noise levels were measured during rescue operations at defined points inside and outside the different aircraft. The setting is according to the European standard (Richtlinie 2003/10/EG Amtsblatt) and to Class 1 DIN/IEC 651. With both data sets the equivalent noise level L(eq8h) was calculated. For comparison it was assumed that all rescue operations were performed with a specific type of helicopter. Then model calculations for noise exposure by different helicopter types, such as Alouette IIIb, Alouette II 'Lama', Ecureuil AS350, Bell UH1D, Eurocopter EC135, and others were performed. Depending on modern technologies the situation for the personnel has been improved significantly. Nevertheless noise prevention, which includes noise intermissions in spare time, is essential. Medical checks of the crews by occupational medicine (e.g. 'G20' in Germany) are still mandatory.

  16. Experimental Research into Noise Emission of A Gear Micropump with Plastic Rotor

    Science.gov (United States)

    Rodionov, L. V.; Rekadze, P. D.

    2018-01-01

    The previous researches show that it’s possible to replace several parts of gear pump to plastic ones. This substitution leads to cost and noise reduction of the pump. Therefore, the series of acoustic experiments on a test bench were carry-out. Sound pressure levels were recorded with microphone, located in a pipe made of a vacuum rubber. Conducted experiment shows that acoustic characteristics of the micropump depend on the different material of driven rotor. Experimental result indicates that the proposed measures for replacing metal rotor to plastic one reduce micropump noise on the studied modes. The maximum achieved acoustic efficiency on equivalent level is 11 dB.

  17. Cryogenic test of the equivalence principle

    International Nuclear Information System (INIS)

    Worden, P.W. Jr.

    1976-01-01

    The weak equivalence principle is the hypothesis that the ratio of internal and passive gravitational mass is the same for all bodies. A greatly improved test of this principle is possible in an orbiting satellite. The most promising experiments for an orbital test are adaptations of the Galilean free-fall experiment and the Eotvos balance. Sensitivity to gravity gradient noise, both from the earth and from the spacecraft, defines a limit to the sensitivity in each case. This limit is generally much worse for an Eotvos balance than for a properly designed free-fall experiment. The difference is related to the difficulty of making a balance sufficiently isoinertial. Cryogenic technology is desirable to take full advantage of the potential sensitivity, but tides in the liquid helium refrigerant may produce a gravity gradient that seriously degrades the ultimate sensitivity. The Eotvos balance appears to have a limiting sensitivity to relative difference of rate of fall of about 2 x 10 -14 in orbit. The free-fall experiment is limited by helium tide to about 10 -15 ; if the tide can be controlled or eliminated the limit may approach 10 -18 . Other limitations to equivalence principle experiments are discussed. An experimental test of some of the concepts involved in the orbital free-fall experiment is continuing. The experiment consists in comparing the motions of test masses levitated in a superconducting magnetic bearing, and is itself a sensitive test of the equivalence principle. At present the levitation magnets, position monitors and control coils have been tested and major noise sources identified. A measurement of the equivalence principle is postponed pending development of a system for digitizing data. The experiment and preliminary results are described

  18. Occupational Noise Reduction in CNC Striping Process

    Science.gov (United States)

    Mahmad Khairai, Kamarulzaman; Shamime Salleh, Nurul; Razlan Yusoff, Ahmad

    2018-03-01

    Occupational noise hearing loss with high level exposure is common occupational hazards. In CNC striping process, employee that exposed to high noise level for a long time as 8-hour contributes to hearing loss, create physical and psychological stress that reduce productivity. In this paper, CNC stripping process with high level noises are measured and reduced to the permissible noise exposure. First condition is all machines shutting down and second condition when all CNC machine under operations. For both conditions, noise exposures were measured to evaluate the noise problems and sources. After improvement made, the noise exposures were measured to evaluate the effectiveness of reduction. The initial average noise level at the first condition is 95.797 dB (A). After the pneumatic system with leakage was solved, the noise reduced to 55.517 dB (A). The average noise level at the second condition is 109.340 dB (A). After six machines were gathered at one area and cover that area with plastic curtain, the noise reduced to 95.209 dB (A). In conclusion, the noise level exposure in CNC striping machine is high and exceed the permissible noise exposure can be reduced to acceptable levels. The reduction of noise level in CNC striping processes enhanced productivity in the industry.

