Task-Modulated Cortical Representations of Natural Sound Source Categories

DEFF Research Database (Denmark)

Hjortkjær, Jens; Kassuba, Tanja; Madsen, Kristoffer Hougaard

2018-01-01

In everyday sound environments, we recognize sound sources and events by attending to relevant aspects of an acoustic input. Evidence about the cortical mechanisms involved in extracting relevant category information from natural sounds is, however, limited to speech. Here, we used functional MRI...

Offshore dredger sounds: Source levels, sound maps, and risk assessment

NARCIS (Netherlands)

Jong, C.A.F. de; Ainslie, M.A.; Heinis, F.; Janmaat, J.

2016-01-01

The underwater sound produced during construction of the Port of Rotterdam harbor extension (Maasvlakte 2) was measured, with emphasis on the contribution of the trailing suction hopper dredgers during their various activities: dredging, transport, and discharge of sediment. Measured source levels

Orientation Estimation and Signal Reconstruction of a Directional Sound Source

DEFF Research Database (Denmark)

Guarato, Francesco

, one for each call emission, were compared to those calculated through a pre-existing technique based on interpolation of sound-pressure levels at microphone locations. The application of the method to the bat calls could provide knowledge on bat behaviour that may be useful for a bat-inspired sensor......Previous works in the literature about one tone or broadband sound sources mainly deal with algorithms and methods developed in order to localize the source and, occasionally, estimate the source bearing angle (with respect to a global reference frame). The problem setting assumes, in these cases......, omnidirectional receivers collecting the acoustic signal from the source: analysis of arrival times in the recordings together with microphone positions and source directivity cues allows to get information about source position and bearing. Moreover, sound sources have been included into sensor systems together...

Spatial resolution limits for the localization of noise sources using direct sound mapping

DEFF Research Database (Denmark)

Comesana, D. Fernandez; Holland, K. R.; Fernandez Grande, Efren

2016-01-01

the relationship between spatial resolution, noise level and geometry. The proposed expressions are validated via simulations and experiments. It is shown that particle velocity mapping yields better results for identifying closely spaced sound sources than sound pressure or sound intensity, especially...... extensively been used for many years to locate sound sources. However, it is not yet well defined when two sources should be regarded as resolved by means of direct sound mapping. This paper derives the limits of the direct representation of sound pressure, particle velocity and sound intensity by exploring......One of the main challenges arising from noise and vibration problems is how to identify the areas of a device, machine or structure that produce significant acoustic excitation, i.e. the localization of main noise sources. The direct visualization of sound, in particular sound intensity, has...

Offshore dredger sound: source levels, sound maps and risk assessment (abstract)

NARCIS (Netherlands)

Jong, C.A.F. de; Ainslie, M.A.; Heinis, F.; Janmaat, J.

2013-01-01

The Port of Rotterdam is expanding to meet the growing demand to accommodate large cargo vessels. One of the licensing conditions was the monitoring of the underwater sound produced during its construction, with an emphasis on the establishment of acoustic source levels of the Trailing Suction

Numerical design and testing of a sound source for secondary calibration of microphones using the Boundary Element Method

DEFF Research Database (Denmark)

Cutanda Henriquez, Vicente; Juhl, Peter Møller; Barrera Figueroa, Salvador

2009-01-01

Secondary calibration of microphones in free field is performed by placing the microphone under calibration in an anechoic chamber with a sound source, and exposing it to a controlled sound field. A calibrated microphone is also measured as a reference. While the two measurements are usually made...... apart to avoid acoustic interaction. As a part of the project Euromet-792, aiming to investigate and improve methods for secondary free-field calibration of microphones, a sound source suitable for simultaneous secondary free-field calibration has been designed using the Boundary Element Method...... of the Danish Fundamental Metrology Institute (DFM). The design and verification of the source are presented in this communication....

Movement and Perceptual Strategies to Intercept Virtual Sound Sources.

Directory of Open Access Journals (Sweden)

Naeem eKomeilipoor

2015-05-01

Full Text Available To intercept a moving object, one needs to be in the right place at the right time. In order to do this, it is necessary to pick up and use perceptual information that specifies the time to arrival of an object at an interception point. In the present study, we examined the ability to intercept a laterally moving virtual sound object by controlling the displacement of a sliding handle and tested whether and how the interaural time difference (ITD could be the main source of perceptual information for successfully intercepting the virtual object. The results revealed that in order to accomplish the task, one might need to vary the duration of the movement, control the hand velocity and time to reach the peak velocity (speed coupling, while the adjustment of movement initiation did not facilitate performance. Furthermore, the overall performance was more successful when subjects employed a time-to-contact (tau coupling strategy. This result shows that prospective information is available in sound for guiding goal-directed actions.

Active control of sound transmission through partitions composed of discretely controlled modules

Science.gov (United States)

Leishman, Timothy W.

, and error sensing, ASPs can achieve high sound transmission loss through efficient global control of transmitting surface vibrations. This approach is applicable to a wide variety of source and receiving spaces-and to both near fields and far fields.

A method for estimating the orientation of a directional sound source from source directivity and multi-microphone recordings: principles and application

DEFF Research Database (Denmark)

Guarato, Francesco; Jakobsen, Lasse; Vanderelst, Dieter

2011-01-01

Taking into account directivity of real sound sources makes it possible to try solving an interesting and biologically relevant problem: estimating the orientation in three-dimensional space of a directional sound source. The source, of known directivity, produces a broadband signal (in the ultra......Taking into account directivity of real sound sources makes it possible to try solving an interesting and biologically relevant problem: estimating the orientation in three-dimensional space of a directional sound source. The source, of known directivity, produces a broadband signal (in...

Separation of non-stationary multi-source sound field based on the interpolated time-domain equivalent source method

Science.gov (United States)

Bi, Chuan-Xing; Geng, Lin; Zhang, Xiao-Zheng

2016-05-01

In the sound field with multiple non-stationary sources, the measured pressure is the sum of the pressures generated by all sources, and thus cannot be used directly for studying the vibration and sound radiation characteristics of every source alone. This paper proposes a separation model based on the interpolated time-domain equivalent source method (ITDESM) to separate the pressure field belonging to every source from the non-stationary multi-source sound field. In the proposed method, ITDESM is first extended to establish the relationship between the mixed time-dependent pressure and all the equivalent sources distributed on every source with known location and geometry information, and all the equivalent source strengths at each time step are solved by an iterative solving process; then, the corresponding equivalent source strengths of one interested source are used to calculate the pressure field generated by that source alone. Numerical simulation of two baffled circular pistons demonstrates that the proposed method can be effective in separating the non-stationary pressure generated by every source alone in both time and space domains. An experiment with two speakers in a semi-anechoic chamber further evidences the effectiveness of the proposed method.

Reduction of interior sound fields in flexible cylinders by active vibration control

Science.gov (United States)

Jones, J. D.; Fuller, C. R.

1988-01-01

The mechanisms of interior sound reduction through active control of a thin flexible shell's vibrational response are presently evaluated in view of an analytical model. The noise source is a single exterior acoustic monopole. The active control model is evaluated for harmonic excitation; the results obtained indicate spatially-averaged noise reductions in excess of 20 dB over the source plane, for acoustic resonant conditions inside the cavity.

Reproduction of nearby sound sources using higher-order ambisonics with practical loudspeaker arrays

DEFF Research Database (Denmark)

Favrot, Sylvain Emmanuel; Buchholz, Jörg

2012-01-01

the impact of two existing and a new proposed regularization function on the reproduced sound fields and on the main auditory cue for nearby sound sources outside the median plane, i.e, low-frequencies interaural level differences (ILDs). The proposed regularization function led to a better reproduction......In order to reproduce nearby sound sources with distant loudspeakers to a single listener, the near field compensated (NFC) method for higher-order Ambisonics (HOA) has been previously proposed. In practical realization, this method requires the use of regularization functions. This study analyzes...... of point source sound fields compared to existing regularization functions for NFC-HOA. Measurements in realistic playback environments showed that, for very close sources, significant ILDs for frequencies above about 250 Hz can be reproduced with NFC-HOA and the proposed regularization function whereas...

Directional sound beam emission from a configurable compact multi-source system

KAUST Repository

Zhao, Jiajun; Jadhali, Rasha Al; Zhang, Likun; Wu, Ying

2018-01-01

We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation

Toward Inverse Control of Physics-Based Sound Synthesis

Science.gov (United States)

Pfalz, A.; Berdahl, E.

2017-05-01

Long Short-Term Memory networks (LSTMs) can be trained to realize inverse control of physics-based sound synthesizers. Physics-based sound synthesizers simulate the laws of physics to produce output sound according to input gesture signals. When a user's gestures are measured in real time, she or he can use them to control physics-based sound synthesizers, thereby creating simulated virtual instruments. An intriguing question is how to program a computer to learn to play such physics-based models. This work demonstrates that LSTMs can be trained to accomplish this inverse control task with four physics-based sound synthesizers.

Reconstruction of sound source signal by analytical passive TR in the environment with airflow

Science.gov (United States)

Wei, Long; Li, Min; Yang, Debin; Niu, Feng; Zeng, Wu

2017-03-01

In the acoustic design of air vehicles, the time-domain signals of noise sources on the surface of air vehicles can serve as data support to reveal the noise source generation mechanism, analyze acoustic fatigue, and take measures for noise insulation and reduction. To rapidly reconstruct the time-domain sound source signals in an environment with flow, a method combining the analytical passive time reversal mirror (AP-TR) with a shear flow correction is proposed. In this method, the negative influence of flow on sound wave propagation is suppressed by the shear flow correction, obtaining the corrected acoustic propagation time delay and path. Those corrected time delay and path together with the microphone array signals are then submitted to the AP-TR, reconstructing more accurate sound source signals in the environment with airflow. As an analytical method, AP-TR offers a supplementary way in 3D space to reconstruct the signal of sound source in the environment with airflow instead of the numerical TR. Experiments on the reconstruction of the sound source signals of a pair of loud speakers are conducted in an anechoic wind tunnel with subsonic airflow to validate the effectiveness and priorities of the proposed method. Moreover the comparison by theorem and experiment result between the AP-TR and the time-domain beamforming in reconstructing the sound source signal is also discussed.

Perceived loudness of spatially distributed sound sources

DEFF Research Database (Denmark)

Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

2005-01-01

psychoacoustic attributes into account. Therefore, a method for deriving loudness maps was developed in an earlier study [Song, Internoise2004, paper 271]. The present experiment investigates to which extent perceived loudness depends on the distribution of individual sound sources. Three loudspeakers were...... positioned 1.5 m from the centre of the listener’s head, one straight ahead, and two 10 degrees to the right and left, respectively. Six participants matched the loudness of either one, or two simultaneous sounds (narrow-band noises with 1-kHz, and 3.15-kHz centre frequencies) to a 2-kHz, 60-dB SPL narrow......-band noise placed in the frontal loudspeaker. The two sounds were either originating from the central speaker, or from the two offset loudspeakers. It turned out that the subjects perceived the noises to be softer when they were distributed in space. In addition, loudness was calculated from the recordings...

The Environmental Cost of Marine Sound Sources

NARCIS (Netherlands)

Ainslie, M.A.; Dekeling, R.P.A.

2011-01-01

Cumulative acoustic exposure is used as an indicator for the risk of negative impact to animals as a consequence of exposure to underwater sound. The free-field energy of a single source, defined as the total acoustic energy that would exist in the source’s free field, is shown to be closely related

Sound localization and occupational noise

Directory of Open Access Journals (Sweden)

Pedro de Lemos Menezes

2014-02-01

Full Text Available OBJECTIVE: The aim of this study was to determine the effects of occupational noise on sound localization in different spatial planes and frequencies among normal hearing firefighters. METHOD: A total of 29 adults with pure-tone hearing thresholds below 25 dB took part in the study. The participants were divided into a group of 19 firefighters exposed to occupational noise and a control group of 10 adults who were not exposed to such noise. All subjects were assigned a sound localization task involving 117 stimuli from 13 sound sources that were spatially distributed in horizontal, vertical, midsagittal and transverse planes. The three stimuli, which were square waves with fundamental frequencies of 500, 2,000 and 4,000 Hz, were presented at a sound level of 70 dB and were randomly repeated three times from each sound source. The angle between the speaker's axis in the same plane was 45°, and the distance to the subject was 1 m. RESULT: The results demonstrate that the sound localization ability of the firefighters was significantly lower (p<0.01 than that of the control group. CONCLUSION: Exposure to occupational noise, even when not resulting in hearing loss, may lead to a diminished ability to locate a sound source.

Forced sound transmission through a finite-sized single leaf panel subject to a point source excitation.

Science.gov (United States)

Wang, Chong

2018-03-01

In the case of a point source in front of a panel, the wavefront of the incident wave is spherical. This paper discusses spherical sound waves transmitting through a finite sized panel. The forced sound transmission performance that predominates in the frequency range below the coincidence frequency is the focus. Given the point source located along the centerline of the panel, forced sound transmission coefficient is derived through introducing the sound radiation impedance for spherical incident waves. It is found that in addition to the panel mass, forced sound transmission loss also depends on the distance from the source to the panel as determined by the radiation impedance. Unlike the case of plane incident waves, sound transmission performance of a finite sized panel does not necessarily converge to that of an infinite panel, especially when the source is away from the panel. For practical applications, the normal incidence sound transmission loss expression of plane incident waves can be used if the distance between the source and panel d and the panel surface area S satisfy d/S>0.5. When d/S ≈0.1, the diffuse field sound transmission loss expression may be a good approximation. An empirical expression for d/S=0  is also given.

Auralization of airborne sound insulation including the influence of source room

DEFF Research Database (Denmark)

Rindel, Jens Holger

2006-01-01

The paper describes a simple and acoustically accurate method for the auralization of airborne sound insulation between two rooms by means of a room acoustic simulation software (ODEON). The method makes use of a frequency independent transparency of the transmitting surface combined...... with a frequency dependent power setting of the source in the source room. The acoustic properties in terms of volume and reverberation time as well as the area of the transmitting surface are all included in the simulation. The user only has to select the position of the source in the source room and the receiver...... of the transmitting surface is used for the simulation of sound transmission. Also the reduced clarity of the auralization due to the reverberance of the source room is inherent in the method. Currently the method is restricted to transmission loss data in octave bands....

Modular and Adaptive Control of Sound Processing

Science.gov (United States)

van Nort, Douglas

This dissertation presents research into the creation of systems for the control of sound synthesis and processing. The focus differs from much of the work related to digital musical instrument design, which has rightly concentrated on the physicality of the instrument and interface: sensor design, choice of controller, feedback to performer and so on. Often times a particular choice of sound processing is made, and the resultant parameters from the physical interface are conditioned and mapped to the available sound parameters in an exploratory fashion. The main goal of the work presented here is to demonstrate the importance of the space that lies between physical interface design and the choice of sound manipulation algorithm, and to present a new framework for instrument design that strongly considers this essential part of the design process. In particular, this research takes the viewpoint that instrument designs should be considered in a musical control context, and that both control and sound dynamics must be considered in tandem. In order to achieve this holistic approach, the work presented in this dissertation assumes complementary points of view. Instrument design is first seen as a function of musical context, focusing on electroacoustic music and leading to a view on gesture that relates perceived musical intent to the dynamics of an instrumental system. The important design concept of mapping is then discussed from a theoretical and conceptual point of view, relating perceptual, systems and mathematically-oriented ways of examining the subject. This theoretical framework gives rise to a mapping design space, functional analysis of pertinent existing literature, implementations of mapping tools, instrumental control designs and several perceptual studies that explore the influence of mapping structure. Each of these reflect a high-level approach in which control structures are imposed on top of a high-dimensional space of control and sound synthesis

The effect of sound sources on soundscape appraisal

NARCIS (Netherlands)

van den Bosch, Kirsten; Andringa, Tjeerd

2014-01-01

In this paper we explore how the perception of sound sources (like traffic, birds, and the presence of distant people) influences the appraisal of soundscapes (as calm, lively, chaotic, or boring). We have used 60 one-minute recordings, selected from 21 days (502 hours) in March and July 2010.

Analysis, Design and Implementation of an Embedded Realtime Sound Source Localization System Based on Beamforming Theory

Directory of Open Access Journals (Sweden)

Arko Djajadi

2009-12-01

Full Text Available This project is intended to analyze, design and implement a realtime sound source localization system by using a mobile robot as the media. The implementated system uses 2 microphones as the sensors, Arduino Duemilanove microcontroller system with ATMega328p as the microprocessor, two permanent magnet DC motors as the actuators for the mobile robot and a servo motor as the actuator to rotate the webcam directing to the location of the sound source, and a laptop/PC as the simulation and display media. In order to achieve the objective of finding the position of a specific sound source, beamforming theory is applied to the system. Once the location of the sound source is detected and determined, the choice is either the mobile robot will adjust its position according to the direction of the sound source or only webcam will rotate in the direction of the incoming sound simulating the use of this system in a video conference. The integrated system has been tested and the results show the system could localize in realtime a sound source placed randomly on a half circle area (0 - 1800 with a radius of 0.3m - 3m, assuming the system is the center point of the circle. Due to low ADC and processor speed, achievable best angular resolution is still limited to 25o.

Active low frequency sound field control in a listening room using CABS (Controlled Acoustic Bass System) will also reduce the sound transmitted to neighbour rooms

DEFF Research Database (Denmark)

Nielsen, Sofus Birkedal; Celestinos, Adrian

2012-01-01

Sound in rooms and transmission of sound between rooms gives the biggest problems at low frequencies. Rooms with rectangular boundaries have strong resonance frequencies and will give big spatial variations in sound pressure level (SPL) in the source room, and an increase in SPL of 20 dB at a wall...... Bass System) is a time based room correction system for reproduced sound using loudspeakers. The system can remove room modes at low frequencies, by active cancelling the reflection from at the rear wall to a normal stereo setup. Measurements in a source room using CABS and in two neighbour rooms have...... shown a reduction in sound transmission of up to 10 dB at resonance frequencies and a reduction at broadband noise of 3 – 5 dB at frequencies up to 100 Hz. The ideas and understanding of the CABS system will also be given....

Wave field synthesis, adaptive wave field synthesis and ambisonics using decentralized transformed control: Potential applications to sound field reproduction and active noise control

Science.gov (United States)

Gauthier, Philippe-Aubert; Berry, Alain; Woszczyk, Wieslaw

2005-09-01

Sound field reproduction finds applications in listening to prerecorded music or in synthesizing virtual acoustics. The objective is to recreate a sound field in a listening environment. Wave field synthesis (WFS) is a known open-loop technology which assumes that the reproduction environment is anechoic. Classical WFS, therefore, does not perform well in a real reproduction space such as room. Previous work has suggested that it is physically possible to reproduce a progressive wave field in-room situation using active control approaches. In this paper, a formulation of adaptive wave field synthesis (AWFS) introduces practical possibilities for an adaptive sound field reproduction combining WFS and active control (with WFS departure penalization) with a limited number of error sensors. AWFS includes WFS and closed-loop ``Ambisonics'' as limiting cases. This leads to the modification of the multichannel filtered-reference least-mean-square (FXLMS) and the filtered-error LMS (FELMS) adaptive algorithms for AWFS. Decentralization of AWFS for sound field reproduction is introduced on the basis of sources' and sensors' radiation modes. Such decoupling may lead to decentralized control of source strength distributions and may reduce computational burden of the FXLMS and the FELMS algorithms used for AWFS. [Work funded by NSERC, NATEQ, Université de Sherbrooke and VRQ.] Ultrasound/Bioresponse to

Neural processing of auditory signals and modular neural control for sound tropism of walking machines

DEFF Research Database (Denmark)

Manoonpong, Poramate; Pasemann, Frank; Fischer, Joern

2005-01-01

and a neural preprocessing system together with a modular neural controller are used to generate a sound tropism of a four-legged walking machine. The neural preprocessing network is acting as a low-pass filter and it is followed by a network which discerns between signals coming from the left or the right....... The parameters of these networks are optimized by an evolutionary algorithm. In addition, a simple modular neural controller then generates the desired different walking patterns such that the machine walks straight, then turns towards a switched-on sound source, and then stops near to it....

Sound Control in the Physic Lab in the Polyacryl Company and Studying the Noise Reduction by Means of Different Absorbents

Directory of Open Access Journals (Sweden)

Harandi

1999-03-01

Full Text Available Studying noise effect at the workplace has more various aspects than other factors. So it is not surprising that its adverse impact on the physical and mental state of the society has been detected to some extent. There is a significant correlation between the hearing loss and the noise pollution of the workplaces. The most important ways to lessen and control the impact of noise are: substituting the noisy equipments with ones that produce less noise, correcting noise sources and isolating the sound source. In the current study we tried to control the noise level by using various sound absorbents and measured sound level by using these different substances. The results of these measurements have reported in the current article in details.

Control of Sound Transmission with Active-Passive Tiles

OpenAIRE

Goldstein, Andre L.

2006-01-01

Nowadays, numerous applications of active sound transmission control require lightweight partitions with high transmission loss over a broad frequency range and simple control strategies. In this work an active-passive sound transmission control approach is investigated that potentially addresses these requirements. The approach involves the use of lightweight stiff panels, or tiles, attached to a radiating base structure through active-passive soft mounts and covering the structure surface. ...

Potential-based methodology for active sound control in three dimensional settings

OpenAIRE

Lim, H.; Utyuzhnikov, S V; Lam, Y.W.; Kelly, L.

2014-01-01

This paper extends a potential-based approach to active noise shielding with preservation of wanted sound in three-dimensional settings. The approach, which was described in a previous publication [Lim et al., J. Acoust. Soc. Am. 129(2), 717–725 (2011)], provides several significant advantages over conventional noise control methods. Most significantly, the methodology does not require any information including the characterization of sources, impedance boundary conditions and surrounding med...

A wavenumber approach to analysing the active control of plane waves with arrays of secondary sources

Science.gov (United States)

Elliott, Stephen J.; Cheer, Jordan; Bhan, Lam; Shi, Chuang; Gan, Woon-Seng

2018-04-01

The active control of an incident sound field with an array of secondary sources is a fundamental problem in active control. In this paper the optimal performance of an infinite array of secondary sources in controlling a plane incident sound wave is first considered in free space. An analytic solution for normal incidence plane waves is presented, indicating a clear cut-off frequency for good performance, when the separation distance between the uniformly-spaced sources is equal to a wavelength. The extent of the near field pressure close to the source array is also quantified, since this determines the positions of the error microphones in a practical arrangement. The theory is also extended to oblique incident waves. This result is then compared with numerical simulations of controlling the sound power radiated through an open aperture in a rigid wall, subject to an incident plane wave, using an array of secondary sources in the aperture. In this case the diffraction through the aperture becomes important when its size is compatible with the acoustic wavelength, in which case only a few sources are necessary for good control. When the size of the aperture is large compared to the wavelength, and diffraction is less important but more secondary sources need to be used for good control, the results then become similar to those for the free field problem with an infinite source array.

Mount St. Helens: Controlled-source audio-frequency magnetotelluric (CSAMT) data and inversions

Science.gov (United States)

Wynn, Jeff; Pierce, Herbert A.

2015-01-01

This report describes a series of geoelectrical soundings carried out on and near Mount St. Helens volcano, Washington, in 2010–2011. These soundings used a controlled-source audio-frequency magnetotelluric (CSAMT) approach (Zonge and Hughes, 1991; Simpson and Bahr, 2005). We chose CSAMT for logistical reasons: It can be deployed by helicopter, has an effective depth of penetration of as much as 1 kilometer, and requires less wire than a Schlumberger sounding.

40 CFR 81.32 - Puget Sound Intrastate Air Quality Control Region.

Science.gov (United States)

2010-07-01

... Quality Control Regions § 81.32 Puget Sound Intrastate Air Quality Control Region. The Puget Sound Intrastate Air Quality Control Region (Washington) consists of the territorial area encompassed by the... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Puget Sound Intrastate Air Quality...

Differences in directional sound source behavior and perception between assorted computer room models

DEFF Research Database (Denmark)

Vigeant, Michelle C.; Wang, Lily M.; Rindel, Jens Holger

2004-01-01

considering reverberation time. However, for the three other parameters evaluated (sound pressure level, clarity index and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity......Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels...

Differences in directional sound source behavior and perception between assorted computer room models

DEFF Research Database (Denmark)

Vigeant, M. C.; Wang, L. M.; Rindel, Jens Holger

2004-01-01

time. However, for the three other parameters evaluated (sound-pressure level, clarity index, and lateral fraction), the changing diffusivity of the room does not diminish the importance of the directivity. The study therefore shows the importance of considering source directivity when using computer......Source directivity is an important input variable when using room acoustic computer modeling programs to generate auralizations. Previous research has shown that using a multichannel anechoic recording can produce a more natural sounding auralization, particularly as the number of channels...

Sound source location in cavitating tip vortices

International Nuclear Information System (INIS)

Higuchi, H.; Taghavi, R.; Arndt, R.E.A.

1985-01-01

Utilizing an array of three hydrophones, individual cavitation bursts in a tip vortex could be located. Theoretically, four hydrophones are necessary. Hence the data from three hydrophones are supplemented with photographic observation of the cavitating tip vortex. The cavitation sound sources are found to be localized to within one base chord length from the hydrofoil tip. This appears to correspond to the region of initial tip vortex roll-up. A more extensive study with a four sensor array is now in progress

The Reduction of Vertical Interchannel Crosstalk: The Analysis of Localisation Thresholds for Natural Sound Sources

Directory of Open Access Journals (Sweden)

Rory Wallis

2017-03-01

Full Text Available In subjective listening tests, natural sound sources were presented to subjects as vertically-oriented phantom images from two layers of loudspeakers, ‘height’ and ‘main’. Subjects were required to reduce the amplitude of the height layer until the position of the resultant sound source matched that of the same source presented from the main layer only (the localisation threshold. Delays of 0, 1 and 10 ms were applied to the height layer with respect to the main, with vertical stereophonic and quadraphonic conditions being tested. The results of the study showed that the localisation thresholds obtained were not significantly affected by sound source or presentation method. Instead, the only variable whose effect was significant was interchannel time difference (ICTD. For ICTD of 0 ms, the median threshold was −9.5 dB, which was significantly lower than the −7 dB found for both 1 and 10 ms. The results of the study have implications both for the recording of sound sources for three-dimensional (3D audio reproduction formats and also for the rendering of 3D images.

Improvements on the directional characteristics of a calibration sound source using the Boundary Element Method

DEFF Research Database (Denmark)

Henriquez, Vicente Cutanda; Barrera Figueroa, Salvador; Juhl, Peter Møller

2008-01-01

is of particular importance to achieve a sound field that reaches both microphones with the same level and that is sufficiently uniform at the microphone positions, in order to reduce the effect of misalignment. An existing sound source has been modeled using the Boundary Element Method, and the simulations have......The project Euromet-792 aims to investigate and improve methods for secondary free-field calibration of microphones. In this framework, the comparison method is being studied at DFM in relation to the more usual substitution method of microphone calibration. The design of the sound source...... been used to modify the source and make it suitable for this kind of calibration. It has been found that a central plug, already present in the device, can be re-shaped in such a way that makes the sound field on the microphone positions more uniform, even at rather high frequencies. Measurements have...

Sound Photographs to reveal vehicle pass-by sources with a calibrated source-strength level

NARCIS (Netherlands)

Mast, A.; Dool, T.C. van den; Toorn, J.D. van der; Watts, G.

2003-01-01

In national and European discussions, it appears that the conventional sound measurement techniques are insufficient to answer some relevant questions with respect to source strength of road vehicles. An example of such a question is: What is the importance of tyre-road noise on the one hand and

Active control of turbulent boundary layer-induced sound transmission through the cavity-backed double panels

Science.gov (United States)

Caiazzo, A.; Alujević, N.; Pluymers, B.; Desmet, W.

2018-05-01

This paper presents a theoretical study of active control of turbulent boundary layer (TBL) induced sound transmission through the cavity-backed double panels. The aerodynamic model used is based on the Corcos wall pressure distribution. The structural-acoustic model encompasses a source panel (skin panel), coupled through an acoustic cavity to the radiating panel (trim panel). The radiating panel is backed by a larger acoustic enclosure (the back cavity). A feedback control unit is located inside the acoustic cavity between the two panels. It consists of a control force actuator and a sensor mounted at the actuator footprint on the radiating panel. The control actuator can react off the source panel. It is driven by an amplified velocity signal measured by the sensor. A fully coupled analytical structural-acoustic model is developed to study the effects of the active control on the sound transmission into the back cavity. The stability and performance of the active control system are firstly studied on a reduced order model. In the reduced order model only two fundamental modes of the fully coupled system are assumed. Secondly, a full order model is considered with a number of modes large enough to yield accurate simulation results up to 1000 Hz. It is shown that convincing reductions of the TBL-induced vibrations of the radiating panel and the sound pressure inside the back cavity can be expected. The reductions are more pronounced for a certain class of systems, which is characterised by the fundamental natural frequency of the skin panel larger than the fundamental natural frequency of the trim panel.

Separation of radiated sound field components from waves scattered by a source under non-anechoic conditions

DEFF Research Database (Denmark)

Fernandez Grande, Efren; Jacobsen, Finn

2010-01-01

to the source. Thus the radiated free-field component is estimated simultaneously with solving the inverse problem of reconstructing the sound field near the source. The method is particularly suited to cases in which the overall contribution of reflected sound in the measurement plane is significant....

Sound reduction by metamaterial-based acoustic enclosure

Directory of Open Access Journals (Sweden)

Shanshan Yao

2014-12-01

Full Text Available In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

Sound reduction by metamaterial-based acoustic enclosure

Energy Technology Data Exchange (ETDEWEB)

Yao, Shanshan; Li, Pei; Zhou, Xiaoming; Hu, Gengkai, E-mail: hugeng@bit.edu.cn [Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education and School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081 (China)

2014-12-15

In many practical systems, acoustic radiation control on noise sources contained within a finite volume by an acoustic enclosure is of great importance, but difficult to be accomplished at low frequencies due to the enhanced acoustic-structure interaction. In this work, we propose to use acoustic metamaterials as the enclosure to efficiently reduce sound radiation at their negative-mass frequencies. Based on a circularly-shaped metamaterial model, sound radiation properties by either central or eccentric sources are analyzed by numerical simulations for structured metamaterials. The parametric analyses demonstrate that the barrier thickness, the cavity size, the source type, and the eccentricity of the source have a profound effect on the sound reduction. It is found that increasing the thickness of the metamaterial barrier is an efficient approach to achieve large sound reduction over the negative-mass frequencies. These results are helpful in designing highly efficient acoustic enclosures for blockage of sound in low frequencies.

Community Response to Multiple Sound Sources: Integrating Acoustic and Contextual Approaches in the Analysis

Directory of Open Access Journals (Sweden)

Peter Lercher

2017-06-01

Full Text Available Sufficient data refer to the relevant prevalence of sound exposure by mixed traffic sources in many nations. Furthermore, consideration of the potential effects of combined sound exposure is required in legal procedures such as environmental health impact assessments. Nevertheless, current practice still uses single exposure response functions. It is silently assumed that those standard exposure-response curves accommodate also for mixed exposures—although some evidence from experimental and field studies casts doubt on this practice. The ALPNAP-study population (N = 1641 shows sufficient subgroups with combinations of rail-highway, highway-main road and rail-highway-main road sound exposure. In this paper we apply a few suggested approaches of the literature to investigate exposure-response curves and its major determinants in the case of exposure to multiple traffic sources. Highly/moderate annoyance and full scale mean annoyance served as outcome. The results show several limitations of the current approaches. Even facing the inherent methodological limitations (energy equivalent summation of sound, rating of overall annoyance the consideration of main contextual factors jointly occurring with the sources (such as vibration, air pollution or coping activities and judgments of the wider area soundscape increases the variance explanation from up to 8% (bivariate, up to 15% (base adjustments up to 55% (full contextual model. The added predictors vary significantly, depending on the source combination. (e.g., significant vibration effects with main road/railway, not highway. Although no significant interactions were found, the observed additive effects are of public health importance. Especially in the case of a three source exposure situation the overall annoyance is already high at lower levels and the contribution of the acoustic indicators is small compared with the non-acoustic and contextual predictors. Noise mapping needs to go down to

Sound power emitted by a pure-tone source in a reverberation room

DEFF Research Database (Denmark)

Jacobsen, Finn; Molares, Alfonso Rodriguez

2009-01-01

Energy considerations are of enormous practical importance in acoustics. In "energy acoustics," sources of noise are described in terms of the sound power they emit, the underlying assumption being that this property is independent of the particular environment where the sources are placed. Howev...

Low frequency sound field control for loudspeakers in rectangular rooms using CABS (Controlled Acoustical Bass System)

DEFF Research Database (Denmark)

Nielsen, Sofus Birkedal; Celestinos, Adrian

2010-01-01

Rectangular rooms are the most common shape for sound reproduction, but at low frequencies the reflections from the boundaries of the room cause large spatial variations in the sound pressure level.  Variations up to 30 dB are normal, not only at the room modes, but basically at all frequencies....... As sound propagates in time, it seems natural that the problems can best be analyzed and solved in the time domain. A time based room correction system named CABS (Controlled Acoustical Bass System) has been developed for sound reproduction in rectangular listening rooms. It can control the sound...... sound field in the whole room, and short impulse response.  In a standard listening room (180 m3) only 4 loudspeakers are needed, 2 more than a traditional stereo setup. CABS is controlled by a developed DSP system. The time based approached might help with the understanding of sound field control...

Detection of aeroacoustic sound sources on aircraft and wind turbines

NARCIS (Netherlands)

Oerlemans, Stefan

2009-01-01

This thesis deals with the detection of aeroacoustic sound sources on aircraft and wind turbines using phased microphone arrays. First, the reliability of the array technique is assessed using airframe noise measurements in open and closed wind tunnels. It is demonstrated that quantitative acoustic

The low-frequency sound power measuring technique for an underwater source in a non-anechoic tank

Science.gov (United States)

Zhang, Yi-Ming; Tang, Rui; Li, Qi; Shang, Da-Jing

2018-03-01

In order to determine the radiated sound power of an underwater source below the Schroeder cut-off frequency in a non-anechoic tank, a low-frequency extension measuring technique is proposed. This technique is based on a unique relationship between the transmission characteristics of the enclosed field and those of the free field, which can be obtained as a correction term based on previous measurements of a known simple source. The radiated sound power of an unknown underwater source in the free field can thereby be obtained accurately from measurements in a non-anechoic tank. To verify the validity of the proposed technique, a mathematical model of the enclosed field is established using normal-mode theory, and the relationship between the transmission characteristics of the enclosed and free fields is obtained. The radiated sound power of an underwater transducer source is tested in a glass tank using the proposed low-frequency extension measuring technique. Compared with the free field, the radiated sound power level of the narrowband spectrum deviation is found to be less than 3 dB, and the 1/3 octave spectrum deviation is found to be less than 1 dB. The proposed testing technique can be used not only to extend the low-frequency applications of non-anechoic tanks, but also for measurement of radiated sound power from complicated sources in non-anechoic tanks.

A novel method for direct localized sound speed measurement using the virtual source paradigm

DEFF Research Database (Denmark)

Byram, Brett; Trahey, Gregg E.; Jensen, Jørgen Arendt

2007-01-01

) mediums. The inhomogeneous mediums were arranged as an oil layer, one 6 mm thick and the other 11 mm thick, on top of a water layer. To complement the phantom studies, sources of error for spatial registration of virtual detectors were simulated. The sources of error presented here are multiple sound...... registered virtual detector. Between a pair of registered virtual detectors a spherical wave is propagated. By beamforming the received data the time of flight between the two virtual sources can be calculated. From this information the local sound speed can be estimated. Validation of the estimator used...... both phantom and simulation results. The phantom consisted of two wire targets located near the transducer's axis at depths of 17 and 28 mm. Using this phantom the sound speed between the wires was measured for a homogeneous (water) medium and for two inhomogeneous (DB-grade castor oil and water...

The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl.

Science.gov (United States)

Baxter, Caitlin S; Nelson, Brian S; Takahashi, Terry T

2013-02-01

Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls (Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643-655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

Perceptual assessment of quality of urban soundscapes with combined noise sources and water sounds.

Science.gov (United States)

Jeon, Jin Yong; Lee, Pyoung Jik; You, Jin; Kang, Jian

2010-03-01

In this study, urban soundscapes containing combined noise sources were evaluated through field surveys and laboratory experiments. The effect of water sounds on masking urban noises was then examined in order to enhance the soundscape perception. Field surveys in 16 urban spaces were conducted through soundwalking to evaluate the annoyance of combined noise sources. Synthesis curves were derived for the relationships between noise levels and the percentage of highly annoyed (%HA) and the percentage of annoyed (%A) for the combined noise sources. Qualitative analysis was also made using semantic scales for evaluating the quality of the soundscape, and it was shown that the perception of acoustic comfort and loudness was strongly related to the annoyance. A laboratory auditory experiment was then conducted in order to quantify the total annoyance caused by road traffic noise and four types of construction noise. It was shown that the annoyance ratings were related to the types of construction noise in combination with road traffic noise and the level of the road traffic noise. Finally, water sounds were determined to be the best sounds to use for enhancing the urban soundscape. The level of the water sounds should be similar to or not less than 3 dB below the level of the urban noises.

Aerofoil broadband and tonal noise modelling using stochastic sound sources and incorporated large scale fluctuations

Science.gov (United States)

Proskurov, S.; Darbyshire, O. R.; Karabasov, S. A.

2017-12-01

The present work discusses modifications to the stochastic Fast Random Particle Mesh (FRPM) method featuring both tonal and broadband noise sources. The technique relies on the combination of incorporated vortex-shedding resolved flow available from Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation with the fine-scale turbulence FRPM solution generated via the stochastic velocity fluctuations in the context of vortex sound theory. In contrast to the existing literature, our method encompasses a unified treatment for broadband and tonal acoustic noise sources at the source level, thus, accounting for linear source interference as well as possible non-linear source interaction effects. When sound sources are determined, for the sound propagation, Acoustic Perturbation Equations (APE-4) are solved in the time-domain. Results of the method's application for two aerofoil benchmark cases, with both sharp and blunt trailing edges are presented. In each case, the importance of individual linear and non-linear noise sources was investigated. Several new key features related to the unsteady implementation of the method were tested and brought into the equation. Encouraging results have been obtained for benchmark test cases using the new technique which is believed to be potentially applicable to other airframe noise problems where both tonal and broadband parts are important.

Evolutionary Sound Synthesis Controlled by Gestural Data

Directory of Open Access Journals (Sweden)

Jose Fornari

2011-05-01

Full Text Available This article focuses on the interdisciplinary research involving Computer Music and Generative Visual Art. We describe the implementation of two interactive artistic systems based on principles of Gestural Data (WILSON, 2002 retrieval and self-organization (MORONI, 2003, to control an Evolutionary Sound Synthesis method (ESSynth. The first implementation uses, as gestural data, image mapping of handmade drawings. The second one uses gestural data from dynamic body movements of dance. The resulting computer output is generated by an interactive system implemented in Pure Data (PD. This system uses principles of Evolutionary Computation (EC, which yields the generation of a synthetic adaptive population of sound objects. Considering that music could be seen as “organized sound” the contribution of our study is to develop a system that aims to generate "self-organized sound" – a method that uses evolutionary computation to bridge between gesture, sound and music.

Maximum likelihood approach to “informed” Sound Source Localization for Hearing Aid applications

DEFF Research Database (Denmark)

Farmani, Mojtaba; Pedersen, Michael Syskind; Tan, Zheng-Hua

2015-01-01

Most state-of-the-art Sound Source Localization (SSL) algorithms have been proposed for applications which are "uninformed'' about the target sound content; however, utilizing a wireless microphone worn by a target talker, enables recent Hearing Aid Systems (HASs) to access to an almost noise......-free sound signal of the target talker at the HAS via the wireless connection. Therefore, in this paper, we propose a maximum likelihood (ML) approach, which we call MLSSL, to estimate the Direction of Arrival (DoA) of the target signal given access to the target signal content. Compared with other "informed...

Detection of aeroacoustic sound sources on aircraft and wind turbines

International Nuclear Information System (INIS)

Oerlemans, S.

2009-01-01

This thesis deals with the detection of aeroacoustic sound sources on aircraft and wind turbines using phased microphone arrays. First, the reliability of the array technique is assessed using airframe noise measurements in open and closed wind tunnels. It is demonstrated that quantitative acoustic measurements are possible in both wind tunnels. Then, the array technique is applied to characterize the noise sources on two modern large wind turbines. It is shown that practically all noise emitted to the ground is produced by the outer part of the blades during their downward movement. This asymmetric source pattern, which causes the typical swishing noise during the passage of the blades, can be explained by trailing edge noise directivity and convective amplification. Next, a semi-empirical prediction method is developed for the noise from large wind turbines. The prediction code is successfully validated against the experimental results, not only with regard to sound levels, spectra, and directivity, but also with regard to the noise source distribution in the rotor plane and the temporal variation in sound level (swish). The validated prediction method is then applied to calculate wind turbine noise footprints, which show that large swish amplitudes can occur even at large distance. The influence of airfoil shape on blade noise is investigated through acoustic wind tunnel tests on a series of wind turbine airfoils. Measurements are carried out at various wind speeds and angles of attack, with and without upstream turbulence and boundary layer tripping. The speed dependence, directivity, and tonal behaviour are determined for both trailing edge noise and inflow turbulence noise. Finally, two noise reduction concepts are tested on a large wind turbine: acoustically optimized airfoils and trailing edge serrations. Both blade modifications yield a significant trailing edge noise reduction at low frequencies, but also cause increased tip noise at high frequencies

The influence of signal parameters on the sound source localization ability of a harbor porpoise (Phocoena phocoena)

NARCIS (Netherlands)

Kastelein, R.A.; Haan, D.de; Verboom, W.C.

2007-01-01

It is unclear how well harbor porpoises can locate sound sources, and thus can locate acoustic alarms on gillnets. Therefore the ability of a porpoise to determine the location of a sound source was determined. The animal was trained to indicate the active one of 16 transducers in a 16-m -diam

Towards a Synesthesia Laboratory: Real-time Localization and Visualization of a Sound Source for Virtual Reality Applications

OpenAIRE

Kose, Ahmet; Tepljakov, Aleksei; Astapov, Sergei; Draheim, Dirk; Petlenkov, Eduard; Vassiljeva, Kristina

2018-01-01

In this paper, we present our findings related to the problem of localization and visualization of a sound source placed in the same room as the listener. The particular effect that we aim to investigate is called synesthesia—the act of experiencing one sense modality as another, e.g., a person may vividly experience flashes of colors when listening to a series of sounds. Towards that end, we apply a series of recently developed methods for detecting sound source in a three-dimensional space ...

A unified approach for the spatial enhancement of sound

Science.gov (United States)

Choi, Joung-Woo; Jang, Ji-Ho; Kim, Yang-Hann

2005-09-01

This paper aims to control the sound field spatially, so that the desired or target acoustic variable is enhanced within a zone where a listener is located. This is somewhat analogous to having manipulators that can draw sounds in any place. This also means that one can somehow see the controlled shape of sound in frequency or in real time. The former assures its practical applicability, for example, listening zone control for music. The latter provides a mean of analyzing sound field. With all these regards, a unified approach is proposed that can enhance selected acoustic variables using multiple sources. Three kinds of acoustic variables that have to do with magnitude and direction of sound field are formulated and enhanced. The first one, which has to do with the spatial control of acoustic potential energy, enables one to make a zone of loud sound over an area. Otherwise, one can control directional characteristic of sound field by controlling directional energy density, or one can enhance the magnitude and direction of sound at the same time by controlling acoustic intensity. Throughout various examples, it is shown that these acoustic variables can be controlled successfully by the proposed approach.

Active control of turbulent boundary layer sound transmission into a vehicle interior

International Nuclear Information System (INIS)

Caiazzo, A; Alujević, N; Pluymers, B; Desmet, W

2016-01-01

In high speed automotive, aerospace, and railway transportation, the turbulent boundary layer (TBL) is one of the most important sources of interior noise. The stochastic pressure distribution associated with the turbulence is able to excite significantly structural vibration of vehicle exterior panels. They radiate sound into the vehicle through the interior panels. Therefore, the air flow noise becomes very influential when it comes to the noise vibration and harshness assessment of a vehicle, in particular at low frequencies. Normally, passive solutions, such as sound absorbing materials, are used for reducing the TBL-induced noise transmission into a vehicle interior, which generally improve the structure sound isolation performance. These can achieve excellent isolation performance at higher frequencies, but are unable to deal with the low-frequency interior noise components. In this paper, active control of TBL noise transmission through an acoustically coupled double panel system into a rectangular cavity is examined theoretically. The Corcos model of the TBL pressure distribution is used to model the disturbance. The disturbance is rejected by an active vibration isolation unit reacting between the exterior and the interior panels. Significant reductions of the low-frequency vibrations of the interior panel and the sound pressure in the cavity are observed. (paper)

Active Noise Control Experiments using Sound Energy Flu

Science.gov (United States)

Krause, Uli

2015-03-01

This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

A SOUND SOURCE LOCALIZATION TECHNIQUE TO SUPPORT SEARCH AND RESCUE IN LOUD NOISE ENVIRONMENTS

Science.gov (United States)

Yoshinaga, Hiroshi; Mizutani, Koichi; Wakatsuki, Naoto

At some sites of earthquakes and other disasters, rescuers search for people buried under rubble by listening for the sounds which they make. Thus developing a technique to localize sound sources amidst loud noise will support such search and rescue operations. In this paper, we discuss an experiment performed to test an array signal processing technique which searches for unperceivable sound in loud noise environments. Two speakers simultaneously played a noise of a generator and a voice decreased by 20 dB (= 1/100 of power) from the generator noise at an outdoor space where cicadas were making noise. The sound signal was received by a horizontally set linear microphone array 1.05 m in length and consisting of 15 microphones. The direction and the distance of the voice were computed and the sound of the voice was extracted and played back as an audible sound by array signal processing.

Sound Spectrum Influences Auditory Distance Perception of Sound Sources Located in a Room Environment

Directory of Open Access Journals (Sweden)

Ignacio Spiousas

2017-06-01

Full Text Available Previous studies on the effect of spectral content on auditory distance perception (ADP focused on the physically measurable cues occurring either in the near field (low-pass filtering due to head diffraction or when the sound travels distances >15 m (high-frequency energy losses due to air absorption. Here, we study how the spectrum of a sound arriving from a source located in a reverberant room at intermediate distances (1–6 m influences the perception of the distance to the source. First, we conducted an ADP experiment using pure tones (the simplest possible spectrum of frequencies 0.5, 1, 2, and 4 kHz. Then, we performed a second ADP experiment with stimuli consisting of continuous broadband and bandpass-filtered (with center frequencies of 0.5, 1.5, and 4 kHz and bandwidths of 1/12, 1/3, and 1.5 octave pink-noise clips. Our results showed an effect of the stimulus frequency on the perceived distance both for pure tones and filtered noise bands: ADP was less accurate for stimuli containing energy only in the low-frequency range. Analysis of the frequency response of the room showed that the low accuracy observed for low-frequency stimuli can be explained by the presence of sparse modal resonances in the low-frequency region of the spectrum, which induced a non-monotonic relationship between binaural intensity and source distance. The results obtained in the second experiment suggest that ADP can also be affected by stimulus bandwidth but in a less straightforward way (i.e., depending on the center frequency, increasing stimulus bandwidth could have different effects. Finally, the analysis of the acoustical cues suggests that listeners judged source distance using mainly changes in the overall intensity of the auditory stimulus with distance rather than the direct-to-reverberant energy ratio, even for low-frequency noise bands (which typically induce high amount of reverberation. The results obtained in this study show that, depending on

Noise source separation of diesel engine by combining binaural sound localization method and blind source separation method

Science.gov (United States)

Yao, Jiachi; Xiang, Yang; Qian, Sichong; Li, Shengyang; Wu, Shaowei

2017-11-01

In order to separate and identify the combustion noise and the piston slap noise of a diesel engine, a noise source separation and identification method that combines a binaural sound localization method and blind source separation method is proposed. During a diesel engine noise and vibration test, because a diesel engine has many complex noise sources, a lead covering method was carried out on a diesel engine to isolate other interference noise from the No. 1-5 cylinders. Only the No. 6 cylinder parts were left bare. Two microphones that simulated the human ears were utilized to measure the radiated noise signals 1 m away from the diesel engine. First, a binaural sound localization method was adopted to separate the noise sources that are in different places. Then, for noise sources that are in the same place, a blind source separation method is utilized to further separate and identify the noise sources. Finally, a coherence function method, continuous wavelet time-frequency analysis method, and prior knowledge of the diesel engine are combined to further identify the separation results. The results show that the proposed method can effectively separate and identify the combustion noise and the piston slap noise of a diesel engine. The frequency of the combustion noise and the piston slap noise are respectively concentrated at 4350 Hz and 1988 Hz. Compared with the blind source separation method, the proposed method has superior separation and identification effects, and the separation results have fewer interference components from other noise.

An adaptive, data driven sound field control strategy for outdoor concerts

DEFF Research Database (Denmark)

Heuchel, Franz Maria; Caviedes Nozal, Diego; Brunskog, Jonas

2017-01-01

One challenge of outdoor concerts is to ensure adequate levels for the audience while avoiding disturbance of the surroundings. We outline the initial concept of a sound field control (SFC) system for tackling this issue using sound-zoning. The system uses Bayesian inference to update a sound...

The Encoding of Sound Source Elevation in the Human Auditory Cortex.

Science.gov (United States)

Trapeau, Régis; Schönwiesner, Marc

2018-03-28

tuning functions in low-level auditory cortex underlie the perceived elevation of a sound source. Copyright © 2018 the authors 0270-6474/18/383252-13$15.00/0.

Localization of Simultaneous Moving Sound Sources for Mobile Robot Using a Frequency-Domain Steered Beamformer Approach

OpenAIRE

Valin, Jean-Marc; Michaud, François; Hadjou, Brahim; Rouat, Jean

2016-01-01

Mobile robots in real-life settings would benefit from being able to localize sound sources. Such a capability can nicely complement vision to help localize a person or an interesting event in the environment, and also to provide enhanced processing for other capabilities such as speech recognition. In this paper we present a robust sound source localization method in three-dimensional space using an array of 8 microphones. The method is based on a frequency-domain implementation of a steered...

Techniques and instrumentation for the measurement of transient sound energy flux

Science.gov (United States)

Watkinson, P. S.; Fahy, F. J.