  19. CRITERIA OF THE AVIATION NOISE ASSESSMENT FOR AERODROME ENVIRONS ZONING OF THE AIRPORTS AND PROTECTIVE MEASURES JUSTIFICATION

    Directory of Open Access Journals (Sweden)

    Oleg A. Kartyshev

    2017-01-01

    Full Text Available Problems in the sphere of an adverse ecological effect assessment of aerodrome environs aviation noise are analyzed. It is noted, that there is no modern standard and methodical base for such assessment. It is shown that when planning the build- ing, and also when developing noise-protective actions for residential areas in the zones of aviation noise increased level im- pact it’s most effectively to carry out acoustic zoning of areas near airports borders and flight routes. The system of transport sources noise rationing in Russia doesn't consider the established practice of its application. The aircraft of noisy types were actively taken out of service and aviation noise impact near the airports decreased, but the problem of noise protection, de- mands control when planning land use. Noise measurements in residential areas, near houses and inside, showed the excess of maximum allowed level values to 25-35 dBA (on equivalent value and to 25-40 dBA (on the maximum value.As a consequence of the European states policy in the sphere of aviation noise management and of aerodrome en- virons zoning noise levels at the airports of Europe and their surroundings were stabilized and the sizes of noise contours were reduced. For different countries there was made the analysis of legislative bases of the implementation of the re-striction requirement for residential areas and the possibility of using the territory under noise impact. For rationing theaerodrome environs noise of the airports it’s offered to take a sound equivalent level in which admissible values are ranged on three zones for the main standard criterion. The authors present acoustic measurements results in houses near the airport Vnukovo on condition of using standard two-chamber trimmable and folding windows with the ventilating valve. It is shown that the popular window designs can't provide inside noise reduction at night to the standard L Amax level = 45 dBA from the aviation source

  20. Establishing Substantial Equivalence: Proteomics

    Science.gov (United States)

    Lovegrove, Alison; Salt, Louise; Shewry, Peter R.

    Wheat is a major crop in world agriculture and is consumed after processing into a range of food products. It is therefore of great importance to determine the consequences (intended and unintended) of transgenesis in wheat and whether genetically modified lines are substantially equivalent to those produced by conventional plant breeding. Proteomic analysis is one of several approaches which can be used to address these questions. Two-dimensional PAGE (2D PAGE) remains the most widely available method for proteomic analysis, but is notoriously difficult to reproduce between laboratories. We therefore describe methods which have been developed as standard operating procedures in our laboratory to ensure the reproducibility of proteomic analyses of wheat using 2D PAGE analysis of grain proteins.

  1. Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-polychlorinated biphenyls in US meat and poultry, 2012-13: toxic equivalency levels, patterns, temporal trends and implications.

    Science.gov (United States)

    Lupton, Sara J; O'Keefe, Margaret; Muñiz-Ortiz, Jorge G; Clinch, Nelson; Basu, Pat

    2017-11-01

    The US Department of Agriculture (USDA) conducts a statistically based survey of the domestic meat supply (beef, pork, chicken and turkey) to determine current levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho-polychlorinated biphenyls (no-PCBs) every 5 years. Fat samples for each slaughter class were collected from US federally licensed slaughter facilities. The samples were processed and analysed for 17 PCDD/Fs and three no-PCBs. The sum of PCDD, PCDF and no-PCB toxic equivalencies (sum-TEQ) calculated using 2005 toxic-equivalency factors for all slaughter classes ranged from non-detect (n.d.) to 6.47 pg TEQ g -1 lipid. The median sum-TEQs, when n.d. = 0.5 LOD, for beef, pork, chicken and turkey were 0.66, 0.12, 0.13 and 0.34 pg TEQ g -1 lipid respectively. A comparison of the current survey with the previous three surveys shows a declining trend, with decreasing differences between medians; differences between the median sum-TEQs from 2007-08 and 2012-13 were -10%, -29%, -33% and -25% for beef, pork, chicken and turkey respectively. Several beef samples underwent further characterisation and congener patterns from these beef samples suggested pentachlorophenol treated wood as the likely exposure source. US consumer exposure to these compounds is relatively low and no slaughter class contributed more than 26% to the US Environmental Protection Agency (USEPA) chronic oral reference dose of 0.7 pg TEQ kg -1 bw day -1 .

  2. 34. Meeting of Experts. Noise immission

    International Nuclear Information System (INIS)

    2001-01-01

    In quiet areas there is a risk that wind turbine noise will exceed the background level even if it is lower than the immission limit. It will however be quite unpractical to take special notice to such areas and since the immission limit is respected the noise level will still be acceptable. Complaints from neighbours can unfortunately be expected no matter where the wind power plants are built. A small study in Denmark shows that about 10% of the population will feel disturbed by the immission limits that they have. Some of the participants pointed out that it would be simpler if wind power noise was included in other noise immission regulations. Within the European Union the Commission has made a proposal for common noise immission level descriptions and evaluation methods. It is primarily intended for traffic noise but can be expanded to include other areas, such as wind power noise. It suggests an equivalent annual average sound level (Lden) where the night level has a penalty of 10 dB(A) and the evening level of 5 dB(A). It should be emphasised that the proposal is not concerned with the specific values of the noise level limits, only with how they are defined. In some countries the limit varies with the time of the day. The night limit is the lowest and therefore the determining value in most cases. Wind turbines with variable RPM can however alter their speed to fit the limits and hence increase the energy output during the day and lower it at night. The result will be that a turbine with variable RPM can produce more energy than a similar one with fixed RPM but still fulfil the noise regulations. Though there are not many of these wind turbines installed today the number is likely to increase in the near future. As said when different day and night limits were discussed, having different immission limits at different hours will increase the possible energy output of a wind power plant with variable RPM. The new regulation in Holland uses a wind speed