1983-12-01

The evaluation of sound intensity distributions, and sound powers, of essentially continuous sources such as automotive engines, electric motors, production line machinery, furnaces, earth moving machinery and various types of process plants were studied. Although such systems are important sources of community disturbance and, to a lesser extent, of industrial health hazard, the most serious sources of hearing hazard in industry are machines operating on an impact principle, such as drop forges, hammers and punches. Controlled experiments to identify major noise source regions and mechanisms are difficult because it is normally impossible to install them in quiet, anechoic environments. The potential for sound intensity measurement to provide a means of overcoming these difficulties has given promising results, indicating the possibility of separation of directly radiated and reverberant sound fields. However, because of the complexity of transient sound fields, a fundamental investigation is necessary to establish the practicability of intensity field decomposition, which is basic to source characterization techniques.

Extended nonnegative tensor factorisation models for musical sound source separation.

Science.gov (United States)

FitzGerald, Derry; Cranitch, Matt; Coyle, Eugene

2008-01-01

Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.

Extended Nonnegative Tensor Factorisation Models for Musical Sound Source Separation

Directory of Open Access Journals (Sweden)

Derry FitzGerald

2008-01-01

Full Text Available Recently, shift-invariant tensor factorisation algorithms have been proposed for the purposes of sound source separation of pitched musical instruments. However, in practice, existing algorithms require the use of log-frequency spectrograms to allow shift invariance in frequency which causes problems when attempting to resynthesise the separated sources. Further, it is difficult to impose harmonicity constraints on the recovered basis functions. This paper proposes a new additive synthesis-based approach which allows the use of linear-frequency spectrograms as well as imposing strict harmonic constraints, resulting in an improved model. Further, these additional constraints allow the addition of a source filter model to the factorisation framework, and an extended model which is capable of separating mixtures of pitched and percussive instruments simultaneously.

Active sound reduction system and method

NARCIS (Netherlands)

2016-01-01

The present invention refers to an active sound reduction system and method for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being. This system comprises a primary sound source, at least one speaker as a secondary sound

Parameterizing Sound: Design Considerations for an Environmental Sound Database

Science.gov (United States)

2015-04-01

associated with, or produced by, a physical event or human activity and 2) sound sources that are common in the environment. Reproductions or sound...Rogers S. Confrontation naming of environmental sounds. Journal of Clinical and Experimental Neuropsychology . 2000;22(6):830–864. 14 VanDerveer NJ

Brain responses to sound intensity changes dissociate depressed participants and healthy controls.

Science.gov (United States)

Ruohonen, Elisa M; Astikainen, Piia

2017-07-01

Depression is associated with bias in emotional information processing, but less is known about the processing of neutral sensory stimuli. Of particular interest is processing of sound intensity which is suggested to indicate central serotonergic function. We tested weather event-related brain potentials (ERPs) to occasional changes in sound intensity can dissociate first-episode depressed, recurrent depressed and healthy control participants. The first-episode depressed showed larger N1 amplitude to deviant sounds compared to recurrent depression group and control participants. In addition, both depression groups, but not the control group, showed larger N1 amplitude to deviant than standard sounds. Whether these manifestations of sensory over-excitability in depression are directly related to the serotonergic neurotransmission requires further research. The method based on ERPs to sound intensity change is fast and low-cost way to objectively measure brain activation and holds promise as a future diagnostic tool. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Freestream Turbulence on Cavity Tone and Sound Source

Directory of Open Access Journals (Sweden)

Hiroshi Yokoyama

2016-01-01

Full Text Available To clarify the effects of freestream turbulence on cavity tones, flow and acoustic fields were directly predicted for cavity flows with various intensities of freestream turbulence. The freestream Mach number was 0.09 and the Reynolds number based on the cavity length was 4.0 × 104. The depth-to-length ratio of the cavity, D/L, was 0.5 and 2.5, where the acoustic resonance of a depth-mode occurs for D/L = 2.5. The incoming boundary layer was laminar. The results for the intensity of freestream turbulence of Tu = 2.3% revealed that the reduced level of cavity tones in a cavity flow with acoustic resonance (D/L=2.5 was greater than that without acoustic resonance (D/L=0.5. To clarify the reason for this, the sound source based on Lighthill’s acoustic analogy was computed, and the contributions of the intensity and spanwise coherence of the sound source to the reduction of the cavity tone were estimated. As a result, the effects of the reduction of spanwise coherence on the cavity tone were greater in the cavity flow with acoustic resonance than in that without resonance, while the effects of the intensity were comparable for both flows.

Sound field control for a low-frequency test facility

DEFF Research Database (Denmark)

Pedersen, Christian Sejer; Møller, Henrik

2013-01-01

The two largest problems in controlling the reproduction of low-frequency sound for psychoacoustic experiments is the effect of the room due to standing waves and the relatively large sound pressure levels needed. Anechoic rooms are limited downward in frequency and distortion may be a problem even...... at moderate levels, while pressure-field playback can give higher sound pressures but is limited upwards in frequency. A new solution that addresses both problems has been implemented in the laboratory of Acoustics, Aalborg University. The solution uses one wall with 20 loudspeakers to generate a plane wave...... that is actively absorbed when it reaches the 20 loudspeakers on the opposing wall. This gives a homogeneous sound field in the majority of the room with a flat frequency response in the frequency range 2-300 Hz. The lowest frequencies are limited to sound pressure levels in the order of 95 dB. If larger levels...

Olfaction and Hearing Based Mobile Robot Navigation for Odor/Sound Source Search

Science.gov (United States)

Song, Kai; Liu, Qi; Wang, Qi

2011-01-01

Bionic technology provides a new elicitation for mobile robot navigation since it explores the way to imitate biological senses. In the present study, the challenging problem was how to fuse different biological senses and guide distributed robots to cooperate with each other for target searching. This paper integrates smell, hearing and touch to design an odor/sound tracking multi-robot system. The olfactory robot tracks the chemical odor plume step by step through information fusion from gas sensors and airflow sensors, while two hearing robots localize the sound source by time delay estimation (TDE) and the geometrical position of microphone array. Furthermore, this paper presents a heading direction based mobile robot navigation algorithm, by which the robot can automatically and stably adjust its velocity and direction according to the deviation between the current heading direction measured by magnetoresistive sensor and the expected heading direction acquired through the odor/sound localization strategies. Simultaneously, one robot can communicate with the other robots via a wireless sensor network (WSN). Experimental results show that the olfactory robot can pinpoint the odor source within the distance of 2 m, while two hearing robots can quickly localize and track the olfactory robot in 2 min. The devised multi-robot system can achieve target search with a considerable success ratio and high stability. PMID:22319401

Olfaction and Hearing Based Mobile Robot Navigation for Odor/Sound Source Search

Directory of Open Access Journals (Sweden)

Qi Wang

2011-02-01

Full Text Available Bionic technology provides a new elicitation for mobile robot navigation since it explores the way to imitate biological senses. In the present study, the challenging problem was how to fuse different biological senses and guide distributed robots to cooperate with each other for target searching. This paper integrates smell, hearing and touch to design an odor/sound tracking multi-robot system. The olfactory robot tracks the chemical odor plume step by step through information fusion from gas sensors and airflow sensors, while two hearing robots localize the sound source by time delay estimation (TDE and the geometrical position of microphone array. Furthermore, this paper presents a heading direction based mobile robot navigation algorithm, by which the robot can automatically and stably adjust its velocity and direction according to the deviation between the current heading direction measured by magnetoresistive sensor and the expected heading direction acquired through the odor/sound localization strategies. Simultaneously, one robot can communicate with the other robots via a wireless sensor network (WSN. Experimental results show that the olfactory robot can pinpoint the odor source within the distance of 2 m, while two hearing robots can quickly localize and track the olfactory robot in 2 min. The devised multi-robot system can achieve target search with a considerable success ratio and high stability.

Competing sound sources reveal spatial effects in cortical processing.

Directory of Open Access Journals (Sweden)

Ross K Maddox

Full Text Available Why is spatial tuning in auditory cortex weak, even though location is important to object recognition in natural settings? This question continues to vex neuroscientists focused on linking physiological results to auditory perception. Here we show that the spatial locations of simultaneous, competing sound sources dramatically influence how well neural spike trains recorded from the zebra finch field L (an analog of mammalian primary auditory cortex encode source identity. We find that the location of a birdsong played in quiet has little effect on the fidelity of the neural encoding of the song. However, when the song is presented along with a masker, spatial effects are pronounced. For each spatial configuration, a subset of neurons encodes song identity more robustly than others. As a result, competing sources from different locations dominate responses of different neural subpopulations, helping to separate neural responses into independent representations. These results help elucidate how cortical processing exploits spatial information to provide a substrate for selective spatial auditory attention.

Evolution of Sound Source Localization Circuits in the Nonmammalian Vertebrate Brainstem

DEFF Research Database (Denmark)

Walton, Peggy L; Christensen-Dalsgaard, Jakob; Carr, Catherine E

2017-01-01

The earliest vertebrate ears likely subserved a gravistatic function for orientation in the aquatic environment. However, in addition to detecting acceleration created by the animal's own movements, the otolithic end organs that detect linear acceleration would have responded to particle movement...... to increased sensitivity to a broader frequency range and to modification of the preexisting circuitry for sound source localization....

Three-Axis Gasless Sounding Rocket Payload Attitude Control

Data.gov (United States)

National Aeronautics and Space Administration — Gas released by current sounding rocket payload attitude control systems (ACS) has the potential to interfere with some types of science instruments. A single-axis...

Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection.

Directory of Open Access Journals (Sweden)

Andrew D Brown

Full Text Available Hearing protection devices (HPDs such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement environments where auditory situational awareness is imperative. Here we assessed (1 sound source localization accuracy using a head-turning paradigm, (2 speech-in-noise recognition using a modified version of the QuickSIN test, and (3 tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive, including two new and previously untested devices. Relative to unoccluded (control performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions.

Sound Source Localization through 8 MEMS Microphones Array Using a Sand-Scorpion-Inspired Spiking Neural Network.

Science.gov (United States)

Beck, Christoph; Garreau, Guillaume; Georgiou, Julius

2016-01-01

Sand-scorpions and many other arachnids perceive their environment by using their feet to sense ground waves. They are able to determine amplitudes the size of an atom and locate the acoustic stimuli with an accuracy of within 13° based on their neuronal anatomy. We present here a prototype sound source localization system, inspired from this impressive performance. The system presented utilizes custom-built hardware with eight MEMS microphones, one for each foot, to acquire the acoustic scene, and a spiking neural model to localize the sound source. The current implementation shows smaller localization error than those observed in nature.

On the relevance of source effects in geomagnetic pulsations for induction soundings

Science.gov (United States)

Neska, Anne; Tadeusz Reda, Jan; Leszek Neska, Mariusz; Petrovich Sumaruk, Yuri

2018-03-01

This study is an attempt to close a gap between recent research on geomagnetic pulsations and their usage as source signals in electromagnetic induction soundings (i.e., magnetotellurics, geomagnetic depth sounding, and magnetovariational sounding). The plane-wave assumption as a precondition for the proper performance of these methods is partly violated by the local nature of field line resonances which cause a considerable portion of pulsations at mid latitudes. It is demonstrated that and explained why in spite of this, the application of remote reference stations in quasi-global distances for the suppression of local correlated-noise effects in induction arrows is possible in the geomagnetic pulsation range. The important role of upstream waves and of the magnetic equatorial region for such applications is emphasized. Furthermore, the principal difference between application of reference stations for local transfer functions (which result in sounding curves and induction arrows) and for inter-station transfer functions is considered. The preconditions for the latter are much stricter than for the former. Hence a failure to estimate an inter-station transfer function to be interpreted in terms of electromagnetic induction, e.g., because of field line resonances, does not necessarily prohibit use of the station pair for a remote reference estimation of the impedance tensor.

On the relevance of source effects in geomagnetic pulsations for induction soundings

Directory of Open Access Journals (Sweden)

A. Neska

2018-03-01

Full Text Available This study is an attempt to close a gap between recent research on geomagnetic pulsations and their usage as source signals in electromagnetic induction soundings (i.e., magnetotellurics, geomagnetic depth sounding, and magnetovariational sounding. The plane-wave assumption as a precondition for the proper performance of these methods is partly violated by the local nature of field line resonances which cause a considerable portion of pulsations at mid latitudes. It is demonstrated that and explained why in spite of this, the application of remote reference stations in quasi-global distances for the suppression of local correlated-noise effects in induction arrows is possible in the geomagnetic pulsation range. The important role of upstream waves and of the magnetic equatorial region for such applications is emphasized. Furthermore, the principal difference between application of reference stations for local transfer functions (which result in sounding curves and induction arrows and for inter-station transfer functions is considered. The preconditions for the latter are much stricter than for the former. Hence a failure to estimate an inter-station transfer function to be interpreted in terms of electromagnetic induction, e.g., because of field line resonances, does not necessarily prohibit use of the station pair for a remote reference estimation of the impedance tensor.

Regularization in global sound equalization based on effort variation

DEFF Research Database (Denmark)

Stefanakis, Nick; Sarris, John; Jacobsen, Finn

2009-01-01

. Effort variation equalization involves modifying the conventional cost function in sound equalization, which is based on minimizing least-squares reproduction errors, by adding a term that is proportional to the squared deviations between complex source strengths, calculated independently for the sources......Sound equalization in closed spaces can be significantly improved by generating propagating waves that are naturally associated with the geometry, as, for example, plane waves in rectangular enclosures. This paper presents a control approach termed effort variation regularization based on this idea...

A location procedure for sound sources in reactor-technical enclosures

International Nuclear Information System (INIS)

Hamann, D.

1982-07-01

A passive method requiring one detector only has been developed for the location of sound emitting faults in nuclear power plant components. It is adapted for use in a frequency range the wavelength of which is of the same order of magnitude as characteristic dimensions of the considered enclosure. The location is performed in the following way: (1) For a fixed detector position the Auto Power Spectral Density (APSD) of the source to be located is measured. (2) For this detector position the APSD is calculated for the potential source locations. For this, the free-field APSD as well as the acoustic normal modes of the enclosure are necessary. (3) The measured APSD is compared with the theoretically obtained APSD's. (4) That APSD is determined which is most similar to the measured APSD, and consequently an information about the unknown source position is got. (author)

The effect of sound speed profile on shallow water shipping sound maps

NARCIS (Netherlands)

Sertlek, H.Ö.; Binnerts, B.; Ainslie, M.A.

2016-01-01

Sound mapping over large areas can be computationally expensive because of the large number of sources and large source-receiver separations involved. In order to facilitate computation, a simplifying assumption sometimes made is to neglect the sound speed gradient in shallow water. The accuracy of

Sound Source Localization Through 8 MEMS Microphones Array Using a Sand-Scorpion-Inspired Spiking Neural Network

Directory of Open Access Journals (Sweden)

Christoph Beck

2016-10-01

Full Text Available Sand-scorpions and many other arachnids perceive their environment by using their feet to sense ground waves. They are able to determine amplitudes the size of an atom and locate the acoustic stimuli with an accuracy of within 13° based on their neuronal anatomy. We present here a prototype sound source localization system, inspired from this impressive performance. The system presented utilizes custom-built hardware with eight MEMS microphones, one for each foot, to acquire the acoustic scene, and a spiking neural model to localize the sound source. The current implementation shows smaller localization error than those observed in nature.

Sound source measurement by using a passive sound insulation and a statistical approach

Science.gov (United States)

Dragonetti, Raffaele; Di Filippo, Sabato; Mercogliano, Francesco; Romano, Rosario A.

2015-10-01

This paper describes a measurement technique developed by the authors that allows carrying out acoustic measurements inside noisy environments reducing background noise effects. The proposed method is based on the integration of a traditional passive noise insulation system with a statistical approach. The latter is applied to signals picked up by usual sensors (microphones and accelerometers) equipping the passive sound insulation system. The statistical approach allows improving of the sound insulation given only by the passive sound insulation system at low frequency. The developed measurement technique has been validated by means of numerical simulations and measurements carried out inside a real noisy environment. For the case-studies here reported, an average improvement of about 10 dB has been obtained in a frequency range up to about 250 Hz. Considerations on the lower sound pressure level that can be measured by applying the proposed method and the measurement error related to its application are reported as well.

Low frequency sound field control in rectangular listening rooms using CABS (Controlled Acoustic Bass System) will also reduce sound transmission to neighbor rooms

DEFF Research Database (Denmark)

Nielsen, Sofus Birkedal; Celestinos, Adrian

2011-01-01

Sound reproduction is often taking place in small and medium sized rectangular rooms. As rectangular rooms have 3 pairs of parallel walls the reflections at especially low frequencies will cause up to 30 dB spatial variations of the sound pressure level in the room. This will take place not only...... at resonance frequencies, but more or less at all frequencies. A time based room correction system named CABS (Controlled Acoustic Bass System) has been developed and is able to create a homogeneous sound field in the whole room at low frequencies by proper placement of multiple loudspeakers. A normal setup...... from the rear wall, and thereby leaving only the plane wave in the room. With a room size of (7.8 x 4.1 x 2.8) m. it is possible to prevent modal frequencies up to 100 Hz. An investigation has shown that the sound transmitted to a neighbour room also will be reduced if CABS is used. The principle...

Vehicle engine sound design based on an active noise control system

Energy Technology Data Exchange (ETDEWEB)

Lewis, M. [Siemens VDO Automotive, Auburn Hills, MI (United States)

2002-07-01

A study has been carried out to identify the types of vehicle engine sounds that drivers prefer while driving at different locations and under different driving conditions. An active noise control system controlled the sound at the air intake orifice of a vehicle engine's first sixteen orders and half orders. The active noise control system was used to change the engine sound to quiet, harmonic, high harmonic, spectral shaped and growl. Videos were made of the roads traversed, binaural recording of vehicle interior sounds, and vibrations of the vehicle floor pan. Jury tapes were made up for day driving, nighttime driving and driving in the rain during the day for each of the sites. Jurors used paired comparisons to evaluate the vehicle interior sounds while sitting in a vehicle simulator developed by Siemens VDO that replicated videos of the road traversed, binaural recording of the vehicle interior sounds and vibrations of the floor pan and seat. (orig.) [German] Im Rahmen einer Studie wurden Typen von Motorgeraeuschen identifiziert, die von Fahrern unter verschiedenen Fahrbedingungen als angenehm empfunden werden. Ein System zur aktiven Geraeuschbeeinflussung am Ansauglufteinlass im Bereich des Luftfilters modifizierte den Klang des Motors bis zur 16,5ten Motorordnung, und zwar durch Bedaempfung, Verstaerkung und Filterung der Signalfrequenzen. Waehrend der Fahrt wurden Videoaufnahmen der befahrenen Strassen, Stereoaufnahmen der Fahrzeuginnengeraeusche und Aufnahmen der Vibrationsamplituden des Fahrzeugbodens erstellt; dies bei Tag- und Nachtfahrten und bei Tagfahrten im Regen. Zur Beurteilung der aufgezeichneten Geraeusche durch Versuchspersonen wurde ein Fahrzeug-Laborsimulator mit Fahrersitz, Bildschirm, Lautsprecher und mechanischer Erregung der Bodenplatte aufgebaut, um die aufgenommenen Signale moeglichst wirklichkeitsgetreu wiederzugeben. (orig.)

Perception by Operators of Approach and Withdrawal of Moving Sound Sources

Science.gov (United States)

1999-01-01

Tucker, 1988; Strybel and Neal, 1994) or between stationary and moving sound sources or auditory images (Perrott and Musikant , 1977; Strybel and Neale...conditions of stimulation (Viskov, 1975; Perrott and Musikant , 1977; Strybel et al., 1989; Sabery and Perrott, 1990; Strybel et al., 1992; Strybel and...noise and its relation to masking and loudness// JASA, 1947. V.19. P. 609-619. 24. Perrott D.R., Musicant A.D. Minimum auditory movement angle: binaural

Mapping Strategies and Sound Engine Design for an Augmented Hybrid Piano

DEFF Research Database (Denmark)

Dahlstedt, Palle

2015-01-01

Based on a combination of novel mapping techniques and carefully designed sound engines, I present an augmented hybrid piano specifically designed for improvisation. The mapping technique, originally developed for other control interfaces but here adapted to the piano keyboard, is based...... on a dynamic vectorization of control parameters, allowing both wild sonic exploration and minute intimate expression. The original piano sound is used as the sole sound source, subjected to processing techniques such as virtual resonance strings, dynamic buffer shuffling, and acoustic and virtual feedback....... Thanks to speaker and microphone placement, the acoustic and processed sounds interact in both directions and blend into one new instrument. This also allows for unorthodox playing (knocking, plucking, shouting). Processing parameters are controlled from the keyboard playing alone, allowing intuitive...

Sustainable Acoustic Metasurfaces for Sound Control

Directory of Open Access Journals (Sweden)

Paola Gori

2016-01-01

Full Text Available Sound attenuation with conventional acoustic materials is subject to the mass law and requires massive and bulky structures at low frequencies. A possible alternative solution is provided by the use of metamaterials, which are artificial materials properly engineered to obtain properties and characteristics that it is not possible to find in natural materials. Theory and applications of metamaterials, already consolidated in electromagnetism, can be extended to acoustics; in particular, they can be applied to improve the properties of acoustical panels. The design of acoustic metasurfaces that could effectively control transmitted sound in unconventional ways appears a significant subject to be investigated, given its wide-ranging possible applications. In this contribution, we investigate the application of a metasurface-inspired technique to achieve the acoustical insulation of an environment. The designed surface has subwavelength thickness and structuring and could be realized with cheap, lightweight and sustainable materials. We present a few examples of such structures and analyze their acoustical behavior by means of full-wave simulations.

WAVE: Interactive Wave-based Sound Propagation for Virtual Environments.

Science.gov (United States)

Mehra, Ravish; Rungta, Atul; Golas, Abhinav; Ming Lin; Manocha, Dinesh

2015-04-01

We present an interactive wave-based sound propagation system that generates accurate, realistic sound in virtual environments for dynamic (moving) sources and listeners. We propose a novel algorithm to accurately solve the wave equation for dynamic sources and listeners using a combination of precomputation techniques and GPU-based runtime evaluation. Our system can handle large environments typically used in VR applications, compute spatial sound corresponding to listener's motion (including head tracking) and handle both omnidirectional and directional sources, all at interactive rates. As compared to prior wave-based techniques applied to large scenes with moving sources, we observe significant improvement in runtime memory. The overall sound-propagation and rendering system has been integrated with the Half-Life 2 game engine, Oculus-Rift head-mounted display, and the Xbox game controller to enable users to experience high-quality acoustic effects (e.g., amplification, diffraction low-passing, high-order scattering) and spatial audio, based on their interactions in the VR application. We provide the results of preliminary user evaluations, conducted to study the impact of wave-based acoustic effects and spatial audio on users' navigation performance in virtual environments.

Performance of an open-source heart sound segmentation algorithm on eight independent databases.

Science.gov (United States)

Liu, Chengyu; Springer, David; Clifford, Gari D

2017-08-01

Heart sound segmentation is a prerequisite step for the automatic analysis of heart sound signals, facilitating the subsequent identification and classification of pathological events. Recently, hidden Markov model-based algorithms have received increased interest due to their robustness in processing noisy recordings. In this study we aim to evaluate the performance of the recently published logistic regression based hidden semi-Markov model (HSMM) heart sound segmentation method, by using a wider variety of independently acquired data of varying quality. Firstly, we constructed a systematic evaluation scheme based on a new collection of heart sound databases, which we assembled for the PhysioNet/CinC Challenge 2016. This collection includes a total of more than 120 000 s of heart sounds recorded from 1297 subjects (including both healthy subjects and cardiovascular patients) and comprises eight independent heart sound databases sourced from multiple independent research groups around the world. Then, the HSMM-based segmentation method was evaluated using the assembled eight databases. The common evaluation metrics of sensitivity, specificity, accuracy, as well as the [Formula: see text] measure were used. In addition, the effect of varying the tolerance window for determining a correct segmentation was evaluated. The results confirm the high accuracy of the HSMM-based algorithm on a separate test dataset comprised of 102 306 heart sounds. An average [Formula: see text] score of 98.5% for segmenting S1 and systole intervals and 97.2% for segmenting S2 and diastole intervals were observed. The [Formula: see text] score was shown to increases with an increases in the tolerance window size, as expected. The high segmentation accuracy of the HSMM-based algorithm on a large database confirmed the algorithm's effectiveness. The described evaluation framework, combined with the largest collection of open access heart sound data, provides essential resources for

A "looming bias" in spatial hearing? Effects of acoustic intensity and spectrum on categorical sound source localization.

Science.gov (United States)

McCarthy, Lisa; Olsen, Kirk N

2017-01-01

Continuous increases of acoustic intensity (up-ramps) can indicate a looming (approaching) sound source in the environment, whereas continuous decreases of intensity (down-ramps) can indicate a receding sound source. From psychoacoustic experiments, an "adaptive perceptual bias" for up-ramp looming tonal stimuli has been proposed (Neuhoff, 1998). This theory postulates that (1) up-ramps are perceptually salient because of their association with looming and potentially threatening stimuli in the environment; (2) tonal stimuli are perceptually salient because of an association with single and potentially threatening biological sound sources in the environment, relative to white noise, which is more likely to arise from dispersed signals and nonthreatening/nonbiological sources (wind/ocean). In the present study, we extrapolated the "adaptive perceptual bias" theory and investigated its assumptions by measuring sound source localization in response to acoustic stimuli presented in azimuth to imply looming, stationary, and receding motion in depth. Participants (N = 26) heard three directions of intensity change (up-ramps, down-ramps, and steady state, associated with looming, receding, and stationary motion, respectively) and three levels of acoustic spectrum (a 1-kHz pure tone, the tonal vowel /ә/, and white noise) in a within-subjects design. We first hypothesized that if up-ramps are "perceptually salient" and capable of eliciting adaptive responses, then they would be localized faster and more accurately than down-ramps. This hypothesis was supported. However, the results did not support the second hypothesis. Rather, the white-noise and vowel conditions were localized faster and more accurately than the pure-tone conditions. These results are discussed in the context of auditory and visual theories of motion perception, auditory attentional capture, and the spectral causes of spatial ambiguity.