  3. Underwater noise modelling for environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Farcas, Adrian [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom); Thompson, Paul M. [Lighthouse Field Station, Institute of Biological and Environmental Sciences, University of Aberdeen, Cromarty IV11 8YL (United Kingdom); Merchant, Nathan D., E-mail: nathan.merchant@cefas.co.uk [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom)

    2016-02-15

    Assessment of underwater noise is increasingly required by regulators of development projects in marine and freshwater habitats, and noise pollution can be a constraining factor in the consenting process. Noise levels arising from the proposed activity are modelled and the potential impact on species of interest within the affected area is then evaluated. Although there is considerable uncertainty in the relationship between noise levels and impacts on aquatic species, the science underlying noise modelling is well understood. Nevertheless, many environmental impact assessments (EIAs) do not reflect best practice, and stakeholders and decision makers in the EIA process are often unfamiliar with the concepts and terminology that are integral to interpreting noise exposure predictions. In this paper, we review the process of underwater noise modelling and explore the factors affecting predictions of noise exposure. Finally, we illustrate the consequences of errors and uncertainties in noise modelling, and discuss future research needs to reduce uncertainty in noise assessments.

  4. Underwater noise modelling for environmental impact assessment

    International Nuclear Information System (INIS)

    Farcas, Adrian; Thompson, Paul M.; Merchant, Nathan D.

    2016-01-01

    Assessment of underwater noise is increasingly required by regulators of development projects in marine and freshwater habitats, and noise pollution can be a constraining factor in the consenting process. Noise levels arising from the proposed activity are modelled and the potential impact on species of interest within the affected area is then evaluated. Although there is considerable uncertainty in the relationship between noise levels and impacts on aquatic species, the science underlying noise modelling is well understood. Nevertheless, many environmental impact assessments (EIAs) do not reflect best practice, and stakeholders and decision makers in the EIA process are often unfamiliar with the concepts and terminology that are integral to interpreting noise exposure predictions. In this paper, we review the process of underwater noise modelling and explore the factors affecting predictions of noise exposure. Finally, we illustrate the consequences of errors and uncertainties in noise modelling, and discuss future research needs to reduce uncertainty in noise assessments.

  5. Quantification of the equivalence principle

    International Nuclear Information System (INIS)

    Epstein, K.J.

    1978-01-01

    Quantitative relationships illustrate Einstein's equivalence principle, relating it to Newton's ''fictitious'' forces arising from the use of noninertial frames, and to the form of the relativistic time dilatation in local Lorentz frames. The equivalence principle can be interpreted as the equivalence of general covariance to local Lorentz covariance, in a manner which is characteristic of Riemannian and pseudo-Riemannian geometries

  6. Operational modeling of dose and noise for computed tomography in a pediatric hospital

    International Nuclear Information System (INIS)

    Miller Clemente, Rafael A.; Perez Diaz, Marlen; Mora Reyes, Yudel; Rodriguez Garlobo, Maikel; Castillo Salazar, Rafael

    2008-01-01

    Noise becomes a critical factor in Computed Tomography (CT) because most detailed applications on soft tissue show a low contrast nature. Noise establishes an inferior limit to the contrast detectable by the observer. Various pixel noise models had been devised taking into account operational parameters on Single and Multi Detector Slice CT. The aim of this work was to obtain a predictive operational model for image noise addressed to pediatric protocols, taking into account scanning factors with a Single Slice CT unit dedicated to pediatric applications. A multiple linear regression model is proposed to predict noise in images of uniform phantoms equivalent to head and abdomen. A model for reported volumetric Computed Tomography Dose Index (CTDI VOL ) was obtained too for tradeoffs analysis approaching optimization purposes in pediatric applications. Eight independent variables were considered: phantom diameter, reconstruction mode, tube current, tube kVp, collimation, Field of View (FOV), reconstruction filter, and post processing filter. Results show good agreement with measurements, with adjusted coefficients of multiple determination of 0.936 and 0.744 for noise and CTDI VOL models respectively. Tube current, object diameter, collimation and reconstruction filters were the most influencing variables. The model application contributes to identify each factor's influence enhancing the operational possibilities approaching optimization of noise and dose tradeoffs. Acceptable noise levels and optimization strategies can be devised from models obtained towards lower tube current values combined with greater slice thickness and kVp taking into account the doses to pediatric patients. (author)

  7. An investigation of the trade-off between the count level and image quality in myocardial perfusion SPECT using simulated images: the effects of statistical noise and object variability on defect detectability

    International Nuclear Information System (INIS)

    He Xin; Links, Jonathan M; Frey, Eric C

    2010-01-01

    Quantum noise as well as anatomic and uptake variability in patient populations limits observer performance on a defect detection task in myocardial perfusion SPECT (MPS). The goal of this study was to investigate the relative importance of these two effects by varying acquisition time, which determines the count level, and assessing the change in performance on a myocardial perfusion (MP) defect detection task using both mathematical and human observers. We generated ten sets of projections of a simulated patient population with count levels ranging from 1/128 to around 15 times a typical clinical count level to simulate different levels of quantum noise. For the simulated population we modeled variations in patient, heart and defect size, heart orientation and shape, defect location, organ uptake ratio, etc. The projection data were reconstructed using the OS-EM algorithm with no compensation or with attenuation, detector response and scatter compensation (ADS). The images were then post-filtered and reoriented to generate short-axis slices. A channelized Hotelling observer (CHO) was applied to the short-axis images, and the area under the receiver operating characteristics (ROC) curve (AUC) was computed. For each noise level and reconstruction method, we optimized the number of iterations and cutoff frequencies of the Butterworth filter to maximize the AUC. Using the images obtained with the optimal iteration and cutoff frequency and ADS compensation, we performed human observer studies for four count levels to validate the CHO results. Both CHO and human observer studies demonstrated that observer performance was dependent on the relative magnitude of the quantum noise and the patient variation. When the count level was high, the patient variation dominated, and the AUC increased very slowly with changes in the count level for the same level of anatomic variability. When the count level was low, however, quantum noise dominated, and changes in the count level

  8. Road traffic noise: self-reported noise annoyance versus GIS modelled road traffic noise exposure.

    Science.gov (United States)

    Birk, Matthias; Ivina, Olga; von Klot, Stephanie; Babisch, Wolfgang; Heinrich, Joachim

    2011-11-01

    self-reported road traffic noise annoyance is commonly used in epidemiological studies for assessment of potential health effects. Alternatively, some studies have used geographic information system (GIS) modelled exposure to road traffic noise as an objective parameter. The aim of this study was to analyse the association between noise exposure due to neighbouring road traffic and the noise annoyance of adults, taking other determinants into consideration. parents of 951 Munich children from the two German birth cohorts GINIplus and LISAplus reported their annoyance due to road traffic noise at home. GIS modelled road traffic noise exposure (L(den), maximum within a 50 m buffer) from the noise map of the city of Munich was available for all families. GIS-based calculated distance to the closest major road (≥10,000 vehicles per day) and questionnaire based-information about family income, parental education and the type of the street of residence were explored for their potential influence. An ordered logit regression model was applied. The noise levels (L(den)) and the reported noise annoyance were compared with an established exposure-response function. the correlation between noise annoyance and noise exposure (L(den)) was fair (Spearman correlation r(s) = 0.37). The distance to a major road and the type of street were strong predictors for the noise annoyance. The annoyance modelled by the established exposure-response function and that estimated by the ordered logit model were moderately associated (Pearson's correlation r(p) = 0.50). road traffic noise annoyance was associated with GIS modelled neighbouring road traffic noise exposure (L(den)). The distance to a major road and the type of street were additional explanatory factors of the noise annoyance appraisal.

  9. New recommendations for dose equivalent

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1985-01-01

    In its report 39, the International Commission on Radiation Units and Measurements (ICRU), has defined four new quantities for the determination of dose equivalents from external sources: the ambient dose equivalent, the directional dose equivalent, the individual dose equivalent, penetrating and the individual dose equivalent, superficial. The rationale behind these concepts and their practical application are discussed. Reference is made to numerical values of these quantities which will be the subject of a coming publication from the International Commission on Radiological Protection, ICRP. (Author)

  10. Comparison between old and new noise standards in Nagoya City

    Science.gov (United States)

    Asai, Atsushi; Mishina, Yoshiaki; Oishi, Yasaki; Ogura, Toshimitsu; Hayashi, Akinori; Omiya, Masaaki; Kuno, Kazuhiro

    2004-10-01

    The Japanese Environmental Agency (now the Ministry of the Environment) updated the environmental quality standards for noise in April 1999. The new standards replaced the median value of percentile level L50 for noise evaluation with the equivalent sound pressure level LAeq. The standards renewed the classification of areas and time sections. The most significant change was the introduction of category of artery-road-adjacent area. This report sets the range of the artery-road-adjacent area to 20 m or less from the applicable road to compare the new standards with the old, based on data collected in Nagoya City. The achieved rates for the new standards seem to be on the whole the same as those for the old standards. However, a detailed analysis reveals some differences, such as higher achieved rates in the artery-road-adjacent areas and lower achieved rates in the general areas for the new standards than for the old.

  11. System equivalent model mixing

    Science.gov (United States)

    Klaassen, Steven W. B.; van der Seijs, Maarten V.; de Klerk, Dennis

    2018-05-01

    This paper introduces SEMM: a method based on Frequency Based Substructuring (FBS) techniques that enables the construction of hybrid dynamic models. With System Equivalent Model Mixing (SEMM) frequency based models, either of numerical or experimental nature, can be mixed to form a hybrid model. This model follows the dynamic behaviour of a predefined weighted master model. A large variety of applications can be thought of, such as the DoF-space expansion of relatively small experimental models using numerical models, or the blending of different models in the frequency spectrum. SEMM is outlined, both mathematically and conceptually, based on a notation commonly used in FBS. A critical physical interpretation of the theory is provided next, along with a comparison to similar techniques; namely DoF expansion techniques. SEMM's concept is further illustrated by means of a numerical example. It will become apparent that the basic method of SEMM has some shortcomings which warrant a few extensions to the method. One of the main applications is tested in a practical case, performed on a validated benchmark structure; it will emphasize the practicality of the method.