Active control of radiated sound power from a baffled, rectangular panel

DEFF Research Database (Denmark)

Mørkholt, Jakob

1996-01-01

with an array of eleven microphones in front of the panel, is very close to minimising the actual radiated sound power. Practical experiments where such an array estimate has been minimised using the filtered X LMS algorithm have shown that substantial reductions of radiated sound power can be obtained over......Active control of radiated sound power from a rectangular baffled panel by minimisation of an accurate power estimate, using piezoceramic actuators, has been investigated. Computer simulations have shown that minimising a power estimate obtained by discretised integration of the far field intensity...... a broad frequency range using few piezoceramic actuators, provided that an accurate estimate of the sound power is available for minimisation....

Physically based sound synthesis and control of jumping sounds on an elastic trampoline

DEFF Research Database (Denmark)

Turchet, Luca; Pugliese, Roberto; Takala, Tapio

2013-01-01

This paper describes a system to interactively sonify the foot-floor contacts resulting from jumping on an elastic trampoline. The sonification was achieved by means of a synthesis engine based on physical models reproducing the sounds of jumping on several surface materials. The engine was contr......This paper describes a system to interactively sonify the foot-floor contacts resulting from jumping on an elastic trampoline. The sonification was achieved by means of a synthesis engine based on physical models reproducing the sounds of jumping on several surface materials. The engine...... was controlled in real-time by pro- cessing the signal captured by a contact microphone which was attached to the membrane of the trampoline in order to detect each jump. A user study was conducted to evaluate the quality of the in- teractive sonification. Results proved the success of the proposed algorithms...

The effect of multimicrophone noise reduction systems on sound source localization by users of binaural hearing aids.

Science.gov (United States)

Van den Bogaert, Tim; Doclo, Simon; Wouters, Jan; Moonen, Marc

2008-07-01

This paper evaluates the influence of three multimicrophone noise reduction algorithms on the ability to localize sound sources. Two recently developed noise reduction techniques for binaural hearing aids were evaluated, namely, the binaural multichannel Wiener filter (MWF) and the binaural multichannel Wiener filter with partial noise estimate (MWF-N), together with a dual-monaural adaptive directional microphone (ADM), which is a widely used noise reduction approach in commercial hearing aids. The influence of the different algorithms on perceived sound source localization and their noise reduction performance was evaluated. It is shown that noise reduction algorithms can have a large influence on localization and that (a) the ADM only preserves localization in the forward direction over azimuths where limited or no noise reduction is obtained; (b) the MWF preserves localization of the target speech component but may distort localization of the noise component. The latter is dependent on signal-to-noise ratio and masking effects; (c) the MWF-N enables correct localization of both the speech and the noise components; (d) the statistical Wiener filter approach introduces a better combination of sound source localization and noise reduction performance than the ADM approach.

Control of Toxic Chemicals in Puget Sound, Phase 3: Study of Atmospheric Deposition of Air Toxics to the Surface of Puget Sound

Energy Technology Data Exchange (ETDEWEB)

Brandenberger, Jill M.; Louchouarn, Patrick; Kuo, Li-Jung; Crecelius, Eric A.; Cullinan, Valerie I.; Gill, Gary A.; Garland, Charity R.; Williamson, J. B.; Dhammapala, R.

2010-07-05

The results of the Phase 1 Toxics Loading study suggested that runoff from the land surface and atmospheric deposition directly to marine waters have resulted in considerable loads of contaminants to Puget Sound (Hart Crowser et al. 2007). The limited data available for atmospheric deposition fluxes throughout Puget Sound was recognized as a significant data gap. Therefore, this study provided more recent or first reported atmospheric deposition fluxes of PAHs, PBDEs, and select trace elements for Puget Sound. Samples representing bulk atmospheric deposition were collected during 2008 and 2009 at seven stations around Puget Sound spanning from Padilla Bay south to Nisqually River including Hood Canal and the Straits of Juan de Fuca. Revised annual loading estimates for atmospheric deposition to the waters of Puget Sound were calculated for each of the toxics and demonstrated an overall decrease in the atmospheric loading estimates except for polybrominated diphenyl ethers (PBDEs) and total mercury (THg). The median atmospheric deposition flux of total PBDE (7.0 ng/m2/d) was higher than that of the Hart Crowser (2007) Phase 1 estimate (2.0 ng/m2/d). The THg was not significantly different from the original estimates. The median atmospheric deposition flux for pyrogenic PAHs (34.2 ng/m2/d; without TCB) shows a relatively narrow range across all stations (interquartile range: 21.2- 61.1 ng/m2/d) and shows no influence of season. The highest median fluxes for all parameters were measured at the industrial location in Tacoma and the lowest were recorded at the rural sites in Hood Canal and Sequim Bay. Finally, a semi-quantitative apportionment study permitted a first-order characterization of source inputs to the atmosphere of the Puget Sound. Both biomarker ratios and a principal component analysis confirmed regional data from the Puget Sound and Straits of Georgia region and pointed to the predominance of biomass and fossil fuel (mostly liquid petroleum products such

Environmental quality of Long Island Sound: Assessment and management issues

International Nuclear Information System (INIS)

Wolfe, D.A.; Farrow, D.R.G.; Robertson, A.; Monahan, R.; Stacey, P.E.

1991-01-01

Estimated pollutant loadings to Long Island Sound (LIS) are presented and discussed in the context of current information on population trends and land-use characteristics within the drainage basin of the sound. For the conventional pollutants (BOD, N, and P) and for most of the metals examined, the fluxes to LIS from wastewater treatment plants approach or exceed the fluxes from riverine sources. Urban runoff is a significant source for only a few contaminants, such as lead and petroleum hydrocarbons. Atmospheric flux estimates made for other areas are extrapolated to LIS, and this source appears to be significant for lead, zinc, and polynuclear aromatic hydrocarbons, and chlorinated pesticides. Continued population growth is projected through 2010, both in the urban centers of the western sound and in the coastal counties surrounding the central and eastern portions of LIS. This growth will place increased pollution pressure on the sound and increased demands on already scarce coastal and estuarine land-use categories. Close interaction between environmental planners, managers, and scientists is required to identify effective control strategies for reducing existing pollutant stress to the sound and for minimizing the effects of future development

Turbine sound may influence the metamorphosis behaviour of estuarine crab megalopae.

Science.gov (United States)

Pine, Matthew K; Jeffs, Andrew G; Radford, Craig A

2012-01-01

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21-31% compared to silent control treatments, 38-47% compared to tidal turbine sound treatments, and 46-60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

Turbine sound may influence the metamorphosis behaviour of estuarine crab megalopae.

Directory of Open Access Journals (Sweden)

Matthew K Pine

Full Text Available It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21-31% compared to silent control treatments, 38-47% compared to tidal turbine sound treatments, and 46-60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

Propagation of sound

DEFF Research Database (Denmark)

Wahlberg, Magnus; Larsen, Ole Næsbye

2017-01-01

properties can be modified by sound absorption, refraction, and interference from multi paths caused by reflections.The path from the source to the receiver may be bent due to refraction. Besides geometrical attenuation, the ground effect and turbulence are the most important mechanisms to influence...... communication sounds for airborne acoustics and bottom and surface effects for underwater sounds. Refraction becomes very important close to shadow zones. For echolocation signals, geometric attenuation and sound absorption have the largest effects on the signals....

Design of virtual three-dimensional instruments for sound control

Science.gov (United States)

Mulder, Axel Gezienus Elith

An environment for designing virtual instruments with 3D geometry has been prototyped and applied to real-time sound control and design. It enables a sound artist, musical performer or composer to design an instrument according to preferred or required gestural and musical constraints instead of constraints based only on physical laws as they apply to an instrument with a particular geometry. Sounds can be created, edited or performed in real-time by changing parameters like position, orientation and shape of a virtual 3D input device. The virtual instrument can only be perceived through a visualization and acoustic representation, or sonification, of the control surface. No haptic representation is available. This environment was implemented using CyberGloves, Polhemus sensors, an SGI Onyx and by extending a real- time, visual programming language called Max/FTS, which was originally designed for sound synthesis. The extension involves software objects that interface the sensors and software objects that compute human movement and virtual object features. Two pilot studies have been performed, involving virtual input devices with the behaviours of a rubber balloon and a rubber sheet for the control of sound spatialization and timbre parameters. Both manipulation and sonification methods affect the naturalness of the interaction. Informal evaluation showed that a sonification inspired by the physical world appears natural and effective. More research is required for a natural sonification of virtual input device features such as shape, taking into account possible co- articulation of these features. While both hands can be used for manipulation, left-hand-only interaction with a virtual instrument may be a useful replacement for and extension of the standard keyboard modulation wheel. More research is needed to identify and apply manipulation pragmatics and movement features, and to investigate how they are co-articulated, in the mapping of virtual object

Active structural acoustic control for reduction of radiated sound from structure

International Nuclear Information System (INIS)

Hong, Jin Seok; Oh, Jae Eung

2001-01-01

Active control of sound radiation from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Structural excitation is achieved by two piezoceramic actuators mounted on the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The approach is based on a multi-channel filtered-x LMS algorithm. The results shows that attenuation of sound levels of 11dB, 10dB is achieved

Design and Calibration Tests of an Active Sound Intensity Probe

Directory of Open Access Journals (Sweden)

Thomas Kletschkowski

2008-01-01

Full Text Available The paper presents an active sound intensity probe that can be used for sound source localization in standing wave fields. The probe consists of a sound hard tube that is terminated by a loudspeaker and an integrated pair of microphones. The microphones are used to decompose the standing wave field inside the tube into its incident and reflected part. The latter is cancelled by an adaptive controller that calculates proper driving signals for the loudspeaker. If the open end of the actively controlled tube is placed close to a vibrating surface, the radiated sound intensity can be determined by measuring the cross spectral density between the two microphones. A one-dimensional free field can be realized effectively, as first experiments performed on a simplified test bed have shown. Further tests proved that a prototype of the novel sound intensity probe can be calibrated.

Time domain acoustic contrast control implementation of sound zones for low-frequency input signals

DEFF Research Database (Denmark)

Schellekens, Daan H. M.; Møller, Martin Bo; Olsen, Martin

2016-01-01

Sound zones are two or more regions within a listening space where listeners are provided with personal audio. Acoustic contrast control (ACC) is a sound zoning method that maximizes the average squared sound pressure in one zone constrained to constant pressure in other zones. State......-of-the-art time domain broadband acoustic contrast control (BACC) methods are designed for anechoic environments. These methods are not able to realize a flat frequency response in a limited frequency range within a reverberant environment. Sound field control in a limited frequency range is a requirement...... to accommodate the effective working range of the loudspeakers. In this paper, a new BACC method is proposed which results in an implementation realizing a flat frequency response in the target zone. This method is applied in a bandlimited low-frequency scenario where the loudspeaker layout surrounds two...

Active control and sound synthesis--two different ways to investigate the influence of the modal parameters of a guitar on its sound.

Science.gov (United States)

Benacchio, Simon; Mamou-Mani, Adrien; Chomette, Baptiste; Finel, Victor

2016-03-01

The vibrational behavior of musical instruments is usually studied using physical modeling and simulations. Recently, active control has proven its efficiency to experimentally modify the dynamical behavior of musical instruments. This approach could also be used as an experimental tool to systematically study fine physical phenomena. This paper proposes to use modal active control as an alternative to sound simulation to study the complex case of the coupling between classical guitar strings and soundboard. A comparison between modal active control and sound simulation investigates the advantages, the drawbacks, and the limits of these two approaches.

Turbine Sound May Influence the Metamorphosis Behaviour of Estuarine Crab Megalopae

Science.gov (United States)

Pine, Matthew K.; Jeffs, Andrew G.; Radford, Craig A.

2012-01-01

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21–31% compared to silent control treatments, 38–47% compared to tidal turbine sound treatments, and 46–60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment. PMID:23240063

Reconstruction of Sound Source Pressures in an Enclosure Using the Phased Beam Tracing Method

DEFF Research Database (Denmark)

Jeong, Cheol-Ho; Ih, Jeong-Guon

2009-01-01

. First, surfaces of an extended source are divided into reasonably small segments. From each source segment, one beam is projected into the field and all emitted beams are traced. Radiated beams from the source reach array sensors after traveling various paths including the wall reflections. Collecting...... all the pressure histories at the field points, source-observer relations can be constructed in a matrix-vector form for each frequency. By multiplying the measured field data with the pseudo-inverse of the calculated transfer function, one obtains the distribution of source pressure. An omni......-directional sphere and a cubic source in a rectangular enclosure were taken as examples in the simulation tests. A reconstruction error was investigated by Monte Carlo simulation in terms of field point locations. When the source information was reconstructed by the present method, it was shown that the sound power...

Measurement of acoustic characteristics of Japanese Buddhist temples in relation to sound source location and direction.

Science.gov (United States)

Soeta, Yoshiharu; Shimokura, Ryota; Kim, Yong Hee; Ohsawa, Tomohiro; Ito, Ken

2013-05-01

Although temples are important buildings in the Buddhist community, the acoustic quality has not been examined in detail. Buddhist monks change the location and direction according to the ceremony, and associated acoustical changes have not yet been examined scientifically. To discuss the desired acoustics of temples, it is necessary to know the acoustic characteristics appropriate for each phase of a ceremony. In this study, acoustic measurements were taken at various source locations and directions in Japanese temples. A directional loudspeaker was used as the source to provide vocal acoustic fields, and impulse responses were measured and analyzed. The speech transmission index was higher and the interaural cross-correlation coefficient was lower for the sound source directed toward the side wall than that directed toward the altar. This suggests that the change in direction improves speech intelligibility, and the asymmetric property of direct sound and complex reflections from the altar and side wall increases the apparent source width. The large and coupled-like structure of the altar of a Buddhist temple may have reinforced the reverberation components and the table in the altar, which is called the "syumidan," may have decreased binaural coherence.

Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

Science.gov (United States)

Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

2017-08-01

Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

Predicting outdoor sound

CERN Document Server

Attenborough, Keith; Horoshenkov, Kirill

2014-01-01

1. Introduction  2. The Propagation of Sound Near Ground Surfaces in a Homogeneous Medium  3. Predicting the Acoustical Properties of Outdoor Ground Surfaces  4. Measurements of the Acoustical Properties of Ground Surfaces and Comparisons with Models  5. Predicting Effects of Source Characteristics on Outdoor Sound  6. Predictions, Approximations and Empirical Results for Ground Effect Excluding Meteorological Effects  7. Influence of Source Motion on Ground Effect and Diffraction  8. Predicting Effects of Mixed Impedance Ground  9. Predicting the Performance of Outdoor Noise Barriers  10. Predicting Effects of Vegetation, Trees and Turbulence  11. Analytical Approximations including Ground Effect, Refraction and Turbulence  12. Prediction Schemes  13. Predicting Sound in an Urban Environment.

A holistic approach to hydrocarbon source allocation in the subtidal sediments of Prince William Sound, Alaska, embayments

International Nuclear Information System (INIS)

Page, D.S.; Bence, A.E.; Burns, W.A.; Boehm, P.D.; Brown, J.S.; Douglas, G.S.

2002-01-01

The complex organic geochemistry record in the subtidal sediments of Prince William Sound, Alaska is a result of much industrial and human activity in the region. Recent oil spills and a regional background of natural petroleum hydrocarbons originating from active hydrocarbon systems in the northern Gulf of Alaska also contribute to the geochemical record. Pyrogenic and petrogenic polycyclic aromatic hydrocarbons (PAH) are introduced regularly to the subtidal sediments at sites of past and present human activities including villages, fish hatcheries, fish camps and recreational campsites as well as abandoned settlements, canneries, sawmills and mines. Hydrocarbon contributions are fingerprinted and quantified using a holistic approach where contributions from multiple sources is determined. The approach involves a good understanding of the history of the area to identify potential sources. It also involves extensive collection of representative samples and an accurate quantitative analysis of the source and sediment samples for PAH analytes and chemical biomarker compounds. Total organic carbon (TOC) does not work in restricted embayments because of a constrained least-square algorithm to determine hydrocarbon sources. It has been shown that sources contributing to the natural petrogenic background are present in Prince William Sound. In particular, pyrogenic hydrocarbons such as combustion products of diesel is significant where there was much human activity. In addition, petroleum produced from the Monterey Formation in California is present in Prince William Sound because in the past, oil and asphalt shipped from California was widely used for fuel. Low level residues of weathered Alaskan North Slope crude oil from the Exxon Valdez spill are also still present. 30 refs., 4 tabs., 2 figs

Efficient techniques for wave-based sound propagation in interactive applications

Science.gov (United States)

Mehra, Ravish

Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the final point of arrival at the listener. Sound is a pressure wave produced by mechanical vibration of a surface that propagates through a medium such as air or water, and the problem of sound propagation can be formulated mathematically as a second-order partial differential equation called the wave equation. Accurate techniques based on solving the wave equation, also called the wave-based techniques, are too expensive computationally and memory-wise. Therefore, these techniques face many challenges in terms of their applicability in interactive applications including sound propagation in large environments, time-varying source and listener directivity, and high simulation cost for mid-frequencies. In this dissertation, we propose a set of efficient wave-based sound propagation techniques that solve these three challenges and enable the use of wave-based sound propagation in interactive applications. Firstly, we propose a novel equivalent source technique for interactive wave-based sound propagation in large scenes spanning hundreds of meters. It is based on the equivalent source theory used for solving radiation and scattering problems in acoustics and electromagnetics. Instead of using a volumetric or surface-based approach, this technique takes an object-centric approach to sound propagation. The proposed equivalent source technique generates realistic acoustic effects and takes orders of magnitude less runtime memory compared to prior wave-based techniques. Secondly, we present an efficient framework for handling time-varying source and listener directivity for interactive wave-based sound propagation. The source directivity is represented as a linear combination of elementary spherical harmonic sources. This spherical harmonic-based representation of source directivity can support analytical, data

On the influence of microphone array geometry on HRTF-based Sound Source Localization

DEFF Research Database (Denmark)

Farmani, Mojtaba; Pedersen, Michael Syskind; Tan, Zheng-Hua

2015-01-01

The direction dependence of Head Related Transfer Functions (HRTFs) forms the basis for HRTF-based Sound Source Localization (SSL) algorithms. In this paper, we show how spectral similarities of the HRTFs of different directions in the horizontal plane influence performance of HRTF-based SSL...... algorithms; the more similar the HRTFs of different angles to the HRTF of the target angle, the worse the performance. However, we also show how the microphone array geometry can assist in differentiating between the HRTFs of the different angles, thereby improving performance of HRTF-based SSL algorithms....... Furthermore, to demonstrate the analysis results, we show the impact of HRTFs similarities and microphone array geometry on an exemplary HRTF-based SSL algorithm, called MLSSL. This algorithm is well-suited for this purpose as it allows to estimate the Direction-of-Arrival (DoA) of the target sound using any...

Improvements on the directional characteristics of a calibration sound source using the Boundary Element Method

DEFF Research Database (Denmark)

Cutanda Henriquez, Vicente; Barrera Figueroa, Salvador; Juhl, Peter Møller

2008-01-01

The project Euromet-792 aims to investigate and improve methods for secondary free-field calibration of microphones. In this framework, the comparison method is being studied at DFM in relation to the more usual substitution method of microphone calibration. The design of the sound source is of p...

System for actively reducing sound

NARCIS (Netherlands)

Berkhoff, Arthur P.

2005-01-01

A system for actively reducing sound from a primary noise source, such as traffic noise, comprising: a loudspeaker connector for connecting to at least one loudspeaker for generating anti-sound for reducing said noisy sound; a microphone connector for connecting to at least a first microphone placed

High frequency ion sound waves associated with Langmuir waves in type III radio burst source regions

Directory of Open Access Journals (Sweden)

G. Thejappa

2004-01-01

Full Text Available Short wavelength ion sound waves (2-4kHz are detected in association with the Langmuir waves (~15-30kHz in the source regions of several local type III radio bursts. They are most probably not due to any resonant wave-wave interactions such as the electrostatic decay instability because their wavelengths are much shorter than those of Langmuir waves. The Langmuir waves occur as coherent field structures with peak intensities exceeding the Langmuir collapse thresholds. Their scale sizes are of the order of the wavelength of an ion sound wave. These Langmuir wave field characteristics indicate that the observed short wavelength ion sound waves are most probably generated during the thermalization of the burnt-out cavitons left behind by the Langmuir collapse. Moreover, the peak intensities of the observed short wavelength ion sound waves are comparable to the expected intensities of those ion sound waves radiated by the burnt-out cavitons. However, the speeds of the electron beams derived from the frequency drift of type III radio bursts are too slow to satisfy the needed adiabatic ion approximation. Therefore, some non-linear process such as the induced scattering on thermal ions most probably pumps the beam excited Langmuir waves towards the lower wavenumbers, where the adiabatic ion approximation is justified.

An intelligent artificial throat with sound-sensing ability based on laser induced graphene

Science.gov (United States)

Tao, Lu-Qi; Tian, He; Liu, Ying; Ju, Zhen-Yi; Pang, Yu; Chen, Yuan-Quan; Wang, Dan-Yang; Tian, Xiang-Guang; Yan, Jun-Chao; Deng, Ning-Qin; Yang, Yi; Ren, Tian-Ling

2017-02-01

Traditional sound sources and sound detectors are usually independent and discrete in the human hearing range. To minimize the device size and integrate it with wearable electronics, there is an urgent requirement of realizing the functional integration of generating and detecting sound in a single device. Here we show an intelligent laser-induced graphene artificial throat, which can not only generate sound but also detect sound in a single device. More importantly, the intelligent artificial throat will significantly assist for the disabled, because the simple throat vibrations such as hum, cough and scream with different intensity or frequency from a mute person can be detected and converted into controllable sounds. Furthermore, the laser-induced graphene artificial throat has the advantage of one-step fabrication, high efficiency, excellent flexibility and low cost, and it will open practical applications in voice control, wearable electronics and many other areas.

Cognitive Control of Involuntary Distraction by Deviant Sounds

Science.gov (United States)

Parmentier, Fabrice B. R.; Hebrero, Maria

2013-01-01

It is well established that a task-irrelevant sound (deviant sound) departing from an otherwise repetitive sequence of sounds (standard sounds) elicits an involuntary capture of attention and orienting response toward the deviant stimulus, resulting in the lengthening of response times in an ongoing task. Some have argued that this type of…

Sound field control with a circular double-layer array of loudspeakers

DEFF Research Database (Denmark)

Chang, Jiho; Jacobsen, Finn

2012-01-01

, and their performance is examined using computer simulations. Two performance indices are used in this work, (a) the level difference between the average sound energy density in the listening zone and that in the quiet zone (sometimes called “the acoustic contrast”), and (b) a normalized measure of the deviations...... between the desired and the generated sound field in the listening zone. It is concluded that the best compromise is obtained with a method that combines pure contrast maximization with a pressure matching technique.......This paper describes a method of generating a controlled sound field for listeners inside a circular array of loudspeakers without disturbing people outside the array appreciably. To achieve this objective, a double-layer array of loudspeakers is used. Several solution methods are suggested...

Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments

Directory of Open Access Journals (Sweden)

Kotaro Hoshiba

2017-11-01

Full Text Available In search and rescue activities, unmanned aerial vehicles (UAV should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators.

Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments.

Science.gov (United States)

Hoshiba, Kotaro; Washizaki, Kai; Wakabayashi, Mizuho; Ishiki, Takahiro; Kumon, Makoto; Bando, Yoshiaki; Gabriel, Daniel; Nakadai, Kazuhiro; Okuno, Hiroshi G

2017-11-03

In search and rescue activities, unmanned aerial vehicles (UAV) should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS) consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators.

A method for recognition of coexisting environmental sound sources based on the Fisher’s linear discriminant classifier

DEFF Research Database (Denmark)

Creixell Mediante, Ester; Haddad, Karim; Song, Wookeun

2015-01-01

A method for sound recognition of coexisting environmental noise sources by applying pattern recognition techniques is developed. The investigated technique could benefit several areas of application, such as noise impact assessment, acoustic pollution mitigation and soundscape characterization...

Optimal Prediction of Moving Sound Source Direction in the Owl.

Directory of Open Access Journals (Sweden)

Weston Cox

2015-07-01

Full Text Available Capturing nature's statistical structure in behavioral responses is at the core of the ability to function adaptively in the environment. Bayesian statistical inference describes how sensory and prior information can be combined optimally to guide behavior. An outstanding open question of how neural coding supports Bayesian inference includes how sensory cues are optimally integrated over time. Here we address what neural response properties allow a neural system to perform Bayesian prediction, i.e., predicting where a source will be in the near future given sensory information and prior assumptions. The work here shows that the population vector decoder will perform Bayesian prediction when the receptive fields of the neurons encode the target dynamics with shifting receptive fields. We test the model using the system that underlies sound localization in barn owls. Neurons in the owl's midbrain show shifting receptive fields for moving sources that are consistent with the predictions of the model. We predict that neural populations can be specialized to represent the statistics of dynamic stimuli to allow for a vector read-out of Bayes-optimal predictions.

A Survey of Sound Source Localization Methods in Wireless Acoustic Sensor Networks

Directory of Open Access Journals (Sweden)

Maximo Cobos

2017-01-01

Full Text Available Wireless acoustic sensor networks (WASNs are formed by a distributed group of acoustic-sensing devices featuring audio playing and recording capabilities. Current mobile computing platforms offer great possibilities for the design of audio-related applications involving acoustic-sensing nodes. In this context, acoustic source localization is one of the application domains that have attracted the most attention of the research community along the last decades. In general terms, the localization of acoustic sources can be achieved by studying energy and temporal and/or directional features from the incoming sound at different microphones and using a suitable model that relates those features with the spatial location of the source (or sources of interest. This paper reviews common approaches for source localization in WASNs that are focused on different types of acoustic features, namely, the energy of the incoming signals, their time of arrival (TOA or time difference of arrival (TDOA, the direction of arrival (DOA, and the steered response power (SRP resulting from combining multiple microphone signals. Additionally, we discuss methods not only aimed at localizing acoustic sources but also designed to locate the nodes themselves in the network. Finally, we discuss current challenges and frontiers in this field.

Sound field separation with cross measurement surfaces.

Directory of Open Access Journals (Sweden)

Jin Mao

Full Text Available With conventional near-field acoustical holography, it is impossible to identify sound pressure when the coherent sound sources are located on the same side of the array. This paper proposes a solution, using cross measurement surfaces to separate the sources based on the equivalent source method. Each equivalent source surface is built in the center of the corresponding original source with a spherical surface. According to the different transfer matrices between equivalent sources and points on holographic surfaces, the weighting of each equivalent source from coherent sources can be obtained. Numerical and experimental studies have been performed to test the method. For the sound pressure including noise after separation in the experiment, the calculation accuracy can be improved by reconstructing the pressure with Tikhonov regularization and the L-curve method. On the whole, a single source can be effectively separated from coherent sources using cross measurement.

Sensitivity to plant modelling uncertainties in optimal feedback control of sound radiation from a panel

DEFF Research Database (Denmark)

Mørkholt, Jakob

1997-01-01

Optimal feedback control of broadband sound radiation from a rectangular baffled panel has been investigated through computer simulations. Special emphasis has been put on the sensitivity of the optimal feedback control to uncertainties in the modelling of the system under control.A model...... in terms of a set of radiation filters modelling the radiation dynamics.Linear quadratic feedback control applied to the panel in order to minimise the radiated sound power has then been simulated. The sensitivity of the model based controller to modelling uncertainties when using feedback from actual...

Research of Control System and Fault Diagnosis of the Sound-absorbing Board Production Line

Directory of Open Access Journals (Sweden)

Yanjun Xiao

2014-08-01

Full Text Available Programmable Logic Controller is the core of the control system of the sound- absorbing board production line and the design of fault diagnosis is an essential modules in the sound- absorbing board production line. The article discourses the application of PLC in the control system of the production line, and designs the methods of grading treatment and prevention of troubles, which makes use of PLC’S logic functions. The method has good expansibility, and has good guidance to the fault diagnosis in other automation equipments.

Abnormal sound detection device

International Nuclear Information System (INIS)

Yamada, Izumi; Matsui, Yuji.

1995-01-01

Only components synchronized with rotation of pumps are sampled from detected acoustic sounds, to judge the presence or absence of abnormality based on the magnitude of the synchronized components. A synchronized component sampling means can remove resonance sounds and other acoustic sounds generated at a synchronously with the rotation based on the knowledge that generated acoustic components in a normal state are a sort of resonance sounds and are not precisely synchronized with the number of rotation. On the other hand, abnormal sounds of a rotating body are often caused by compulsory force accompanying the rotation as a generation source, and the abnormal sounds can be detected by extracting only the rotation-synchronized components. Since components of normal acoustic sounds generated at present are discriminated from the detected sounds, reduction of the abnormal sounds due to a signal processing can be avoided and, as a result, abnormal sound detection sensitivity can be improved. Further, since it is adapted to discriminate the occurrence of the abnormal sound from the actually detected sounds, the other frequency components which are forecast but not generated actually are not removed, so that it is further effective for the improvement of detection sensitivity. (N.H.)

Digital servo control of random sound test excitation. [in reverberant acoustic chamber

Science.gov (United States)

Nakich, R. B. (Inventor)

1974-01-01

A digital servocontrol system for random noise excitation of a test object in a reverberant acoustic chamber employs a plurality of sensors spaced in the sound field to produce signals in separate channels which are decorrelated and averaged. The average signal is divided into a plurality of adjacent frequency bands cyclically sampled by a time division multiplex system, converted into digital form, and compared to a predetermined spectrum value stored in digital form. The results of the comparisons are used to control a time-shared up-down counter to develop gain control signals for the respective frequency bands in the spectrum of random sound energy picked up by the microphones.

Sound propagation in cities

NARCIS (Netherlands)

Salomons, E.; Polinder, H.; Lohman, W.; Zhou, H.; Borst, H.

2009-01-01

A new engineering model for sound propagation in cities is presented. The model is based on numerical and experimental studies of sound propagation between street canyons. Multiple reflections in the source canyon and the receiver canyon are taken into account in an efficient way, while weak

Sound field separation with sound pressure and particle velocity measurements

DEFF Research Database (Denmark)

Fernandez Grande, Efren; Jacobsen, Finn; Leclère, Quentin

2012-01-01

separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure...... and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance......In conventional near-field acoustic holography (NAH) it is not possible to distinguish between sound from the two sides of the array, thus, it is a requirement that all the sources are confined to only one side and radiate into a free field. When this requirement cannot be fulfilled, sound field...

Spike-timing-based computation in sound localization.

Directory of Open Access Journals (Sweden)

Dan F M Goodman

2010-11-01

Full Text Available Spike timing is precise in the auditory system and it has been argued that it conveys information about auditory stimuli, in particular about the location of a sound source. However, beyond simple time differences, the way in which neurons might extract this information is unclear and the potential computational advantages are unknown. The computational difficulty of this task for an animal is to locate the source of an unexpected sound from two monaural signals that are highly dependent on the unknown source signal. In neuron models consisting of spectro-temporal filtering and spiking nonlinearity, we found that the binaural structure induced by spatialized sounds is mapped to synchrony patterns that depend on source location rather than on source signal. Location-specific synchrony patterns would then result in the activation of location-specific assemblies of postsynaptic neurons. We designed a spiking neuron model which exploited this principle to locate a variety of sound sources in a virtual acoustic environment using measured human head-related transfer functions. The model was able to accurately estimate the location of previously unknown sounds in both azimuth and elevation (including front/back discrimination in a known acoustic environment. We found that multiple representations of different acoustic environments could coexist as sets of overlapping neural assemblies which could be associated with spatial locations by Hebbian learning. The model demonstrates the computational relevance of relative spike timing to extract spatial information about sources independently of the source signal.

Source Separation of Heartbeat Sounds for Effective E-Auscultation

Science.gov (United States)

Geethu, R. S.; Krishnakumar, M.; Pramod, K. V.; George, Sudhish N.

2016-03-01

This paper proposes a cost effective solution for improving the effectiveness of e-auscultation. Auscultation is the most difficult skill for a doctor, since it can be acquired only through experience. The heart sound mixtures are captured by placing the four numbers of sensors at appropriate auscultation area in the body. These sound mixtures are separated to its relevant components by a statistical method independent component analysis. The separated heartbeat sounds can be further processed or can be stored for future reference. This idea can be used for making a low cost, easy to use portable instrument which will be beneficial to people living in remote areas and are unable to take the advantage of advanced diagnosis methods.

Recent paleoseismicity record in Prince William Sound, Alaska, USA

Science.gov (United States)

Kuehl, Steven A.; Miller, Eric J.; Marshall, Nicole R.; Dellapenna, Timothy M.

2017-12-01

Sedimentological and geochemical investigation of sediment cores collected in the deep (>400 m) central basin of Prince William Sound, along with geochemical fingerprinting of sediment source areas, are used to identify earthquake-generated sediment gravity flows. Prince William Sound receives sediment from two distinct sources: from offshore (primarily Copper River) through Hinchinbrook Inlet, and from sources within the Sound (primarily Columbia Glacier). These sources are found to have diagnostic elemental ratios indicative of provenance; Copper River Basin sediments were significantly higher in Sr/Pb and Cu/Pb, whereas Prince William Sound sediments were significantly higher in K/Ca and Rb/Sr. Within the past century, sediment gravity flows deposited within the deep central channel of Prince William Sound have robust geochemical (provenance) signatures that can be correlated with known moderate to large earthquakes in the region. Given the thick Holocene sequence in the Sound ( 200 m) and correspondingly high sedimentation rates (>1 cm year-1), this relationship suggests that sediments within the central basin of Prince William Sound may contain an extraordinary high-resolution record of paleoseismicity in the region.

Gestural Control Of Wavefield synthesis

DEFF Research Database (Denmark)

Grani, Francesco; Di Carlo, Diego; Portillo, Jorge Madrid

2016-01-01

We present a report covering our preliminary research on the control of spatial sound sources in wavefield synthesis through gesture based interfaces. After a short general introduction on spatial sound and few basic concepts on wavefield synthesis, we presents a graphical application called sp......AAce which let users to con- trol real-time movements of sound sources by drawing tra- jectories on a screen. The first prototype of this application has been developed bound to WFSCollider, an open-source software based on Supercollider which let users control wavefield synthesis. The spAAce application has...... been im- plemented using Processing, a programming language for sketches and prototypes within the context of visual arts, and communicates with WFSCollider through the Open Sound Control protocol. This application aims to create a new way of interaction for live performance of spatial composition...

Statistics of natural binaural sounds.

Directory of Open Access Journals (Sweden)

Wiktor Młynarski

Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Statistics of natural binaural sounds.

Science.gov (United States)

Młynarski, Wiktor; Jost, Jürgen

2014-01-01

Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Sound Control-Flow Graph Extraction for Java Programs with Exceptions

NARCIS (Netherlands)

Amighi, A.; de Carvalho Gomes, Pedro; Gurov, Dilian; Huisman, Marieke; Eleftherakis, George; Hinchey, Mike; Holcombe, Mike

2012-01-01

We present an algorithm to extract control-flow graphs from Java bytecode, considering exceptional flows. We then establish its correctness: the behavior of the extracted graphs is shown to be a sound over-approximation of the behavior of the original programs. Thus, any temporal safety property

Design of UAV-Embedded Microphone Array System for Sound Source Localization in Outdoor Environments †

Science.gov (United States)

Hoshiba, Kotaro; Washizaki, Kai; Wakabayashi, Mizuho; Ishiki, Takahiro; Bando, Yoshiaki; Gabriel, Daniel; Nakadai, Kazuhiro; Okuno, Hiroshi G.

2017-01-01

In search and rescue activities, unmanned aerial vehicles (UAV) should exploit sound information to compensate for poor visual information. This paper describes the design and implementation of a UAV-embedded microphone array system for sound source localization in outdoor environments. Four critical development problems included water-resistance of the microphone array, efficiency in assembling, reliability of wireless communication, and sufficiency of visualization tools for operators. To solve these problems, we developed a spherical microphone array system (SMAS) consisting of a microphone array, a stable wireless network communication system, and intuitive visualization tools. The performance of SMAS was evaluated with simulated data and a demonstration in the field. Results confirmed that the SMAS provides highly accurate localization, water resistance, prompt assembly, stable wireless communication, and intuitive information for observers and operators. PMID:29099790

The effect of scattering on sound field control with a circular double-layer array of loudspeakers

DEFF Research Database (Denmark)

Chang, Jiho; Jacobsen, Finn

2012-01-01

A recent study has shown that a circular double-layer array of loudspeakers makes it possible to achieve a sound field control that can generate a controlled field inside the array and reduce sound waves propagating outside the array. This is useful if it is desirable not to disturb people outside...... the array or to prevent the effect of reflections from the room. The study assumed free field condition, however in practice a listener will be located inside the array. The listener scatters sound waves, which propagate outward. Consequently, the scattering effect can be expected to degrade the performance...

Heat Transfer by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

Science.gov (United States)

Dreyer, Michael; Fuhrmann, Eckart

The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The topic of this paper is to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat trans-fer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. The paper will deliver correlations for the effective contact angle and the heat transfer coefficient as a function of the relevant dimensionsless parameters as well as physical explanations for the observed behavior. The data will be used

Numerical simulation of aerodynamic sound radiated from a two-dimensional airfoil

OpenAIRE

飯田, 明由; 大田黒, 俊夫; 加藤, 千幸; Akiyoshi, Iida; Toshio, Otaguro; Chisachi, Kato; 日立機研; 日立機研; 東大生研; Mechanical Engineering Research Laboratory, Hitachi Ltd.; Mechanical Engineering Research Laboratory, Hitachi Ltd.; University of Tokyo

2000-01-01

An aerodynamic sound radiated from a two-dimensional airfoil has been computed with the Lighthill-Curle's theory. The predicted sound pressure level is agreement with the measured one. Distribution of vortex sound sources is also estimated based on the correlation between the unsteady vorticity fluctuations and the aerodynamic sound. The distribution of vortex sound source reveals that separated shear layers generate aerodynamic sound. This result is help to understand noise reduction method....

On Distributions of Emission Sources and Speed-of-Sound in Proton-Proton (Proton-Antiproton Collisions

Directory of Open Access Journals (Sweden)

Li-Na Gao

2015-01-01

Full Text Available The revised (three-source Landau hydrodynamic model is used in this paper to study the (pseudorapidity distributions of charged particles produced in proton-proton and proton-antiproton collisions at high energies. The central source is assumed to contribute with a Gaussian function which covers the rapidity distribution region as wide as possible. The target and projectile sources are assumed to emit isotropically particles in their respective rest frames. The model calculations obtained with a Monte Carlo method are fitted to the experimental data over an energy range from 0.2 to 13 TeV. The values of the squared speed-of-sound parameter in different collisions are then extracted from the width of the rapidity distributions.

Sound segregation via embedded repetition is robust to inattention.

Science.gov (United States)

Masutomi, Keiko; Barascud, Nicolas; Kashino, Makio; McDermott, Josh H; Chait, Maria

2016-03-01

The segregation of sound sources from the mixture of sounds that enters the ear is a core capacity of human hearing, but the extent to which this process is dependent on attention remains unclear. This study investigated the effect of attention on the ability to segregate sounds via repetition. We utilized a dual task design in which stimuli to be segregated were presented along with stimuli for a "decoy" task that required continuous monitoring. The task to assess segregation presented a target sound 10 times in a row, each time concurrent with a different distractor sound. McDermott, Wrobleski, and Oxenham (2011) demonstrated that repetition causes the target sound to be segregated from the distractors. Segregation was queried by asking listeners whether a subsequent probe sound was identical to the target. A control task presented similar stimuli but probed discrimination without engaging segregation processes. We present results from 3 different decoy tasks: a visual multiple object tracking task, a rapid serial visual presentation (RSVP) digit encoding task, and a demanding auditory monitoring task. Load was manipulated by using high- and low-demand versions of each decoy task. The data provide converging evidence of a small effect of attention that is nonspecific, in that it affected the segregation and control tasks to a similar extent. In all cases, segregation performance remained high despite the presence of a concurrent, objectively demanding decoy task. The results suggest that repetition-based segregation is robust to inattention. (c) 2016 APA, all rights reserved).

Human Sound Externalization in Reverberant Environments

DEFF Research Database (Denmark)

Catic, Jasmina

In everyday environments, listeners perceive sound sources as externalized. In listening conditions where the spatial cues that are relevant for externalization are not represented correctly, such as when listening through headphones or hearing aids, a degraded perception of externalization may...... occur. In this thesis, the spatial cues that arise from a combined effect of filtering due to the head, torso, and pinna and the acoustic environment were analysed and the impact of such cues for the perception of externalization in different frequency regions was investigated. Distant sound sources...... were simulated via headphones using individualized binaural room impulse responses (BRIRs). An investigation of the influence of spectral content of a sound source on externalization showed that effective externalization cues are present across the entire frequency range. The fluctuation of interaural...

An investigation of the usability of sound recognition for source separation of packaging wastes in reverse vending machines.

Science.gov (United States)

Korucu, M Kemal; Kaplan, Özgür; Büyük, Osman; Güllü, M Kemal

2016-10-01

In this study, we investigate the usability of sound recognition for source separation of packaging wastes in reverse vending machines (RVMs). For this purpose, an experimental setup equipped with a sound recording mechanism was prepared. Packaging waste sounds generated by three physical impacts such as free falling, pneumatic hitting and hydraulic crushing were separately recorded using two different microphones. To classify the waste types and sizes based on sound features of the wastes, a support vector machine (SVM) and a hidden Markov model (HMM) based sound classification systems were developed. In the basic experimental setup in which only free falling impact type was considered, SVM and HMM systems provided 100% classification accuracy for both microphones. In the expanded experimental setup which includes all three impact types, material type classification accuracies were 96.5% for dynamic microphone and 97.7% for condenser microphone. When both the material type and the size of the wastes were classified, the accuracy was 88.6% for the microphones. The modeling studies indicated that hydraulic crushing impact type recordings were very noisy for an effective sound recognition application. In the detailed analysis of the recognition errors, it was observed that most of the errors occurred in the hitting impact type. According to the experimental results, it can be said that the proposed novel approach for the separation of packaging wastes could provide a high classification performance for RVMs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC.

Science.gov (United States)

Keil, Richard; Salemme, Keri; Forrest, Brittany; Neibauer, Jaqui; Logsdon, Miles

2011-11-01

Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600 n g L(-1) on average). Concentrations of xenobiotics were 10-100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound. Published by Elsevier Ltd.

The effect of brain lesions on sound localization in complex acoustic environments.

Science.gov (United States)

Zündorf, Ida C; Karnath, Hans-Otto; Lewald, Jörg

2014-05-01

Localizing sound sources of interest in cluttered acoustic environments--as in the 'cocktail-party' situation--is one of the most demanding challenges to the human auditory system in everyday life. In this study, stroke patients' ability to localize acoustic targets in a single-source and in a multi-source setup in the free sound field were directly compared. Subsequent voxel-based lesion-behaviour mapping analyses were computed to uncover the brain areas associated with a deficit in localization in the presence of multiple distracter sound sources rather than localization of individually presented sound sources. Analyses revealed a fundamental role of the right planum temporale in this task. The results from the left hemisphere were less straightforward, but suggested an involvement of inferior frontal and pre- and postcentral areas. These areas appear to be particularly involved in the spectrotemporal analyses crucial for effective segregation of multiple sound streams from various locations, beyond the currently known network for localization of isolated sound sources in otherwise silent surroundings.

Digital servo control of random sound fields

Science.gov (United States)

Nakich, R. B.

1973-01-01

It is necessary to place number of sensors at different positions in sound field to determine actual sound intensities to which test object is subjected. It is possible to determine whether specification is being met adequately or exceeded. Since excitation is of random nature, signals are essentially coherent and it is impossible to obtain true average.

Sound Zones

DEFF Research Database (Denmark)

Møller, Martin Bo; Olsen, Martin

2017-01-01

Sound zones, i.e. spatially confined regions of individual audio content, can be created by appropriate filtering of the desired audio signals reproduced by an array of loudspeakers. The challenge of designing filters for sound zones is twofold: First, the filtered responses should generate...... an acoustic separation between the control regions. Secondly, the pre- and post-ringing as well as spectral deterioration introduced by the filters should be minimized. The tradeoff between acoustic separation and filter ringing is the focus of this paper. A weighted L2-norm penalty is introduced in the sound...

Car audio using DSP for active sound control. DSP ni yoru active seigyo wo mochiita audio

Energy Technology Data Exchange (ETDEWEB)

Yamada, K.; Asano, S.; Furukawa, N. (Mitsubishi Motor Corp., Tokyo (Japan))

1993-06-01

In the automobile cabin, there are some unique problems which spoil the quality of sound reproduction from audio equipment, such as the narrow space and/or the background noise. The audio signal processing by using DSP (digital signal processor) makes enable a solution to these problems. A car audio with a high amenity has been successfully made by the active sound control using DSP. The DSP consists of an adder, coefficient multiplier, delay unit, and connections. For the actual processing by DSP, are used functions, such as sound field correction, response and processing of noises during driving, surround reproduction, graphic equalizer processing, etc. High effectiveness of the method was confirmed through the actual driving evaluation test. The present paper describes the actual method of sound control technology using DSP. Especially, the dynamic processing of the noise during driving is discussed in detail. 1 ref., 12 figs., 1 tab.

Common sole larvae survive high levels of pile-driving sound in controlled exposure experiments.

Directory of Open Access Journals (Sweden)

Loes J Bolle

Full Text Available In view of the rapid extension of offshore wind farms, there is an urgent need to improve our knowledge on possible adverse effects of underwater sound generated by pile-driving. Mortality and injuries have been observed in fish exposed to loud impulse sounds, but knowledge on the sound levels at which (sub-lethal effects occur is limited for juvenile and adult fish, and virtually non-existent for fish eggs and larvae. A device was developed in which fish larvae can be exposed to underwater sound. It consists of a rigid-walled cylindrical chamber driven by an electro-dynamical sound projector. Samples of up to 100 larvae can be exposed simultaneously to a homogeneously distributed sound pressure and particle velocity field. Recorded pile-driving sounds could be reproduced accurately in the frequency range between 50 and 1000 Hz, at zero to peak pressure levels up to 210 dB re 1µPa(2 (zero to peak pressures up to 32 kPa and single pulse sound exposure levels up to 186 dB re 1µPa(2s. The device was used to examine lethal effects of sound exposure in common sole (Solea solea larvae. Different developmental stages were exposed to various levels and durations of pile-driving sound. The highest cumulative sound exposure level applied was 206 dB re 1µPa(2s, which corresponds to 100 strikes at a distance of 100 m from a typical North Sea pile-driving site. The results showed no statistically significant differences in mortality between exposure and control groups at sound exposure levels which were well above the US interim criteria for non-auditory tissue damage in fish. Although our findings cannot be extrapolated to fish larvae in general, as interspecific differences in vulnerability to sound exposure may occur, they do indicate that previous assumptions and criteria may need to be revised.

Eluding the Physical Constraints in a Nonlinear Interaction Sound Synthesis Model for Gesture Guidance

Directory of Open Access Journals (Sweden)

Etienne Thoret

2016-06-01

Full Text Available In this paper, a flexible control strategy for a synthesis model dedicated to nonlinear friction phenomena is proposed. This model enables to synthesize different types of sound sources, such as creaky doors, singing glasses, squeaking wet plates or bowed strings. Based on the perceptual stance that a sound is perceived as the result of an action on an object we propose a genuine source/filter synthesis approach that enables to elude physical constraints induced by the coupling between the interacting objects. This approach makes it possible to independently control and freely combine the action and the object. Different implementations and applications related to computer animation, gesture learning for rehabilitation and expert gestures are presented at the end of this paper.

Effort variation regularization in sound field reproduction

DEFF Research Database (Denmark)

Stefanakis, Nick; Jacobsen, Finn; Sarris, Ioannis

2010-01-01

In this paper, active control is used in order to reproduce a given sound field in an extended spatial region. A method is proposed which minimizes the reproduction error at a number of control positions with the reproduction sources holding a certain relation within their complex strengths......), and adaptive wave field synthesis (AWFS), both under free-field conditions and in reverberant rooms. It is shown that effort variation regularization overcomes the problems associated with small spaces and with a low ratio of direct to reverberant energy, improving thus the reproduction accuracy...

Waveform analysis of sound

CERN Document Server

Tohyama, Mikio

2015-01-01

What is this sound? What does that sound indicate? These are two questions frequently heard in daily conversation. Sound results from the vibrations of elastic media and in daily life provides informative signals of events happening in the surrounding environment. In interpreting auditory sensations, the human ear seems particularly good at extracting the signal signatures from sound waves. Although exploring auditory processing schemes may be beyond our capabilities, source signature analysis is a very attractive area in which signal-processing schemes can be developed using mathematical expressions. This book is inspired by such processing schemes and is oriented to signature analysis of waveforms. Most of the examples in the book are taken from data of sound and vibrations; however, the methods and theories are mostly formulated using mathematical expressions rather than by acoustical interpretation. This book might therefore be attractive and informative for scientists, engineers, researchers, and graduat...

Lexical and perceptual grounding of a sound ontology

NARCIS (Netherlands)

Lobanova, Anna; Spenader, Jennifer; Valkenier, Bea; Matousek,; Mautner, P

2007-01-01

Sound ontologies need to incorporate source unidentifiable sounds in an adequate and consistent manner. Computational lexical resources like WordNet have either inserted these descriptions into conceptual categories, or make no attempt to organize the terms for these sounds. This work attempts to

Physics of thermo-acoustic sound generation

Science.gov (United States)

Daschewski, M.; Boehm, R.; Prager, J.; Kreutzbruck, M.; Harrer, A.

2013-09-01

We present a generalized analytical model of thermo-acoustic sound generation based on the analysis of thermally induced energy density fluctuations and their propagation into the adjacent matter. The model provides exact analytical prediction of the sound pressure generated in fluids and solids; consequently, it can be applied to arbitrary thermal power sources such as thermophones, plasma firings, laser beams, and chemical reactions. Unlike existing approaches, our description also includes acoustic near-field effects and sound-field attenuation. Analytical results are compared with measurements of sound pressures generated by thermo-acoustic transducers in air for frequencies up to 1 MHz. The tested transducers consist of titanium and indium tin oxide coatings on quartz glass and polycarbonate substrates. The model reveals that thermo-acoustic efficiency increases linearly with the supplied thermal power and quadratically with thermal excitation frequency. Comparison of the efficiency of our thermo-acoustic transducers with those of piezoelectric-based airborne ultrasound transducers using impulse excitation showed comparable sound pressure values. The present results show that thermo-acoustic transducers can be applied as broadband, non-resonant, high-performance ultrasound sources.