  12. Uncorrelated Noise in Turbulence Measurements

    DEFF Research Database (Denmark)

    Kristensen, Leif; Lenschow, D. H.

    1985-01-01

    of atmospheric variability. The authors assume that the measured signal is a representation of a variable that is continuous on the scale of interest in the atmosphere. Uncorrelated noise affects the autovariance function (or, equivalently, the structure function) only between zero and the first lag, while its...... effect is smeared across the entire power spectrum. For this reason, quantities such as variance dissipation may be more conveniently estimated from the structure function than from the spectrum. The modeling results are confirmed by artificially modifying a test time series with Poisson noise...

  13. The Use of the Kurtosis-Adjusted Cumulative Noise Exposure Metric in Evaluating the Hearing Loss Risk for Complex Noise.

    Science.gov (United States)

    Xie, Hong-Wei; Qiu, Wei; Heyer, Nicholas J; Zhang, Mei-Bian; Zhang, Peng; Zhao, Yi-Ming; Hamernik, Roger P

    2016-01-01

    To test a kurtosis-adjusted cumulative noise exposure (CNE) metric for use in evaluating the risk of hearing loss among workers exposed to industrial noises. Specifically, to evaluate whether the kurtosis-adjusted CNE (1) provides a better association with observed industrial noise-induced hearing loss, and (2) provides a single metric applicable to both complex (non-Gaussian [non-G]) and continuous or steady state (Gaussian [G]) noise exposures for predicting noise-induced hearing loss (dose-response curves). Audiometric and noise exposure data were acquired on a population of screened workers (N = 341) from two steel manufacturing plants located in Zhejiang province and a textile manufacturing plant located in Henan province, China. All the subjects from the two steel manufacturing plants (N = 178) were exposed to complex noise, whereas the subjects from textile manufacturing plant (N = 163) were exposed to a G continuous noise. Each subject was given an otologic examination to determine their pure-tone HTL and had their personal 8-hr equivalent A-weighted noise exposure (LAeq) and full-shift noise kurtosis statistic (which is sensitive to the peaks and temporal characteristics of noise exposures) measured. For each subject, an unadjusted and kurtosis-adjusted CNE index for the years worked was created. Multiple linear regression analysis controlling for age was used to determine the relationship between CNE (unadjusted and kurtosis adjusted) and the mean HTL at 3, 4, and 6 kHz (HTL346) among the complex noise-exposed group. In addition, each subject's HTLs from 0.5 to 8.0 kHz were age and sex adjusted using Annex A (ISO-1999) to determine whether they had adjusted high-frequency noise-induced hearing loss (AHFNIHL), defined as an adjusted HTL shift of 30 dB or greater at 3.0, 4.0, or 6.0 kHz in either ear. Dose-response curves for AHFNIHL were developed separately for workers exposed to G and non-G noise using both unadjusted and adjusted CNE as the exposure

  14. Radiological equivalent of chemical pollutants

    International Nuclear Information System (INIS)

    Medina, V.O.

    1982-01-01

    The development of the peaceful uses of nuclear energy has caused continued effort toward public safety through radiation health protection measures and nuclear management practices. However, concern has not been focused on the development specifically in the operation of chemical pestrochemical industries as well as other industrial processes brought about by technological advancements. This article presents the comparison of the risk of radiation and chemicals. The methods used for comparing the risks of late effects of radiation and chemicals are considered at three levels. (a) as a frame of reference to give an impression of resolving power of biological tests; (b) as methods to quantify risks; (c) as instruments for an epidemiological survey of human populations. There are marked dissimilarities between chemicals and radiation and efforts to interpret chemical activity may not be achieved. Applicability of the concept of rad equivalence has many restrictions and as pointed out this approach is not an established one. (RTD)

  15. Land Use Regression Modeling of Outdoor Noise Exposure in Informal Settlements in Western Cape, South Africa.

    Science.gov (United States)

    Sieber, Chloé; Ragettli, Martina S; Brink, Mark; Toyib, Olaniyan; Baatjies, Roslyn; Saucy, Apolline; Probst-Hensch, Nicole; Dalvie, Mohamed Aqiel; Röösli, Martin

    2017-10-20

    In low- and middle-income countries, noise exposure and its negative health effects have been little explored. The present study aimed to assess the noise exposure situation in adults living in informal settings in the Western Cape Province, South Africa. We conducted continuous one-week outdoor noise measurements at 134 homes in four different areas. These data were used to develop a land use regression (LUR) model to predict A-weighted day-evening-night equivalent sound levels (L den ) from geographic information system (GIS) variables. Mean noise exposure during day (6:00-18:00) was 60.0 A-weighted decibels (dB(A)) (interquartile range 56.9-62.9 dB(A)), during night (22:00-6:00) 52.9 dB(A) (49.3-55.8 dB(A)) and average L den was 63.0 dB(A) (60.1-66.5 dB(A)). Main predictors of the LUR model were related to road traffic and household density. Model performance was low (adjusted R 2 = 0.130) suggesting that other influences than those represented in the geographic predictors are relevant for noise exposure. This is one of the few studies on the noise exposure situation in low- and middle-income countries. It demonstrates that noise exposure levels are high in these settings.

  16. Land Use Regression Modeling of Outdoor Noise Exposure in Informal Settlements in Western Cape, South Africa

    Science.gov (United States)

    Sieber, Chloé; Ragettli, Martina S.; Toyib, Olaniyan; Baatjies, Roslyn; Saucy, Apolline; Probst-Hensch, Nicole; Dalvie, Mohamed Aqiel; Röösli, Martin

    2017-01-01

    In low- and middle-income countries, noise exposure and its negative health effects have been little explored. The present study aimed to assess the noise exposure situation in adults living in informal settings in the Western Cape Province, South Africa. We conducted continuous one-week outdoor noise measurements at 134 homes in four different areas. These data were used to develop a land use regression (LUR) model to predict A-weighted day-evening-night equivalent sound levels (Lden) from geographic information system (GIS) variables. Mean noise exposure during day (6:00–18:00) was 60.0 A-weighted decibels (dB(A)) (interquartile range 56.9–62.9 dB(A)), during night (22:00–6:00) 52.9 dB(A) (49.3–55.8 dB(A)) and average Lden was 63.0 dB(A) (60.1–66.5 dB(A)). Main predictors of the LUR model were related to road traffic and household density. Model performance was low (adjusted R2 = 0.130) suggesting that other influences than those represented in the geographic predictors are relevant for noise exposure. This is one of the few studies on the noise exposure situation in low- and middle-income countries. It demonstrates that noise exposure levels are high in these settings. PMID:29053590

  17. Noise Induced Hearing Loss in Iran: (1997–2012): Systematic Review Article

    Science.gov (United States)

    SOLTANZADEH, Ahmad; EBRAHIMI, Hossein; FALLAHI, Majid; KAMALINIA, Mojtaba; GHASSEMI, Shadi; GOLMOHAMMADI, Rostam

    2014-01-01

    Noise-induced hearing loss, which is one of the 10 leading occupational diseases, is a debilitating and irreversible disease. During the recent 15-years period (1997–2012), several studies have investigated the association between noise, hearing damage and other side effects of noise in Iran. The aim of this study was to review systematically the relevant literature related to noise-induced hearing loss, lead to developing noise exposure limits. In this systematic review, two researchers independently extracted the data from 31 past studies that had considered noise-induced hearing loss (including hearing loss, temporary and permanent hearing threshold shift and auditory trauma). The data were then recorded in a modified form and Statistical analyses were performed using SPSS, version 16.0. In analyzed studies the weighted average equivalent sound pressure level [L Aeq ] was 90.29 dB(A) and average hearing loss was 26.44 dB(A). The Highest degree of hearing loss in the right ear was associated at 4000 Hz, and the highest degree of hearing loss in the left ear was associated to 1000 and 4000 Hz. The majority of the reviewed studies have confirmed that exposure to a noise level above 85 dB (A) can lead to an increased chance of hearing loss. Furthermore, the results of the present review indicated that as L Aeq increased up to 85 dB(A), so did the severity of the hearing loss. PMID:26171352

  18. Expanding the Interaction Equivalency Theorem

    Directory of Open Access Journals (Sweden)

    Brenda Cecilia Padilla Rodriguez

    2015-06-01

    Full Text Available Although interaction is recognised as a key element for learning, its incorporation in online courses can be challenging. The interaction equivalency theorem provides guidelines: Meaningful learning can be supported as long as one of three types of interactions (learner-content, learner-teacher and learner-learner is present at a high level. This study sought to apply this theorem to the corporate sector, and to expand it to include other indicators of course effectiveness: satisfaction, knowledge transfer, business results and return on expectations. A large Mexican organisation participated in this research, with 146 learners, 30 teachers and 3 academic assistants. Three versions of an online course were designed, each emphasising a different type of interaction. Data were collected through surveys, exams, observations, activity logs, think aloud protocols and sales records. All course versions yielded high levels of effectiveness, in terms of satisfaction, learning and return on expectations. Yet, course design did not dictate the types of interactions in which students engaged within the courses. Findings suggest that the interaction equivalency theorem can be reformulated as follows: In corporate settings, an online course can be effective in terms of satisfaction, learning, knowledge transfer, business results and return on expectations, as long as (a at least one of three types of interaction (learner-content, learner-teacher or learner-learner features prominently in the design of the course, and (b course delivery is consistent with the chosen type of interaction. Focusing on only one type of interaction carries a high risk of confusion, disengagement or missed learning opportunities, which can be managed by incorporating other forms of interactions.