Hybrid Active/Passive Control of Sound Radiation from Panels with Constrained Layer Damping and Model Predictive Feedback Control

Science.gov (United States)

Cabell, Randolph H.; Gibbs, Gary P.

2000-01-01

There has been considerable interest over the past several years in applying feedback control methods to problems of structural acoustics. One problem of particular interest is the control of sound radiation from aircraft panels excited on one side by a turbulent boundary layer (TBL). TBL excitation appears as many uncorrelated sources acting on the panel, which makes it difficult to find a single reference signal that is coherent with the excitation. Feedback methods have no need for a reference signal, and are thus suited to this problem. Some important considerations for the structural acoustics problem include the fact that the required controller bandwidth can easily extend to several hundred Hertz, so a digital controller would have to operate at a few kilohertz. In addition, aircraft panel structures have a reasonably high modal density over this frequency range. A model based controller must therefore handle the modally dense system, or have some way to reduce the bandwidth of the problem. Further complicating the problem is the fact that the stiffness and dynamic properties of an aircraft panel can vary considerably during flight due to altitude changes resulting in significant resonant frequency shifts. These considerations make the tradeoff between robustness to changes in the system being controlled and controller performance especially important. Recent papers concerning the design and implementation of robust controllers for structural acoustic problems highlight the need to consider both performance and robustness when designing the controller. While robust control methods such as H1 can be used to balance performance and robustness, their implementation is not easy and requires assumptions about the types of uncertainties in the plant being controlled. Achieving a useful controller design may require many tradeoff studies of different types of parametric uncertainties in the system. Another approach to achieving robustness to plant changes is to

Effects of Natural Sounds on Pain: A Randomized Controlled Trial with Patients Receiving Mechanical Ventilation Support.

Science.gov (United States)

Saadatmand, Vahid; Rejeh, Nahid; Heravi-Karimooi, Majideh; Tadrisi, Sayed Davood; Vaismoradi, Mojtaba; Jordan, Sue

2015-08-01

Nonpharmacologic pain management in patients receiving mechanical ventilation support in critical care units is under investigated. Natural sounds may help reduce the potentially harmful effects of anxiety and pain in hospitalized patients. The aim of this study was to examine the effect of pleasant, natural sounds on self-reported pain in patients receiving mechanical ventilation support, using a pragmatic parallel-arm, randomized controlled trial. The study was conducted in a general adult intensive care unit of a high-turnover teaching hospital, in Tehran, Iran. Between October 2011 and June 2012, we recruited 60 patients receiving mechanical ventilation support to the intervention (n = 30) and control arms (n = 30) of a pragmatic parallel-group, randomized controlled trial. Participants in both arms wore headphones for 90 minutes. Those in the intervention arm heard pleasant, natural sounds, whereas those in the control arm heard nothing. Outcome measures included the self-reported visual analog scale for pain at baseline; 30, 60, and 90 minutes into the intervention; and 30 minutes post-intervention. All patients approached agreed to participate. The trial arms were similar at baseline. Pain scores in the intervention arm fell and were significantly lower than in the control arm at each time point (p natural sounds via headphones is a simple, safe, nonpharmacologic nursing intervention that may be used to allay pain for up to 120 minutes in patients receiving mechanical ventilation support. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Sound response of superheated drop bubble detectors to neutrons

International Nuclear Information System (INIS)

Gao Size; Chen Zhe; Liu Chao; Ni Bangfa; Zhang Guiying; Zhao Changfa; Xiao Caijin; Liu Cunxiong; Nie Peng; Guan Yongjing

2012-01-01

The sound response of the bubble detectors to neutrons by using 252 Cf neutron source was described. Sound signals were filtered by sound card and PC. The short-time signal energy. FFT spectrum, power spectrum, and decay time constant were got to determine the authenticity of sound signal for bubbles. (authors)

Visualizing Sound Directivity via Smartphone Sensors

OpenAIRE

Hawley, Scott H.; McClain Jr, Robert E.

2017-01-01

We present a fast, simple method for automated data acquisition and visualization of sound directivity, made convenient and accessible via a smartphone app, "Polar Pattern Plotter." The app synchronizes measurements of sound volume with the phone's angular orientation obtained from either compass, gyroscope or accelerometer sensors and produces a graph and exportable data file. It is generalizable to various sound sources and receivers via the use of an input-jack-adaptor to supplant the smar...

Validating a perceptual distraction model in a personal two-zone sound system

DEFF Research Database (Denmark)

Rämö, Jussi; Christensen, Lasse; Bech, Søren

2017-01-01

This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli...... using a simple loudspeaker setup, consisting of only two loudspeakers, one for the target sound source and the other for the interfering sound source. Recently, the model was successfully validated in a complex personal sound-zone system with speech-on-music stimuli. Second round of validations were...... conducted by physically altering the sound-zone system and running a set of new listening experiments utilizing two sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. Preliminary results show...

Universal mechanisms of sound production and control in birds and mammals

DEFF Research Database (Denmark)

Elemans, Coen; Rasmussen, Jeppe Have; Herbst, Christian T.

2015-01-01

As animals vocalize, their vocal organ transforms motor commands into vocalizations for social communication. In birds, the physical mechanisms by which vocalizations are produced and controlled remain unresolved because of the extreme difficulty in obtaining in vivo measurements. Here, we...... learning and is common to MEAD sound production across birds and mammals, including humans....

Interactive physically-based sound simulation

Science.gov (United States)

Raghuvanshi, Nikunj

The realization of interactive, immersive virtual worlds requires the ability to present a realistic audio experience that convincingly compliments their visual rendering. Physical simulation is a natural way to achieve such realism, enabling deeply immersive virtual worlds. However, physically-based sound simulation is very computationally expensive owing to the high-frequency, transient oscillations underlying audible sounds. The increasing computational power of desktop computers has served to reduce the gap between required and available computation, and it has become possible to bridge this gap further by using a combination of algorithmic improvements that exploit the physical, as well as perceptual properties of audible sounds. My thesis is a step in this direction. My dissertation concentrates on developing real-time techniques for both sub-problems of sound simulation: synthesis and propagation. Sound synthesis is concerned with generating the sounds produced by objects due to elastic surface vibrations upon interaction with the environment, such as collisions. I present novel techniques that exploit human auditory perception to simulate scenes with hundreds of sounding objects undergoing impact and rolling in real time. Sound propagation is the complementary problem of modeling the high-order scattering and diffraction of sound in an environment as it travels from source to listener. I discuss my work on a novel numerical acoustic simulator (ARD) that is hundred times faster and consumes ten times less memory than a high-accuracy finite-difference technique, allowing acoustic simulations on previously-intractable spaces, such as a cathedral, on a desktop computer. Lastly, I present my work on interactive sound propagation that leverages my ARD simulator to render the acoustics of arbitrary static scenes for multiple moving sources and listener in real time, while accounting for scene-dependent effects such as low-pass filtering and smooth attenuation

Sound Surfing Network (SSN): Mobile Phone-based Sound Spatialization with Audience Collaboration

OpenAIRE

Park, Saebyul; Ban, Seonghoon; Hong, Dae Ryong; Yeo, Woon Seung

2013-01-01

SSN (Sound Surfing Network) is a performance system that provides a new musicalexperience by incorporating mobile phone-based spatial sound control tocollaborative music performance. SSN enables both the performer and theaudience to manipulate the spatial distribution of sound using the smartphonesof the audience as distributed speaker system. Proposing a new perspective tothe social aspect music appreciation, SSN will provide a new possibility tomobile music performances in the context of in...

Costs of suppressing emotional sound and countereffects of a mindfulness induction: an experimental analog of tinnitus impact.

Directory of Open Access Journals (Sweden)

Hugo Hesser

Full Text Available Tinnitus is the experience of sounds without an appropriate external auditory source. These auditory sensations are intertwined with emotional and attentional processing. Drawing on theories of mental control, we predicted that suppressing an affectively negative sound mimicking the psychoacoustic features of tinnitus would result in decreased persistence in a mentally challenging task (mental arithmetic that required participants to ignore the same sound, but that receiving a mindfulness exercise would reduce this effect. Normal hearing participants (N = 119 were instructed to suppress an affectively negative sound under cognitive load or were given no such instructions. Next, participants received either a mindfulness induction or an attention control task. Finally, all participants worked with mental arithmetic while exposed to the same sound. The length of time participants could persist in the second task served as the dependent variable. As hypothesized, results indicated that an auditory suppression rationale reduced time of persistence relative to no such rationale, and that a mindfulness induction counteracted this detrimental effect. The study may offer new insights into the mechanisms involved in the development of tinnitus interference. Implications are also discussed in the broader context of attention control strategies and the effects of emotional sound on task performance. The ironic processes of mental control may have an analog in the experience of sounds.

A review of research progress in air-to-water sound transmission

International Nuclear Information System (INIS)

Peng Zhao-Hui; Zhang Ling-Shan

2016-01-01

International and domestic research progress in theory and experiment and applications of the air-to-water sound transmission are presented in this paper. Four classical numerical methods of calculating the underwater sound field generated by an airborne source, i.e., the ray theory, the wave solution, the normal-mode theory and the wavenumber integration approach, are introduced. Effects of two special conditions, i.e., the moving airborne source or medium and the rough air-water interface, on the air-to-water sound transmission are reviewed. In experimental studies, the depth and range distributions of the underwater sound field created by different kinds of airborne sources in near-field and far-field, the longitudinal horizontal correlation of underwater sound field and application methods for inverse problems are reviewed. (special topic)

Amplitude and frequency modulation control of sound production in a mechanical model of the avian syrinx

DEFF Research Database (Denmark)

Elemans, Coen; Muller, Mees; Larsen, Ole Næsbye

2009-01-01

membrane and generate a wide variety of ‘syllables' with simple sweeps of the control parameters. We show that the membrane exhibits high frequency, self-sustained oscillations in the audio range (>600 Hz fundamental frequency) using laser Doppler vibrometry, and systematically explore the conditions...... for sound production of the model in its control space. The fundamental frequency of the sound increases with tension in three membranes with different stiffness and mass. The lowerbound fundamental frequency increases with membrane mass. The membrane vibrations are strongly coupled to the resonance...

Sources of underwater sound and their characterisation (abstract)

NARCIS (Netherlands)

Ainslie, M.A.; Jong, C.A.F. de

2013-01-01

After centuries of speculation, punctuated by occasional theoretical or experimental advances, the first intensive research into underwater sound took place 100 years ago, applied initially to provide advance warning of icebergs after the loss of RMS Titanic in 1912, and later to counter the U-boat

Theoretical and experimental study on active sound transmission control based on single structural mode actuation using point force actuators.

Science.gov (United States)

Sanada, Akira; Tanaka, Nobuo

2012-08-01

This study deals with the feedforward active control of sound transmission through a simply supported rectangular panel using vibration actuators. The control effect largely depends on the excitation method, including the number and locations of actuators. In order to obtain a large control effect at low frequencies over a wide frequency, an active transmission control method based on single structural mode actuation is proposed. Then, with the goal of examining the feasibility of the proposed method, the (1, 3) mode is selected as the target mode and a modal actuation method in combination with six point force actuators is considered. Assuming that a single input single output feedforward control is used, sound transmission in the case minimizing the transmitted sound power is calculated for some actuation methods. Simulation results showed that the (1, 3) modal actuation is globally effective at reducing the sound transmission by more than 10 dB in the low-frequency range for both normal and oblique incidences. Finally, experimental results also showed that a large reduction could be achieved in the low-frequency range, which proves the validity and feasibility of the proposed method.

Sound field reproduction as an equivalent acoustical scattering problem.

Science.gov (United States)

Fazi, Filippo Maria; Nelson, Philip A

2013-11-01

Given a continuous distribution of acoustic sources, the determination of the source strength that ensures the synthesis of a desired sound field is shown to be identical to the solution of an equivalent acoustic scattering problem. The paper begins with the presentation of the general theory that underpins sound field reproduction with secondary sources continuously arranged on the boundary of the reproduction region. The process of reproduction by a continuous source distribution is modeled by means of an integral operator (the single layer potential). It is then shown how the solution of the sound reproduction problem corresponds to that of an equivalent scattering problem. Analytical solutions are computed for two specific instances of this problem, involving, respectively, the use of a secondary source distribution in spherical and planar geometries. The results are shown to be the same as those obtained with analyses based on High Order Ambisonics and Wave Field Synthesis, respectively, thus bringing to light a fundamental analogy between these two methods of sound reproduction. Finally, it is shown how the physical optics (Kirchhoff) approximation enables the derivation of a high-frequency simplification for the problem under consideration, this in turn being related to the secondary source selection criterion reported in the literature on Wave Field Synthesis.

Compressing Sensing Based Source Localization for Controlled Acoustic Signals Using Distributed Microphone Arrays

Directory of Open Access Journals (Sweden)

Wei Ke

2017-01-01

Full Text Available In order to enhance the accuracy of sound source localization in noisy and reverberant environments, this paper proposes an adaptive sound source localization method based on distributed microphone arrays. Since sound sources lie at a few points in the discrete spatial domain, our method can exploit this inherent sparsity to convert the localization problem into a sparse recovery problem based on the compressive sensing (CS theory. In this method, a two-step discrete cosine transform- (DCT- based feature extraction approach is utilized to cover both short-time and long-time properties of acoustic signals and reduce the dimensions of the sparse model. In addition, an online dictionary learning (DL method is used to adjust the dictionary for matching the changes of audio signals, and then the sparse solution could better represent location estimations. Moreover, we propose an improved block-sparse reconstruction algorithm using approximate l0 norm minimization to enhance reconstruction performance for sparse signals in low signal-noise ratio (SNR conditions. The effectiveness of the proposed scheme is demonstrated by simulation results and experimental results where substantial improvement for localization performance can be obtained in the noisy and reverberant conditions.

A seafloor electromagnetic receiver for marine magnetotellurics and marine controlled-source electromagnetic sounding

Science.gov (United States)

Chen, Kai; Wei, Wen-Bo; Deng, Ming; Wu, Zhong-Liang; Yu, Gang

2015-09-01

In planning and executing marine controlled-source electromagnetic methods, seafloor electromagnetic receivers must overcome the problems of noise, clock drift, and power consumption. To design a receiver that performs well and overcomes the abovementioned problems, we performed forward modeling of the E-field abnormal response and established the receiver's characteristics. We describe the design optimization and the properties of each component, that is, low-noise induction coil sensor, low-noise Ag/AgCl electrode, low-noise chopper amplifier, digital temperature-compensated crystal oscillator module, acoustic telemetry modem, and burn wire system. Finally, we discuss the results of onshore and offshore field tests to show the effectiveness of the developed seafloor electromagnetic receiver and its performance: typical E-field noise of 0.12 nV/m/rt(Hz) at 0.5 Hz, dynamic range higher than 120 dB, clock drift lower than 1 ms/day, and continuous operation of at least 21 days.

Reconstruction of sound fields with a spherical microphone array

DEFF Research Database (Denmark)

Fernandez Grande, Efren; Walton, Tim

2014-01-01

waves traveling in any direction. In particular, rigid sphere microphone arrays are robust, and have the favorable property that the scattering introduced by the array can be compensated for - making the array virtually transparent. This study examines a recently proposed sound field reconstruction...... method based on a point source expansion, i.e. equivalent source method, using a rigid spherical array. The study examines the capability of the method to distinguish between sound waves arriving from different directions (i.e., as a sound field separation method). This is representative of the potential...

Sources and levels of ambient ocean sound near the Antarctic Peninsula.

Directory of Open Access Journals (Sweden)

Robert P Dziak

Full Text Available Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus and fin (B. physalus whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns, likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.

Original sound compositions reduce anxiety in emergency department patients: a randomised controlled trial.

Science.gov (United States)

Weiland, Tracey J; Jelinek, George A; Macarow, Keely E; Samartzis, Philip; Brown, David M; Grierson, Elizabeth M; Winter, Craig

2011-12-19

To determine whether emergency department (ED) patients' self-rated levels of anxiety are affected by exposure to purpose-designed music or sound compositions with and without the audio frequencies of embedded binaural beat. Randomised controlled trial in an ED between 1 February 2010 and 14 April 2010 among a convenience sample of adult patients who were rated as category 3 on the Australasian Triage Scale. All interventions involved listening to soundtracks of 20 minutes' duration that were purpose-designed by composers and sound-recording artists. Participants were allocated at random to one of five groups: headphones and iPod only, no soundtrack (control group); reconstructed ambient noise simulating an ED but free of clear verbalisations; electroacoustic musical composition; composed non-musical soundtracks derived from audio field recordings obtained from natural and constructed settings; sound composition of audio field recordings with embedded binaural beat. All soundtracks were presented on an iPod through headphones. Patients and researchers were blinded to allocation until interventions were administered. State-trait anxiety was self-assessed before the intervention and state anxiety was self-assessed again 20 minutes after the provision of the soundtrack. Spielberger State-Trait Anxiety Inventory. Of 291 patients assessed for eligibility, 170 patients completed the pre-intervention anxiety self-assessment and 169 completed the post-intervention assessment. Significant decreases (all P beats (43; 37) when compared with those allocated to receive simulated ED ambient noise (40; 41) or headphones only (44; 44). In moderately anxious ED patients, state anxiety was reduced by 10%-15% following exposure to purpose-designed sound interventions. Australian New Zealand Clinical Trials Registry ACTRN 12608000444381.

Analysis, Synthesis, and Perception of Musical Sounds The Sound of Music

CERN Document Server

Beauchamp, James W

2007-01-01

Analysis, Synthesis, and Perception of Musical Sounds contains a detailed treatment of basic methods for analysis and synthesis of musical sounds, including the phase vocoder method, the McAulay-Quatieri frequency-tracking method, the constant-Q transform, and methods for pitch tracking with several examples shown. Various aspects of musical sound spectra such as spectral envelope, spectral centroid, spectral flux, and spectral irregularity are defined and discussed. One chapter is devoted to the control and synthesis of spectral envelopes. Two advanced methods of analysis/synthesis are given: "Sines Plus Transients Plus Noise" and "Spectrotemporal Reassignment" are covered. Methods for timbre morphing are given. The last two chapters discuss the perception of musical sounds based on discrimination and multidimensional scaling timbre models.

Photoacoustic Sounds from Meteors.

Energy Technology Data Exchange (ETDEWEB)

Spalding, Richard E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tencer, John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sweatt, William C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hogan, Roy E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Spurny, Pavel [Academy of Sciences of the Czech Republic (ASCR), Prague (Czech Republic)

2015-03-01

High-speed photometric observations of meteor fireballs have shown that they often produce high-amplitude light oscillations with frequency components in the kHz range, and in some cases exhibit strong millisecond flares. We built a light source with similar characteristics and illuminated various materials in the laboratory, generating audible sounds. Models suggest that light oscillations and pulses can radiatively heat dielectric materials, which in turn conductively heats the surrounding air on millisecond timescales. The sound waves can be heard if the illuminated material is sufficiently close to the observer’s ears. The mechanism described herein may explain many reports of meteors that appear to be audible while they are concurrently visible in the sky and too far away for sound to have propagated to the observer. This photoacoustic (PA) explanation provides an alternative to electrophonic (EP) sounds hypothesized to arise from electromagnetic coupling of plasma oscillation in the meteor wake to natural antennas in the vicinity of an observer.

Anticipated Effectiveness of Active Noise Control in Propeller Aircraft Interiors as Determined by Sound Quality Tests

Science.gov (United States)

Powell, Clemans A.; Sullivan, Brenda M.

2004-01-01

Two experiments were conducted, using sound quality engineering practices, to determine the subjective effectiveness of hypothetical active noise control systems in a range of propeller aircraft. The two tests differed by the type of judgments made by the subjects: pair comparisons in the first test and numerical category scaling in the second. Although the results of the two tests were in general agreement that the hypothetical active control measures improved the interior noise environments, the pair comparison method appears to be more sensitive to subtle changes in the characteristics of the sounds which are related to passenger preference.

Sound Synthesis and Evaluation of Interactive Footsteps and Environmental Sounds Rendering for Virtual Reality Applications

DEFF Research Database (Denmark)

Nordahl, Rolf; Turchet, Luca; Serafin, Stefania

2011-01-01

We propose a system that affords real-time sound synthesis of footsteps on different materials. The system is based on microphones, which detect real footstep sounds from subjects, from which the ground reaction force (GRF) is estimated. Such GRF is used to control a sound synthesis engine based ...... a soundscape significantly improves the recognition of the simulated environment....

Sustained Magnetic Responses in Temporal Cortex Reflect Instantaneous Significance of Approaching and Receding Sounds.

Directory of Open Access Journals (Sweden)

Dominik R Bach

Full Text Available Rising sound intensity often signals an approaching sound source and can serve as a powerful warning cue, eliciting phasic attention, perception biases and emotional responses. How the evaluation of approaching sounds unfolds over time remains elusive. Here, we capitalised on the temporal resolution of magnetoencephalograpy (MEG to investigate in humans a dynamic encoding of perceiving approaching and receding sounds. We compared magnetic responses to intensity envelopes of complex sounds to those of white noise sounds, in which intensity change is not perceived as approaching. Sustained magnetic fields over temporal sensors tracked intensity change in complex sounds in an approximately linear fashion, an effect not seen for intensity change in white noise sounds, or for overall intensity. Hence, these fields are likely to track approach/recession, but not the apparent (instantaneous distance of the sound source, or its intensity as such. As a likely source of this activity, the bilateral inferior temporal gyrus and right temporo-parietal junction emerged. Our results indicate that discrete temporal cortical areas parametrically encode behavioural significance in moving sound sources where the signal unfolded in a manner reminiscent of evidence accumulation. This may help an understanding of how acoustic percepts are evaluated as behaviourally relevant, where our results highlight a crucial role of cortical areas.

Sperm whales reduce foraging effort during exposure to 1-2 kHz sonar and killer whale sounds.

Science.gov (United States)

Isojunno, Saana; Cure, Charlotte; Kvadsheim, Petter Helgevold; Lam, Frans-Peter Alexander; Tyack, Peter Lloyd; Wensveen, Paul Jacobus; Miller, Patrick James O'Malley

2016-01-01

The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kHz, source level 214 dB re 1 µPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records). Time spent in foraging states and the probability of prey capture attempts were reduced during these two types of exposures with little change in overall locomotion activity, suggesting an effect on energy intake with no immediate compensation. Whales switched to the active non-foraging state over received sound pressure levels of 131-165 dB re 1 µPa during LFAS exposure. In contrast, no changes in foraging behavior were detected in response to experimental negative controls (no-sonar ship approach or noise control playback) or to experimental medium-frequency active sonar exposures (MFAS; 6-7 kHz, source level 199 re 1 µPa m, received sound pressure level [SPL] = 73-158 dB re 1 µPa). Similarly, there was no reduction in foraging effort for three whales exposed to incidental, unidentified 4.7-5.1 kHz sonar signals received at lower levels (SPL = 89-133 dB re 1 µPa). These results demonstrate that similar to predation risk, exposure to sonar can affect functional behaviors, and indicate that increased perception of risk with higher source level or lower frequency may modulate how sperm whales respond to anthropogenic sound.

Sound synthesis and evaluation of interactive footsteps and environmental sounds rendering for virtual reality applications.

Science.gov (United States)

Nordahl, Rolf; Turchet, Luca; Serafin, Stefania

2011-09-01

We propose a system that affords real-time sound synthesis of footsteps on different materials. The system is based on microphones, which detect real footstep sounds from subjects, from which the ground reaction force (GRF) is estimated. Such GRF is used to control a sound synthesis engine based on physical models. Two experiments were conducted. In the first experiment, the ability of subjects to recognize the surface they were exposed to was assessed. In the second experiment, the sound synthesis engine was enhanced with environmental sounds. Results show that, in some conditions, adding a soundscape significantly improves the recognition of the simulated environment.

Integrated Human Factors Design Guidelines for Sound Interface

International Nuclear Information System (INIS)

Lee, Jung Woon; Lee, Yong Hee; Oh, In Seok; Lee, Hyun Chul; Cha, Woo Chang

2004-05-01

Digital MMI, such as CRT, LCD etc., has been used increasingly in the design of main control room of the Korean standard nuclear power plants following the YGN units 3 and 4. The utilization of digital MMI may introduce various kind of sound interface into the control room design. In this project, for five top-level guideline items, including Sound Formats, Alarms, Sound Controls, Communications, and Environments, a total of 147 detail guidelines were developed and a database system for these guidelines was developed. The integrated human factors design guidelines for sound interface and the database system developed in this project will be useful for the design of sound interface of digital MMI in Korean NPPs

Integrated Human Factors Design Guidelines for Sound Interface

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Woon; Lee, Yong Hee; Oh, In Seok; Lee, Hyun Chul [KAERI, Daejeon (Korea, Republic of); Cha, Woo Chang [Kumoh National Univ. of Technology, Gumi (Korea, Republic of)

2004-05-15

Digital MMI, such as CRT, LCD etc., has been used increasingly in the design of main control room of the Korean standard nuclear power plants following the YGN units 3 and 4. The utilization of digital MMI may introduce various kind of sound interface into the control room design. In this project, for five top-level guideline items, including Sound Formats, Alarms, Sound Controls, Communications, and Environments, a total of 147 detail guidelines were developed and a database system for these guidelines was developed. The integrated human factors design guidelines for sound interface and the database system developed in this project will be useful for the design of sound interface of digital MMI in Korean NPPs.

Loudness estimation of simultaneous sources using beamforming

DEFF Research Database (Denmark)

Song, Woo-keun; Ellermeier, Wolfgang; Minnaar, Pauli

2006-01-01

An algorithm is proposed for estimating the loudness of several simultaneous sound sources by means of microphone-array beamforming. The algorithm is derived from two listening experiments in which the loudness of two simultaneous sounds (narrow-band noises with 1-kHz and 3.15-kHz center...... frequencies) was matched to a single sound (2-kHz narrow-band noise). The simultaneous sounds were presented from either one sound source or two spatially separated sources, whereas the single sound was presented from the frontal direction. The results indicate that overall loudness can be calculated...... by summing the loudnesses of the individual sources according to a simple psychophysical relationship....

When Distance Matters: Perceptual Bias and Behavioral Response for Approaching Sounds in Peripersonal and Extrapersonal Space

NARCIS (Netherlands)

Camponogara, I.; Komeilipoor, N.; Cesari, P.

2015-01-01

Studies on sound perception show a tendency to overestimate the distance of an approaching sound source, leading to a faster reaction time compared to a receding sound source. Nevertheless, it is unclear whether motor preparation and execution change according to the perceived sound direction and

By the sound of it. An ERP investigation of human action sound processing in 7-month-old infants

Directory of Open Access Journals (Sweden)

Elena Geangu

2015-04-01

Full Text Available Recent evidence suggests that human adults perceive human action sounds as a distinct category from human vocalizations, environmental, and mechanical sounds, activating different neural networks (Engel et al., 2009; Lewis et al., 2011. Yet, little is known about the development of such specialization. Using event-related potentials (ERP, this study investigated neural correlates of 7-month-olds’ processing of human action (HA sounds in comparison to human vocalizations (HV, environmental (ENV, and mechanical (MEC sounds. Relative to the other categories, HA sounds led to increased positive amplitudes between 470 and 570 ms post-stimulus onset at left anterior temporal locations, while HV led to increased negative amplitudes at the more posterior temporal locations in both hemispheres. Collectively, human produced sounds (HA + HV led to significantly different response profiles compared to non-living sound sources (ENV + MEC at parietal and frontal locations in both hemispheres. Overall, by 7 months of age human action sounds are being differentially processed in the brain, consistent with a dichotomy for processing living versus non-living things. This provides novel evidence regarding the typical categorical processing of socially relevant sounds.

Arrangements of a pair of loudspeakers for sound field control with double-layer arrays

DEFF Research Database (Denmark)

Chang, Jiho; Agerkvist, Finn T.; Olsen, Martin

2013-01-01

Recent studies have attempted to control sound fields, and also to reduce room reflections with a circular or spherical array of loudspeakers. One of the attempts was to suppress sound waves propagating to the walls outside the array with a circular double-layer array of loudspeakers. The double-layer...... array represents a set of a monopole and a dipole in the Kirchhoff-Helmholtz integral equation, and thus the distance between these layers should be short compared with the wavelength. In practice, however, this condition is occasionally hard to satisfy because of the sizes of loudspeaker cabinets...

Acoustic analysis of trill sounds.

Science.gov (United States)

Dhananjaya, N; Yegnanarayana, B; Bhaskararao, Peri

2012-04-01

In this paper, the acoustic-phonetic characteristics of steady apical trills--trill sounds produced by the periodic vibration of the apex of the tongue--are studied. Signal processing methods, namely, zero-frequency filtering and zero-time liftering of speech signals, are used to analyze the excitation source and the resonance characteristics of the vocal tract system, respectively. Although it is natural to expect the effect of trilling on the resonances of the vocal tract system, it is interesting to note that trilling influences the glottal source of excitation as well. The excitation characteristics derived using zero-frequency filtering of speech signals are glottal epochs, strength of impulses at the glottal epochs, and instantaneous fundamental frequency of the glottal vibration. Analysis based on zero-time liftering of speech signals is used to study the dynamic resonance characteristics of vocal tract system during the production of trill sounds. Qualitative analysis of trill sounds in different vowel contexts, and the acoustic cues that may help spotting trills in continuous speech are discussed.

An experiment towards characterizing seahorse sound in a laboratory controlled environment

Digital Repository Service at National Institute of Oceanography (India)

Saran, A.K.; Sreepada, R.A.; Chakraborty, B.; Fernandes, W.A.; Srivastava, R.; Kuncolienker, D.S.; Gawde, G.

There are many reports of sounds produced by Seahorse (Hippocampus), however, little is known about the mechanism of sound production. Here, we investigate sound produced by the seahorse during feeding. We attempt to try to understand and analyze...

Audio-Visual Fusion for Sound Source Localization and Improved Attention

Energy Technology Data Exchange (ETDEWEB)

Lee, Byoung Gi; Choi, Jong Suk; Yoon, Sang Suk; Choi, Mun Taek; Kim, Mun Sang [Korea Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Dai Jin [Pohang University of Science and Technology, Pohang (Korea, Republic of)

2011-07-15

Service robots are equipped with various sensors such as vision camera, sonar sensor, laser scanner, and microphones. Although these sensors have their own functions, some of them can be made to work together and perform more complicated functions. AudioFvisual fusion is a typical and powerful combination of audio and video sensors, because audio information is complementary to visual information and vice versa. Human beings also mainly depend on visual and auditory information in their daily life. In this paper, we conduct two studies using audioFvision fusion: one is on enhancing the performance of sound localization, and the other is on improving robot attention through sound localization and face detection.

Audio-Visual Fusion for Sound Source Localization and Improved Attention

International Nuclear Information System (INIS)

Lee, Byoung Gi; Choi, Jong Suk; Yoon, Sang Suk; Choi, Mun Taek; Kim, Mun Sang; Kim, Dai Jin

2011-01-01

Service robots are equipped with various sensors such as vision camera, sonar sensor, laser scanner, and microphones. Although these sensors have their own functions, some of them can be made to work together and perform more complicated functions. AudioFvisual fusion is a typical and powerful combination of audio and video sensors, because audio information is complementary to visual information and vice versa. Human beings also mainly depend on visual and auditory information in their daily life. In this paper, we conduct two studies using audioFvision fusion: one is on enhancing the performance of sound localization, and the other is on improving robot attention through sound localization and face detection

Radio thermal sounding of natural environments

Science.gov (United States)

Gauss, Martin; Lomukhin, Yuriy

2017-11-01

At the moment, methods of sounding a status of soil, plant, forest and aquatic environments using radiometry and radar methods are intensively used. The main source of information using radar sounding is the back reflection ratio. The radiometric method is used for detection of the brightness temperature. In this paper, a communication between the back reflection ratio and the brightness temperature is described. This communication is proportional.

Syringeal specialization of frequency control during song production in the Bengalese finch (Lonchura striata domestica.

Directory of Open Access Journals (Sweden)

Kristen R Secora

Full Text Available Singing in songbirds is a complex, learned behavior which shares many parallels with human speech. The avian vocal organ (syrinx has two potential sound sources, and each sound generator is under unilateral, ipsilateral neural control. Different songbird species vary in their use of bilateral or unilateral phonation (lateralized sound production and rapid switching between left and right sound generation (interhemispheric switching of motor control. Bengalese finches (Lonchura striata domestica have received considerable attention, because they rapidly modify their song in response to manipulations of auditory feedback. However, how the left and right sides of the syrinx contribute to acoustic control of song has not been studied.Three manipulations of lateralized syringeal control of sound production were conducted. First, unilateral syringeal muscular control was eliminated by resection of the left or right tracheosyringeal portion of the hypoglossal nerve, which provides neuromuscular innervation of the syrinx. Spectral and temporal features of song were compared before and after lateralized nerve injury. In a second experiment, either the left or right sound source was devoiced to confirm the role of each sound generator in the control of acoustic phonology. Third, air pressure was recorded before and after unilateral denervation to enable quantification of acoustic change within individual syllables following lateralized nerve resection.These experiments demonstrate that the left sound source produces louder, higher frequency, lower entropy sounds, and the right sound generator produces lower amplitude, lower frequency, higher entropy sounds. The bilateral division of labor is complex and the frequency specialization is the opposite pattern observed in most songbirds. Further, there is evidence for rapid interhemispheric switching during song production. Lateralized control of song production in Bengalese finches may enhance acoustic

Efficient Geometric Sound Propagation Using Visibility Culling

Science.gov (United States)

Chandak, Anish

2011-07-01

Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering applications such as architectural acoustics. In this thesis, we present geometric sound propagation techniques which are faster than prior methods and map well to upcoming parallel multi-core CPUs. We model specular reflections by using the image-source method and model finite-edge diffraction by using the well-known Biot-Tolstoy-Medwin (BTM) model. We accelerate the computation of specular reflections by applying novel visibility algorithms, FastV and AD-Frustum, which compute visibility from a point. We accelerate finite-edge diffraction modeling by applying a novel visibility algorithm which computes visibility from a region. Our visibility algorithms are based on frustum tracing and exploit recent advances in fast ray-hierarchy intersections, data-parallel computations, and scalable, multi-core algorithms. The AD-Frustum algorithm adapts its computation to the scene complexity and allows small errors in computing specular reflection paths for higher computational efficiency. FastV and our visibility algorithm from a region are general, object-space, conservative visibility algorithms that together significantly reduce the number of image sources compared to other techniques while preserving the same accuracy. Our geometric propagation algorithms are an order of magnitude faster than prior approaches for modeling specular reflections and two to ten times faster for modeling finite-edge diffraction. Our algorithms are interactive, scale almost linearly on multi-core CPUs, and can handle large, complex, and dynamic scenes. We also compare the accuracy of our sound propagation algorithms with other methods. Once sound propagation is performed, it is desirable to listen to the propagated sound in interactive and engineering applications. We can generate smooth, artifact-free output audio signals by applying

The Opponent Channel Population Code of Sound Location Is an Efficient Representation of Natural Binaural Sounds

Science.gov (United States)

Młynarski, Wiktor

2015-01-01

In mammalian auditory cortex, sound source position is represented by a population of broadly tuned neurons whose firing is modulated by sounds located at all positions surrounding the animal. Peaks of their tuning curves are concentrated at lateral position, while their slopes are steepest at the interaural midline, allowing for the maximum localization accuracy in that area. These experimental observations contradict initial assumptions that the auditory space is represented as a topographic cortical map. It has been suggested that a “panoramic” code has evolved to match specific demands of the sound localization task. This work provides evidence suggesting that properties of spatial auditory neurons identified experimentally follow from a general design principle- learning a sparse, efficient representation of natural stimuli. Natural binaural sounds were recorded and served as input to a hierarchical sparse-coding model. In the first layer, left and right ear sounds were separately encoded by a population of complex-valued basis functions which separated phase and amplitude. Both parameters are known to carry information relevant for spatial hearing. Monaural input converged in the second layer, which learned a joint representation of amplitude and interaural phase difference. Spatial selectivity of each second-layer unit was measured by exposing the model to natural sound sources recorded at different positions. Obtained tuning curves match well tuning characteristics of neurons in the mammalian auditory cortex. This study connects neuronal coding of the auditory space with natural stimulus statistics and generates new experimental predictions. Moreover, results presented here suggest that cortical regions with seemingly different functions may implement the same computational strategy-efficient coding. PMID:25996373

Low frequency sounds in dwellings : A case control study

NARCIS (Netherlands)

van den Berg, Frits (G P)

2000-01-01

The purpose of this study is to systematically assess the level and spectral distribution of low frequency (LF) sounds in dwellings. Measurements of broad and narrow hand sound levels have been made in 36 Dutch dwellings in 1998. In 19 dwellings there were complaints about LF noise, in 17 others no

Control source development for reduction of noise transmitted through a double panel structure

OpenAIRE

Ho, J.

2014-01-01

A double panel structure, which consists of two panels with air in between, is widely adopted in many applications such as aerospace, automotive industries, and buildings due to its low sound transmission at high frequencies, low heat transmission, and low weight. Nevertheless, the resonance of the cavity and the poor sound transmission loss at low frequencies limit the double panel’s noise control performance. Applying active structural acoustic control to the panels or active noise control ...

Use of Quality Controlled AIRS Temperature Soundings to Improve Forecast Skill

Science.gov (United States)

Susskind, Joel; Reale, Oreste; Iredell, Lena

2010-01-01

AIRS was launched on EOS Aqua on May 4, 2002, together with AMSU-A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU-A are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. Also included are the clear column radiances used to derive these products which are representative of the radiances AIRS would have seen if there were no clouds in the field of view. All products also have error estimates. The sounding goals of AIRS are to produce 1 km tropospheric layer mean temperatures with an rms error of 1K, and layer precipitable water with an rms error of 20 percent, in cases with up to 90 percent effective cloud cover. The products are designed for data assimilation purposes for the improvement of numerical weather prediction, as well as for the study of climate and meteorological processes. With regard to data assimilation, one can use either the products themselves or the clear column radiances from which the products were derived. The AIRS Version 5 retrieval algorithm is now being used operationally at the Goddard DISC in the routine generation of geophysical parameters derived from AIRS/AMSU data. A major innovation in Version 5 is the ability to generate case-by-case level-by-level error estimates for retrieved quantities and clear column radiances, and the use of these error estimates for Quality Control. The temperature profile error estimates are used to determine a case-by-case characteristic pressure pbest, down to which the profile is considered acceptable for data assimilation purposes. The characteristic pressure p(sub best) is determined by comparing the case dependent error estimate (delta)T(p) to the threshold values (Delta)T(p). The AIRS Version 5 data set provides error estimates of T(p) at all levels, and also profile dependent values of pbest based

Foley Sounds vs Real Sounds

DEFF Research Database (Denmark)

Trento, Stefano; Götzen, Amalia De

2011-01-01

This paper is an initial attempt to study the world of sound effects for motion pictures, also known as Foley sounds. Throughout several audio and audio-video tests we have compared both Foley and real sounds originated by an identical action. The main purpose was to evaluate if sound effects...

Good vibrations: Controlling light with sound (Conference Presentation)

Science.gov (United States)

Eggleton, Benjamin J.; Choudhary, Amol

2016-10-01

One of the surprises of nonlinear optics, is that light may interact strongly with sound. Intense laser light literally "shakes" the glass in optical fibres, exciting acoustic waves (sound) in the fibre. Under the right conditions, it leads to a positive feedback loop between light and sound termed "Stimulated Brillouin Scattering," or simply SBS. This nonlinear interaction can amplify or filter light waves with extreme precision in frequency which makes it uniquely suited to solve key problems in the fields of defence, biomedicine, wireless communications, spectroscopy and imaging. We have achieved the first demonstration of SBS in compact chip-scale structures, carefully designed so that the optical fields and the acoustic fields are simultaneously confined and guided. This new platform has opened a range of new functionalities that are being applied in communications and defence with breathtaking performance and compactness. My talk will introduce this new field and review our progress and achievements, including silicon based optical phononic processor.

Sound quality indicators for urban places in Paris cross-validated by Milan data.

Science.gov (United States)

Ricciardi, Paola; Delaitre, Pauline; Lavandier, Catherine; Torchia, Francesca; Aumond, Pierre

2015-10-01

A specific smartphone application was developed to collect perceptive and acoustic data in Paris. About 3400 questionnaires were analyzed, regarding the global sound environment characterization, the perceived loudness of some emergent sources and the presence time ratio of sources that do not emerge from the background. Sound pressure level was recorded each second from the mobile phone's microphone during a 10-min period. The aim of this study is to propose indicators of urban sound quality based on linear regressions with perceptive variables. A cross validation of the quality models extracted from Paris data was carried out by conducting the same survey in Milan. The proposed sound quality general model is correlated with the real perceived sound quality (72%). Another model without visual amenity and familiarity is 58% correlated with perceived sound quality. In order to improve the sound quality indicator, a site classification was performed by Kohonen's Artificial Neural Network algorithm, and seven specific class models were developed. These specific models attribute more importance on source events and are slightly closer to the individual data than the global model. In general, the Parisian models underestimate the sound quality of Milan environments assessed by Italian people.

Long-term exposure to noise impairs cortical sound processing and attention control.

Science.gov (United States)

Kujala, Teija; Shtyrov, Yury; Winkler, Istvan; Saher, Marieke; Tervaniemi, Mari; Sallinen, Mikael; Teder-Sälejärvi, Wolfgang; Alho, Kimmo; Reinikainen, Kalevi; Näätänen, Risto

2004-11-01

Long-term exposure to noise impairs human health, causing pathological changes in the inner ear as well as other anatomical and physiological deficits. Numerous individuals are daily exposed to excessive noise. However, there is a lack of systematic research on the effects of noise on cortical function. Here we report data showing that long-term exposure to noise has a persistent effect on central auditory processing and leads to concurrent behavioral deficits. We found that speech-sound discrimination was impaired in noise-exposed individuals, as indicated by behavioral responses and the mismatch negativity brain response. Furthermore, irrelevant sounds increased the distractibility of the noise-exposed subjects, which was shown by increased interference in task performance and aberrant brain responses. These results demonstrate that long-term exposure to noise has long-lasting detrimental effects on central auditory processing and attention control.

78 FR 13869 - Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy...

Science.gov (United States)

2013-03-01

...-123-LNG; 12-128-NG; 12-148-NG; 12- 158-NG] Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; Puget Sound Energy, Inc.; CE FLNG, LLC; Consolidated...-NG Puget Sound Energy, Inc Order granting long- term authority to import/export natural gas from/to...

Acoustics in Research Facilities--Control of Wanted and Unwanted Sound. Laboratory Design Notes.

Science.gov (United States)

Newman, Robert B.

Common and special acoustics problems are discussed in relation to the design and construction of research facilities. Following a brief examination of design criteria for the control of wanted and unwanted sound, the technology for achieving desired results is discussed. Emphasis is given to various design procedures and materials for the control…

What the Toadfish Ear Tells the Toadfish Brain About Sound.

Science.gov (United States)

Edds-Walton, Peggy L

2016-01-01

Of the three, paired otolithic endorgans in the ear of teleost fishes, the saccule is the one most often demonstrated to have a major role in encoding frequencies of biologically relevant sounds. The toadfish saccule also encodes sound level and sound source direction in the phase-locked activity conveyed via auditory afferents to nuclei of the ipsilateral octaval column in the medulla. Although paired auditory receptors are present in teleost fishes, binaural processes were believed to be unimportant due to the speed of sound in water and the acoustic transparency of the tissues in water. In contrast, there are behavioral and anatomical data that support binaural processing in fishes. Studies in the toadfish combined anatomical tract-tracing and physiological recordings from identified sites along the ascending auditory pathway to document response characteristics at each level. Binaural computations in the medulla and midbrain sharpen the directional information provided by the saccule. Furthermore, physiological studies in the central nervous system indicated that encoding frequency, sound level, temporal pattern, and sound source direction are important components of what the toadfish ear tells the toadfish brain about sound.

Evaluating Environmental Sounds from a Presence Perspective for Virtual Reality Applications

DEFF Research Database (Denmark)

Nordahl, Rolf

2010-01-01

We propose a methodology to design and evaluate environmental sounds for virtual environments. We propose to combine physically modeled sound events with recorded soundscapes. Physical models are used to provide feedback to users’ actions, while soundscapes reproduce the characteristic soundmarks...... as well as self-induced interactive sounds simulated using physical models. Results show that subjects’ motion in the environment is significantly enhanced when dynamic sound sources and sound of egomotion are rendered in the environment....

New perspectives on mechanisms of sound generation in songbirds

DEFF Research Database (Denmark)

Goller, Franz; Larsen, Ole Næsbye

2002-01-01

-tone mechanism similar to human phonation with the labia forming a pneumatic valve. The classical avian model proposed that vibrations of the thin medial tympaniform membranes are the primary sound generating mechanism. As a direct test of these two hypotheses we ablated the medial tympaniform membranes in two......The physical mechanisms of sound generation in the vocal organ, the syrinx, of songbirds have been investigated mostly with indirect methods. Recent direct endoscopic observation identified vibrations of the labia as the principal sound source. This model suggests sound generation in a pulse...... atmosphere) as well as direct (labial vibration during tonal sound) measurements of syringeal vibrations support a vibration-based soundgenerating mechanism even for tonal sounds....

Effects of task-switching on neural representations of ambiguous sound input.

Science.gov (United States)

Sussman, Elyse S; Bregman, Albert S; Lee, Wei-Wei

2014-11-01

The ability to perceive discrete sound streams in the presence of competing sound sources relies on multiple mechanisms that organize the mixture of the auditory input entering the ears. Many studies have focused on mechanisms that contribute to integrating sounds that belong together into one perceptual stream (integration) and segregating those that come from different sound sources (segregation). However, little is known about mechanisms that allow us to perceive individual sound sources within a dynamically changing auditory scene, when the input may be ambiguous, and heard as either integrated or segregated. This study tested the question of whether focusing on one of two possible sound organizations suppressed representation of the alternative organization. We presented listeners with ambiguous input and cued them to switch between tasks that used either the integrated or the segregated percept. Electrophysiological measures indicated which organization was currently maintained in memory. If mutual exclusivity at the neural level was the rule, attention to one of two possible organizations would preclude neural representation of the other. However, significant MMNs were elicited to both the target organization and the unattended, alternative organization, along with the target-related P3b component elicited only to the designated target organization. Results thus indicate that both organizations (integrated and segregated) were simultaneously maintained in memory regardless of which task was performed. Focusing attention to one aspect of the sounds did not abolish the alternative, unattended organization when the stimulus input was ambiguous. In noisy environments, such as walking on a city street, rapid and flexible adaptive processes are needed to help facilitate rapid switching to different sound sources in the environment. Having multiple representations available to the attentive system would allow for such flexibility, needed in everyday situations to

Evaluating Environmental Sounds from a Presence Perspective for Virtual Reality Applications

Directory of Open Access Journals (Sweden)

Nordahl Rolf

2010-01-01

Full Text Available We propose a methodology to design and evaluate environmental sounds for virtual environments. We propose to combine physically modeled sound events with recorded soundscapes. Physical models are used to provide feedback to users' actions, while soundscapes reproduce the characteristic soundmarks of an environment. In this particular case, physical models are used to simulate the act of walking in the botanical garden of the city of Prague, while soundscapes are used to reproduce the particular sound of the garden. The auditory feedback designed was combined with a photorealistic reproduction of the same garden. A between-subject experiment was conducted, where 126 subjects participated, involving six different experimental conditions, including both uni- and bimodal stimuli (auditory and visual. The auditory stimuli consisted of several combinations of auditory feedback, including static sound sources as well as self-induced interactive sounds simulated using physical models. Results show that subjects' motion in the environment is significantly enhanced when dynamic sound sources and sound of egomotion are rendered in the environment.

Sound localization with head movement: implications for 3-d audio displays.

Directory of Open Access Journals (Sweden)

Ken Ian McAnally

2014-08-01

Full Text Available Previous studies have shown that the accuracy of sound localization is improved if listeners are allowed to move their heads during signal presentation. This study describes the function relating localization accuracy to the extent of head movement in azimuth. Sounds that are difficult to localize were presented in the free field from sources at a wide range of azimuths and elevations. Sounds remained active until the participants’ heads had rotated through windows ranging in width of 2°, 4°, 8°, 16°, 32°, or 64° of azimuth. Error in determining sound-source elevation and the rate of front/back confusion were found to decrease with increases in azimuth window width. Error in determining sound-source lateral angle was not found to vary with azimuth window width. Implications for 3-d audio displays: The utility of a 3-d audio display for imparting spatial information is likely to be improved if operators are able to move their heads during signal presentation. Head movement may compensate in part for a paucity of spectral cues to sound-source location resulting from limitations in either the audio signals presented or the directional filters (i.e., head-related transfer functions used to generate a display. However, head movements of a moderate size (i.e., through around 32° of azimuth may be required to ensure that spatial information is conveyed with high accuracy.

Shape analysis of pulsed second sound in He II

International Nuclear Information System (INIS)

Worthington, T.; Yan, J.; Trefny, J.U.

1976-01-01

Second sound in He II has been observed using a heat pulse method. At temperatures where well-developed second sound is observed, the entire pulse shape can be understood if heat sources and geometrical effects are properly taken into account. 4 figures

Microsoft C#.NET program and electromagnetic depth sounding for large loop source

Science.gov (United States)

Prabhakar Rao, K.; Ashok Babu, G.

2009-07-01

A program, in the C# (C Sharp) language with Microsoft.NET Framework, is developed to compute the normalized vertical magnetic field of a horizontal rectangular loop source placed on the surface of an n-layered earth. The field can be calculated either inside or outside the loop. Five C# classes with member functions in each class are, designed to compute the kernel, Hankel transform integral, coefficients for cubic spline interpolation between computed values and the normalized vertical magnetic field. The program computes the vertical magnetic field in the frequency domain using the integral expressions evaluated by a combination of straightforward numerical integration and the digital filter technique. The code utilizes different object-oriented programming (OOP) features. It finally computes the amplitude and phase of the normalized vertical magnetic field. The computed results are presented for geometric and parametric soundings. The code is developed in Microsoft.NET visual studio 2003 and uses various system class libraries.

An open access database for the evaluation of heart sound algorithms.