  19. Adjusting phenotypes by noise control.

    Directory of Open Access Journals (Sweden)

    Kyung H Kim

    2012-01-01

    Full Text Available Genetically identical cells can show phenotypic variability. This is often caused by stochastic events that originate from randomness in biochemical processes involving in gene expression and other extrinsic cellular processes. From an engineering perspective, there have been efforts focused on theory and experiments to control noise levels by perturbing and replacing gene network components. However, systematic methods for noise control are lacking mainly due to the intractable mathematical structure of noise propagation through reaction networks. Here, we provide a numerical analysis method by quantifying the parametric sensitivity of noise characteristics at the level of the linear noise approximation. Our analysis is readily applicable to various types of noise control and to different types of system; for example, we can orthogonally control the mean and noise levels and can control system dynamics such as noisy oscillations. As an illustration we applied our method to HIV and yeast gene expression systems and metabolic networks. The oscillatory signal control was applied to p53 oscillations from DNA damage. Furthermore, we showed that the efficiency of orthogonal control can be enhanced by applying extrinsic noise and feedback. Our noise control analysis can be applied to any stochastic model belonging to continuous time Markovian systems such as biological and chemical reaction systems, and even computer and social networks. We anticipate the proposed analysis to be a useful tool for designing and controlling synthetic gene networks.

  20. Noise annoyance from wind turbines a review

    International Nuclear Information System (INIS)

    Pedersen, Eja

    2003-08-01

    This study summarises present knowledge on noise perception and annoyances from wind turbines in areas were people live or spend recreation time. There are two main types of noise from a wind turbine: mechanical noise and aerodynamic noise. The aerodynamic noise emits from the rotor blades passing the air. It has a swishing character with a modulation that makes it noticeable from the background noise. This part of the wind turbine noise was found to be the most annoying. Field studies performed among people living in the vicinity of wind turbines showed that there was a correlation between sound pressure level and noise annoyance, but annoyance was also influenced by visual factors such as the attitude to wind turbines' impact on the landscape. Noise annoyance was found at lower sound pressure levels than in studies of annoyance from traffic noise. There is no scientific evidence that noise at levels created by wind turbines could cause health problems other than annoyance. No studies on noise from wind turbines in wilderness areas have been found, but the reaction to other noise sources such as aircraft have been studied. In recreational areas, the expectation of quietness is high among visitors, but wind turbines are, in contrary to aircraft, stationary and could be avoided by recreationists. The visual impact of wind turbines might though be the dominant source of annoyance. Regulations on noise from wind turbines are based on different principles. Some states, e.g. Denmark, have a special legislation concerning wind turbines, while others, like Sweden, have used recommendations originally developed for a different noise source. The noise level could either be absolute, as in Germany, or related to the background noise level as in France. This background noise level could be standardised, measured or related to wind speed

  1. The equivalence principle

    International Nuclear Information System (INIS)

    Smorodinskij, Ya.A.

    1980-01-01

    The prerelativistic history of the equivalence principle (EP) is presented briefly. Its role in history of the general relativity theory (G.R.T.) discovery is elucidated. A modern idea states that the ratio of inert and gravitational masses does not differ from 1 at least up to the 12 sign after comma. Attention is paid to the difference of the gravitational field from electromagnetic one. The difference is as follows, the energy of the gravitational field distributed in space is the source of the field. These fields always interact at superposition. Electromagnetic fields from different sources are put together. On the basis of EP it is established the Sun field interact with the Earth gravitational energy in the same way as with any other one. The latter proves the existence of gravitation of the very gravitational field to a heavy body. A problem on gyroscope movement in the Earth gravitational field is presented as a paradox. The calculation has shown that gyroscope at satellite makes a positive precession, and its axis turns in an angle equal to α during a turn of the satellite round the Earth, but because of the space curvature - into the angle two times larger than α. A resulting turn is equal to 3α. It is shown on the EP basis that the polarization plane in any coordinate system does not turn when the ray of light passes in the gravitational field. Together with the historical value of EP noted is the necessity to take into account the requirements claimed by the EP at description of the physical world

  2. Assessment and analysis of noise pollution in Biskra public gardens (Algeria)

    Science.gov (United States)

    Bouzir, Tallal Abdel Karim; Zemmouri, Noureddine; Berkouk, Djihed

    2018-05-01

    A quantitative evaluation of noise pollution in the public gardens of Biskra, Algeria, was carried out in this research. The equivalent sound level (leq1min) was measured in 27 points distributed over the seven main gardens of the city. The results of the measurements show that the measured level of sound intensity varies from 56.38 dB in the Landon garden to 62.55 dB in the Larbi Ben Mhidi garden. By comparing, the measured values with the noise limit values recommended by the national legislation, the standards of the World Health Organization and the United States Environmental Protection Agency; it is clear that the sound environment in these public gardens do not comply with the recognized standards of acoustic comfort. The gardens' spaces are heavily over-exposed to traffic noise resulting in high levels acoustic pollution.

  3. Comparison of vibration and noise level on the boiler during operation of fuel heavy oil (mazut) and on natural gas in TO 'Istok' - Toplifikacija - Joint-Stock Co. for district heating Skopje (Macedonia)

    International Nuclear Information System (INIS)

    Kirovski, Hristo; Ninevski, Gjorgji; Sekovanikj, Ivica; Dzhingov, Gjorgji

    1999-01-01

    In the beginning of the heat season 1997/98, we started to use natural gas as a second fuel (the basic fuel is heavy fuel oil). Preparations were made for the use of natural gas in half of the TO 'Istok' Plant capacity (147 MW) in Skopje (Macedonia). During operation on natural gas, we noted that the levels of vibration and noise are higher when operating on heavy fuel oil. This was the reason why an investigation was carried out through a special company working on that issue. The investigation was made by measurement of vibration levels and noise at the boiler furnace in various orientation and levels. This material gives the results and conclusions from that investigation. A comparison has been made of the dynamic conditions and noise levels of the same boilers during operation on heavy fuel oil and on natural gas. We also compared the dynamic conditions and noise levels of different boilers during operations on natural gas, with different equipment for the atomizing of the natural gas. Conclusions on the dynamic conditions of the investigated boilers while operating on heavy fuel oil and on natural gas are given at the end of this material. (Author)

  4. Tracking of Nonstationary Noise Based on Data-Driven Recursive Noise Power Estimation

    NARCIS (Netherlands)

    Erkelens, J.S.; Heusdens, R.

    2008-01-01

    This paper considers estimation of the noise spectral variance from speech signals contaminated by highly nonstationary noise sources. The method can accurately track fast changes in noise power level (up to about 10 dB/s). In each time frame, for each frequency bin, the noise variance estimate is

  5. Aerodynamic Noise Generated by Shinkansen Cars

    Science.gov (United States)

    KITAGAWA, T.; NAGAKURA, K.

    2000-03-01

    The noise value (A -weighted sound pressure level, SLOW) generated by Shinkansen trains, now running at 220-300 km/h, should be less than 75 dB(A) at the trackside. Shinkansen noise, such as rolling noise, concrete support structure noise, and aerodynamic noise are generated by various parts of Shinkansen trains. Among these aerodynamic noise is important because it is the major contribution to the noise generated by the coaches running at high speed. In order to reduce the aerodynamic noise, a number of improvements to coaches have been made. As a result, the aerodynamic noise has been reduced, but it still remains significant. In addition, some aerodynamic noise generated from the lower parts of cars remains. In order to investigate the contributions of these noises, a method of analyzing Shinkansen noise has been developed and applied to the measured data of Shinkansen noise at speeds between 120 and 315 km/h. As a result, the following conclusions have been drawn: (1) Aerodynamic noise generated from the upper parts of cars was reduced considerably by smoothing car surfaces. (2) Aerodynamic noise generated from the lower parts of cars has a major influence upon the wayside noise.

  6. Preschool Personnel Exposure to Occupational Noise

    Directory of Open Access Journals (Sweden)

    Kaļužnaja Darja

    2016-10-01

    Full Text Available Increased noise, which is also below the occupational exposure values and is “hearing safe” noise, affects the exposed person’s health as a non-specific stressor. Increased noise level also creates an environment for additional vocal apparatus load. The objective of this study was to determine preschool personnel occupational noise and its relationship with subjective health complaints. Data were obtained with survey assistance through subjective answers of respondents about health complaints and noise exposure among Rīga preschool personnel. Objective noise measurements were made to assess real noise levels in the preschool environment. Data from 155 respondents and objective measurements of 37 preschool classrooms were obtained. The results showed that the average 8-h noise exposure among Rīga preschool educational institutions was 70 dB(A, which did not exceed the Latvian work environment noise limits, but exceeded the 35–40 dB(A noise limit in the educational environment guidelines recommended by the WHO. The survey results showed that loud noise is one of the most important workplace environmental factors (~70% of respondents feel a necessity to increase voice because of noise. A constant feeling of fatigue, headache, irritable feeling, and a desire to isolate oneself from others more often occurred in respondents exposed to increased noise, compared with those who noted that they were not exposed to increased noise. In general, loud noise was associated with increased subjective health complaints in preschool education institution personnel.

  7. Development and Validation of the Persian Version of the Acceptable Noise Level (ANL Test in Normal Children Aged 5-8 Years

    Directory of Open Access Journals (Sweden)

    Abdollah Moossavi

    2016-06-01

    Full Text Available Background: The goal of the present study was to develop and validate the Persian version of the Acceptable Noise Level (ANL test in normal, Persianspeaking children aged 5-8 years. Methods: This tool-making and non-experimental research was conducted in two stages. In the first stage the proper story was selected and recorded after evaluation of its content v