Science.gov (United States)

Liu, Chengyu; Springer, David; Li, Qiao; Moody, Benjamin; Juan, Ricardo Abad; Chorro, Francisco J; Castells, Francisco; Roig, José Millet; Silva, Ikaro; Johnson, Alistair E W; Syed, Zeeshan; Schmidt, Samuel E; Papadaniil, Chrysa D; Hadjileontiadis, Leontios; Naseri, Hosein; Moukadem, Ali; Dieterlen, Alain; Brandt, Christian; Tang, Hong; Samieinasab, Maryam; Samieinasab, Mohammad Reza; Sameni, Reza; Mark, Roger G; Clifford, Gari D

2016-12-01

In the past few decades, analysis of heart sound signals (i.e. the phonocardiogram or PCG), especially for automated heart sound segmentation and classification, has been widely studied and has been reported to have the potential value to detect pathology accurately in clinical applications. However, comparative analyses of algorithms in the literature have been hindered by the lack of high-quality, rigorously validated, and standardized open databases of heart sound recordings. This paper describes a public heart sound database, assembled for an international competition, the PhysioNet/Computing in Cardiology (CinC) Challenge 2016. The archive comprises nine different heart sound databases sourced from multiple research groups around the world. It includes 2435 heart sound recordings in total collected from 1297 healthy subjects and patients with a variety of conditions, including heart valve disease and coronary artery disease. The recordings were collected from a variety of clinical or nonclinical (such as in-home visits) environments and equipment. The length of recording varied from several seconds to several minutes. This article reports detailed information about the subjects/patients including demographics (number, age, gender), recordings (number, location, state and time length), associated synchronously recorded signals, sampling frequency and sensor type used. We also provide a brief summary of the commonly used heart sound segmentation and classification methods, including open source code provided concurrently for the Challenge. A description of the PhysioNet/CinC Challenge 2016, including the main aims, the training and test sets, the hand corrected annotations for different heart sound states, the scoring mechanism, and associated open source code are provided. In addition, several potential benefits from the public heart sound database are discussed.

Sound engineering for diesel engines; Sound Engineering an Dieselmotoren

Energy Technology Data Exchange (ETDEWEB)

Enderich, A.; Fischer, R. [MAHLE Filtersysteme GmbH, Stuttgart (Germany)

2006-07-01

The strong acceptance for vehicles powered by turbo-charged diesel engines encourages several manufacturers to think about sportive diesel concepts. The approach of suppressing unpleasant noise by the application of distinctive insulation steps is not adequate to satisfy sportive needs. The acoustics cannot follow the engine's performance. This report documents, that it is possible to give diesel-powered vehicles a sportive sound characteristic by using an advanced MAHLE motor-sound-system with a pressure-resistant membrane and an integrated load controlled flap. With this the specific acoustic disadvantages of the diesel engine, like the ''diesel knock'' or a rough engine running can be masked. However, by the application of a motor-sound-system you must not negate the original character of the diesel engine concept, but accentuate its strong torque characteristic in the middle engine speed range. (orig.)

Generation and control of sound bullets with a nonlinear acoustic lens.

Science.gov (United States)

Spadoni, Alessandro; Daraio, Chiara

2010-04-20

Acoustic lenses are employed in a variety of applications, from biomedical imaging and surgery to defense systems and damage detection in materials. Focused acoustic signals, for example, enable ultrasonic transducers to image the interior of the human body. Currently however the performance of acoustic devices is limited by their linear operational envelope, which implies relatively inaccurate focusing and low focal power. Here we show a dramatic focusing effect and the generation of compact acoustic pulses (sound bullets) in solid and fluid media, with energies orders of magnitude greater than previously achievable. This focusing is made possible by a tunable, nonlinear acoustic lens, which consists of ordered arrays of granular chains. The amplitude, size, and location of the sound bullets can be controlled by varying the static precompression of the chains. Theory and numerical simulations demonstrate the focusing effect, and photoelasticity experiments corroborate it. Our nonlinear lens permits a qualitatively new way of generating high-energy acoustic pulses, which may improve imaging capabilities through increased accuracy and signal-to-noise ratios and may lead to more effective nonintrusive scalpels, for example, for cancer treatment.

Synthesis of Directional Sources Using Wave Field Synthesis, Possibilities, and Limitations

Directory of Open Access Journals (Sweden)

Corteel E

2007-01-01

Full Text Available The synthesis of directional sources using wave field synthesis is described. The proposed formulation relies on an ensemble of elementary directivity functions based on a subset of spherical harmonics. These can be combined to create and manipulate directivity characteristics of the synthesized virtual sources. The WFS formulation introduces artifacts in the synthesized sound field for both ideal and real loudspeakers. These artifacts can be partly compensated for using dedicated equalization techniques. A multichannel equalization technique is shown to provide accurate results thus enabling for the manipulation of directional sources with limited reconstruction artifacts. Applications of directional sources to the control of the direct sound field and the interaction with the listening room are discussed.

Experimental validation of sound field control with a circular double-layer array of loudspeakers

DEFF Research Database (Denmark)

Chang, Jiho; Jacobsen, Finn

2013-01-01

This paper is concerned with experimental validation of a recently proposed method of controlling sound fields with a circular double-layer array of loudspeakers [Chang and Jacobsen, J. Acoust. Soc. Am. 131(6), 4518-4525 (2012)]. The double-layer of loudspeakers is realized with 20 pairs of closed...

3rd Symposium on Fluid-Structure-Sound Interactions and Control

CERN Document Server

Lucey, AD; Liu, Yang; Huang, Lixi

2016-01-01

These proceedings primarily focus on advances in the theory, experiments, and numerical simulations of turbulence in the contexts of flow-induced vibration and noise, as well as their control. Fluid-related structural vibration and noise problems are often encountered in many engineering fields, increasingly making them a cause for concern. The FSSIC conference, held on 5-9 July 2015 in Perth, featured prominent keynote speakers such as John Kim, Nigel Peake, Song Fu and Colin Hansen, as well as talks on a broad range of topics: turbulence, fluid-structure interaction, fluid-related noise and the control/management aspects of these research areas, many of which are clearly interdisciplinary in nature. It provided a forum for academics, scientists and engineers working in all branches of Fluid-Structure-Sound Interactions and Control (FSSIC) to exchange and share the latest developments, ideas and advances, bringing them together researchers from East and West to push forward the frontiers of FSSIC, ensuring t...

Psychological restoration can depend on stimulus-source attribution: A challenge for the evolutionary account?

Directory of Open Access Journals (Sweden)

Andreas Haga

2016-11-01

Full Text Available Visiting or viewing nature environments can have restorative psychological effects, while exposure to the built environment typically has less positive effects. A classic view is that this difference in restorative potential of nature and built environments depends on differences in the intrinsic characteristics of the stimuli. In addition, an evolutionary account is often assumed whereby restoration is believed to be a hardwired response to nature’s stimulus-features. Here, we propose the novel hypothesis that the restorative effects of a stimulus do not entirely depend on the stimulus-features per se, but also on the meaning that people assign to the stimulus. Participants conducted cognitively demanding tests prior to and after a brief pause. During the pause, the participants were exposed to an ambiguous sound consisting of pink noise with white noise interspersed. Participants in the nature sound-source condition were told that the sound originated from a nature scene with a waterfall; participants in the industrial sound-source condition were told that the sound originated from an industrial environment with machinery; and participants in the control condition were told nothing about the sound origin. Self-reported mental exhaustion showed that participants in the nature sound-source condition were more psychologically restored after the pause than participants in the industrial sound-source condition. One potential interpretation of the results is that restoration from nature experiences depends on learned, positive associations with nature; not only on hardwired responses shaped by evolution.

Second Sound for Heat Source Localization

CERN Document Server

Vennekate, Hannes; Uhrmacher, Michael; Quadt, Arnulf; Grosse-Knetter, Joern

2011-01-01

Defects on the surface of superconducting cavities can limit their accelerating gradient by localized heating. This results in a phase transition to the normal conduction state | a quench. A new application, involving Oscillating Superleak Transducers (OST) to locate such quench inducing heat spots on the surface of the cavities, has been developed by D. Hartill et al. at Cornell University in 2008. The OSTs enable the detection of heat transfer via second sound in super uid helium. This thesis presents new results on the analysis of their signal. Its behavior has been studied for dierent circumstances at setups at the University of Gottingen and at CERN. New approaches for an automated signal processing have been developed. Furthermore, a rst test setup for a single-cell Superconducting Proton Linac (SPL) cavity has been prepared. Recommendations of a better signal retrieving for its operation are presented.

Characterization of sound emitted by wind machines used for frost control

Energy Technology Data Exchange (ETDEWEB)

Gambino, V.; Gambino, T. [Aercoustics Engineering Ltd., Toronto, ON (Canada); Fraser, H.W. [Ontario Ministry of Agriculture, Food and Rural Affairs, Vineland, ON (Canada)

2007-07-01

Wind machines are used in Niagara-on-the-Lake to protect cold-sensitive crops against cold injury during winter's extreme cold temperatures,spring's late frosts and autumn's early frosts. The number of wind machines in Ontario has about doubled annually from only a few in the late 1990's, to more than 425 in 2006. They are not used for generating power. Noise complaints have multiplied as the number of wind machines has increased. The objective of this study was to characterize the sound produced by wind machines; learn why residents are annoyed by wind machine noise; and suggest ways to possibly reduce sound emissions. One part of the study explored acoustic emission characteristics, the sonic differences of units made by different manufacturers, sound propagation properties under typical use atmospheric conditions and low frequency noise impact potential. Tests were conducted with a calibrated Larson Davis 2900B portable spectrum analyzer. Sound was measured with a microphone whose frequency response covered the range 4 Hz to 20 kHz. The study examined and found several unique acoustic properties that are characteristic of wind machines. It was determined that noise from wind machines is due to both aerodynamic and mechanical effects, but aerodynamic sounds were found to be the most significant. It was concluded that full range or broadband sounds manifest themselves as noise components that extend throughout the audible frequency range from the bladepass frequency to upwards of 1000 Hz. The sound spectrum of a wind machine is full natural tones and impulses that give it a readily identifiable acoustic character. Atmospheric conditions including temperature, lapse rate, relative humidity, mild winds, gradients and atmospheric turbulence all play a significant role in the long range outdoor propagation of sound from wind machines. 6 refs., 6 figs.

Spider web-structured labyrinthine acoustic metamaterials for low-frequency sound control

Science.gov (United States)

Krushynska, A. O.; Bosia, F.; Miniaci, M.; Pugno, N. M.

2017-10-01

Attenuating low-frequency sound remains a challenge, despite many advances in this field. Recently-developed acoustic metamaterials are characterized by unusual wave manipulation abilities that make them ideal candidates for efficient subwavelength sound control. In particular, labyrinthine acoustic metamaterials exhibit extremely high wave reflectivity, conical dispersion, and multiple artificial resonant modes originating from the specifically-designed topological architectures. These features enable broadband sound attenuation, negative refraction, acoustic cloaking and other peculiar effects. However, hybrid and/or tunable metamaterial performance implying enhanced wave reflection and simultaneous presence of conical dispersion at desired frequencies has not been reported so far. In this paper, we propose a new type of labyrinthine acoustic metamaterials (LAMMs) with hybrid dispersion characteristics by exploiting spider web-structured configurations. The developed design approach consists in adding a square surrounding frame to sectorial circular-shaped labyrinthine channels described in previous publications (e.g. (11)). Despite its simplicity, this approach provides tunability in the metamaterial functionality, such as the activation/elimination of subwavelength band gaps and negative group-velocity modes by increasing/decreasing the edge cavity dimensions. Since these cavities can be treated as extensions of variable-width internal channels, it becomes possible to exploit geometrical features, such as channel width, to shift the band gap position and size to desired frequencies. Time transient simulations demonstrate the effectiveness of the proposed metastructures for wave manipulation in terms of transmission or reflection coefficients, amplitude attenuation and time delay at subwavelength frequencies. The obtained results can be important for practical applications of LAMMs such as lightweight acoustic barriers with enhanced broadband wave

Spider web-structured labyrinthine acoustic metamaterials for low-frequency sound control

International Nuclear Information System (INIS)

Krushynska, A O; Bosia, F; Miniaci, M; Pugno, N M

2017-01-01

Attenuating low-frequency sound remains a challenge, despite many advances in this field. Recently-developed acoustic metamaterials are characterized by unusual wave manipulation abilities that make them ideal candidates for efficient subwavelength sound control. In particular, labyrinthine acoustic metamaterials exhibit extremely high wave reflectivity, conical dispersion, and multiple artificial resonant modes originating from the specifically-designed topological architectures. These features enable broadband sound attenuation, negative refraction, acoustic cloaking and other peculiar effects. However, hybrid and/or tunable metamaterial performance implying enhanced wave reflection and simultaneous presence of conical dispersion at desired frequencies has not been reported so far. In this paper, we propose a new type of labyrinthine acoustic metamaterials (LAMMs) with hybrid dispersion characteristics by exploiting spider web-structured configurations. The developed design approach consists in adding a square surrounding frame to sectorial circular-shaped labyrinthine channels described in previous publications (e.g. (11)). Despite its simplicity, this approach provides tunability in the metamaterial functionality, such as the activation/elimination of subwavelength band gaps and negative group-velocity modes by increasing/decreasing the edge cavity dimensions. Since these cavities can be treated as extensions of variable-width internal channels, it becomes possible to exploit geometrical features, such as channel width, to shift the band gap position and size to desired frequencies. Time transient simulations demonstrate the effectiveness of the proposed metastructures for wave manipulation in terms of transmission or reflection coefficients, amplitude attenuation and time delay at subwavelength frequencies. The obtained results can be important for practical applications of LAMMs such as lightweight acoustic barriers with enhanced broadband wave

Problems in nonlinear acoustics: Pulsed finite amplitude sound beams, nonlinear acoustic wave propagation in a liquid layer, nonlinear effects in asymmetric cylindrical sound beams, effects of absorption on the interaction of sound beams, and parametric receiving arrays

Science.gov (United States)

Hamilton, Mark F.

1990-12-01

This report discusses five projects all of which involve basic theoretical research in nonlinear acoustics: (1) pulsed finite amplitude sound beams are studied with a recently developed time domain computer algorithm that solves the KZK nonlinear parabolic wave equation; (2) nonlinear acoustic wave propagation in a liquid layer is a study of harmonic generation and acoustic soliton information in a liquid between a rigid and a free surface; (3) nonlinear effects in asymmetric cylindrical sound beams is a study of source asymmetries and scattering of sound by sound at high intensity; (4) effects of absorption on the interaction of sound beams is a completed study of the role of absorption in second harmonic generation and scattering of sound by sound; and (5) parametric receiving arrays is a completed study of parametric reception in a reverberant environment.

Active control of sound transmission through a rectangular panel using point-force actuators and piezoelectric film sensors.

Science.gov (United States)

Sanada, Akira; Higashiyama, Kouji; Tanaka, Nobuo

2015-01-01

This study deals with the active control of sound transmission through a rectangular panel, based on single input, single output feedforward vibration control using point-force actuators and piezoelectric film sensors. It focuses on the phenomenon in which the sound power transmitted through a finite-sized panel drops significantly at some frequencies just below the resonance frequencies of the panel in the low-frequency range as a result of modal coupling cancellation. In a previous study, it was shown that when point-force actuators are located on nodal lines for the frequency at which this phenomenon occurs, a force equivalent to the incident sound wave can act on the panel. In this study, a practical method for sensing volume velocity using a small number of piezoelectric film strips is investigated. It is found that two quadratically shaped piezoelectric film strips, attached at the same nodal lines as those where the actuators were placed, can sense the volume velocity approximately in the low-frequency range. Results of simulations show that combining the proposed actuation method and the sensing method can achieve a practical control effect at low frequencies over a wide frequency range. Finally, experiments are carried out to demonstrate the validity and feasibility of the proposed method.

Human-assisted sound event recognition for home service robots.

Science.gov (United States)

Do, Ha Manh; Sheng, Weihua; Liu, Meiqin

This paper proposes and implements an open framework of active auditory learning for a home service robot to serve the elderly living alone at home. The framework was developed to realize the various auditory perception capabilities while enabling a remote human operator to involve in the sound event recognition process for elderly care. The home service robot is able to estimate the sound source position and collaborate with the human operator in sound event recognition while protecting the privacy of the elderly. Our experimental results validated the proposed framework and evaluated auditory perception capabilities and human-robot collaboration in sound event recognition.

Replacing the Orchestra? - The Discernibility of Sample Library and Live Orchestra Sounds.

Directory of Open Access Journals (Sweden)

Reinhard Kopiez

Full Text Available Recently, musical sounds from pre-recorded orchestra sample libraries (OSL have become indispensable in music production for the stage or popular charts. Surprisingly, it is unknown whether human listeners can identify sounds as stemming from real orchestras or OSLs. Thus, an internet-based experiment was conducted to investigate whether a classic orchestral work, produced with sounds from a state-of-the-art OSL, could be reliably discerned from a live orchestra recording of the piece. It could be shown that the entire sample of listeners (N = 602 on average identified the correct sound source at 72.5%. This rate slightly exceeded Alan Turing's well-known upper threshold of 70% for a convincing, simulated performance. However, while sound experts tended to correctly identify the sound source, participants with lower listening expertise, who resembled the majority of music consumers, only achieved 68.6%. As non-expert listeners in the experiment were virtually unable to tell the real-life and OSL sounds apart, it is assumed that OSLs will become more common in music production for economic reasons.

Sound

CERN Document Server

Robertson, William C

2003-01-01

Muddled about what makes music? Stuck on the study of harmonics? Dumbfounded by how sound gets around? Now you no longer have to struggle to teach concepts you really don t grasp yourself. Sound takes an intentionally light touch to help out all those adults science teachers, parents wanting to help with homework, home-schoolers seeking necessary scientific background to teach middle school physics with confidence. The book introduces sound waves and uses that model to explain sound-related occurrences. Starting with the basics of what causes sound and how it travels, you'll learn how musical instruments work, how sound waves add and subtract, how the human ear works, and even why you can sound like a Munchkin when you inhale helium. Sound is the fourth book in the award-winning Stop Faking It! Series, published by NSTA Press. Like the other popular volumes, it is written by irreverent educator Bill Robertson, who offers this Sound recommendation: One of the coolest activities is whacking a spinning metal rod...

Effects of Interaural Level and Time Differences on the Externalization of Sound

DEFF Research Database (Denmark)

Dau, Torsten; Catic, Jasmina; Santurette, Sébastien

Distant sound sources in our environment are perceived as externalized and are thus properly localized in both direction and distance. This is due to the acoustic filtering by the head, torso, and external ears, which provides frequency dependent shaping of binaural cues, such as interaural level...... differences (ILDs) and interaural time differences (ITDs). Further, the binaural cues provided by reverberation in an enclosed space may also contribute to externalization. While these spatial cues are available in their natural form when listening to real-world sound sources, hearing-aid signal processing...... is consistent with the physical analysis that showed that a decreased distance to the sound source also reduced the fluctuations in ILDs....

Review of sound card photogates

International Nuclear Information System (INIS)

Gingl, Zoltan; Mingesz, Robert; Mellar, Janos; Makra, Peter

2011-01-01

Photogates are probably the most commonly used electronic instruments to aid experiments in the field of mechanics. Although they are offered by many manufacturers, they can be too expensive to be widely used in all classrooms, in multiple experiments or even at home experimentation. Today all computers have a sound card - an interface for analogue signals. It is possible to make very simple yet highly accurate photogates for cents, while much more sophisticated solutions are also available at a still very low cost. In our paper we show several experimentally tested ways of implementing sound card photogates in detail, and we also provide full-featured, free, open-source photogate software as a much more efficient experimentation tool than the usually used sound recording programs. Further information is provided on a dedicated web page, www.noise.physx.u-szeged.hu/edudev.

Cluster-Randomized Controlled Trial Evaluating the Effectiveness of Computer-Assisted Intervention Delivered by Educators for Children with Speech Sound Disorders

Science.gov (United States)

McLeod, Sharynne; Baker, Elise; McCormack, Jane; Wren, Yvonne; Roulstone, Sue; Crowe, Kathryn; Masso, Sarah; White, Paul; Howland, Charlotte

2017-01-01

Purpose: The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD). Method: The Sound Start Study was a cluster-randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 parents and educators of 4- and…

A model for calculating specular and diffuse reflections in outdoor sound propagation

NARCIS (Netherlands)

Salomons, E.M.

2006-01-01

In many practical outdoor situations, the direct sound path between a noise source and a receiver is screened by an obstacle. In these situations indirect sound paths become important, in particular reflections of sound waves. Reflections may occur at objects such as a vertical wall, but also at the

Control of sealed radioactive sources in Peru

International Nuclear Information System (INIS)

Ramirez Quijada, R.

2001-01-01

The paper describes the inventory of radioactive sources in Peru and assesses the control. Three groups of source conditions are established: controlled sources, known sources, and lost and orphan sources. The potential risk, described as not significant, for producing accidents is established and the needed measures are discussed. The paper concludes that, while the control on sealed sources is good, there is still room for improvement. (author)

Characterizing large river sounds: Providing context for understanding the environmental effects of noise produced by hydrokinetic turbines.

Science.gov (United States)

Bevelhimer, Mark S; Deng, Z Daniel; Scherelis, Constantin

2016-01-01

Underwater noise associated with the installation and operation of hydrokinetic turbines in rivers and tidal zones presents a potential environmental concern for fish and marine mammals. Comparing the spectral quality of sounds emitted by hydrokinetic turbines to natural and other anthropogenic sound sources is an initial step at understanding potential environmental impacts. Underwater recordings were obtained from passing vessels and natural underwater sound sources in static and flowing waters. Static water measurements were taken in a lake with minimal background noise. Flowing water measurements were taken at a previously proposed deployment site for hydrokinetic turbines on the Mississippi River, where sounds created by flowing water are part of all measurements, both natural ambient and anthropogenic sources. Vessel sizes ranged from a small fishing boat with 60 hp outboard motor to an 18-unit barge train being pushed upstream by tugboat. As expected, large vessels with large engines created the highest sound levels, which were, on average, 40 dB greater than the sound created by an operating hydrokinetic turbine. A comparison of sound levels from the same sources at different distances using both spherical and cylindrical sound attenuation functions suggests that spherical model results more closely approximate observed sound attenuation.

Spatial aspects of sound quality - and by multichannel systems subjective assessment of sound reproduced by stereo

DEFF Research Database (Denmark)

Choisel, Sylvain

the fidelity with which sound reproduction systems can re-create the desired stereo image, a laser pointing technique was developed to accurately collect subjects' responses in a localization task. This method is subsequently applied in an investigation of the effects of loudspeaker directivity...... on the perceived direction of panned sources. The second part of the thesis addresses the identification of auditory attributes which play a role in the perception of sound reproduced by multichannel systems. Short musical excerpts were presented in mono, stereo and several multichannel formats to evoke various...

EXTRACTION OF SPATIAL PARAMETERS FROM CLASSIFIED LIDAR DATA AND AERIAL PHOTOGRAPH FOR SOUND MODELING

Directory of Open Access Journals (Sweden)

S. Biswas

2012-07-01

Full Text Available Prediction of outdoor sound levels in 3D space is important for noise management, soundscaping etc. Sound levels at outdoor can be predicted using sound propagation models which need terrain parameters. The existing practices of incorporating terrain parameters into models are often limited due to inadequate data or inability to determine accurate sound transmission paths through a terrain. This leads to poor accuracy in modelling. LIDAR data and Aerial Photograph (or Satellite Images provide opportunity to incorporate high resolution data into sound models. To realize this, identification of building and other objects and their use for extraction of terrain parameters are fundamental. However, development of a suitable technique, to incorporate terrain parameters from classified LIDAR data and Aerial Photograph, for sound modelling is a challenge. Determination of terrain parameters along various transmission paths of sound from sound source to a receiver becomes very complex in an urban environment due to the presence of varied and complex urban features. This paper presents a technique to identify the principal paths through which sound transmits from source to receiver. Further, the identified principal paths are incorporated inside the sound model for sound prediction. Techniques based on plane cutting and line tracing are developed for determining principal paths and terrain parameters, which use various information, e.g., building corner and edges, triangulated ground, tree points and locations of source and receiver. The techniques developed are validated through a field experiment. Finally efficacy of the proposed technique is demonstrated by developing a noise map for a test site.

Analysis of acoustic sound signal for ONB measurement

International Nuclear Information System (INIS)

Park, S. J.; Kim, H. I.; Han, K. Y.; Chai, H. T.; Park, C.

2003-01-01

The onset of nucleate boiling (ONB) was measured in a test fuel bundle composed of several fuel element simulators (FES) by analysing the aquatic sound signals. In order measure ONBs, a hydrophone, a pre-amplifier, and a data acquisition system to acquire/process the aquatic signal was prepared. The acoustic signal generated in the coolant is converted to the current signal through the microphone. When the signal is analyzed in the frequency domain, each sound signal can be identified according to its origin of sound source. As the power is increased to a certain degree, a nucleate boiling is started. The frequent formation and collapse of the void bubbles produce sound signal. By measuring this sound signal one can pinpoint the ONB. Since the signal characteristics is identical for different mass flow rates, this method can be applicable for ascertaining ONB

Using sound to modify fish behavior at power-production and water-control facilities: A workshop. Phase 2: Final report

International Nuclear Information System (INIS)

Carlson, T.J.; Popper, A.N.

1997-06-01

A workshop on ''''Use of Sound for Fish Protection at Power-Production and Water-Control Facilities'''' was held in Portland, Oregon on December 12--13, 1995. This workshop convened a 22-member panel of international experts from universities, industry, and government to share knowledge, questions, and ideas about using sound for fish guidance. Discussions involved in a broad range of indigenous migratory and resident fish species and fish-protection issues in river systems, with particular focus on the Columbia River Basin. Because the use of sound behavioral barriers for fish is very much in its infancy, the workshop was designed to address the many questions being asked by fishery managers and researchers about the feasibility and potential benefits of using sound to augment physical barriers for fish protection in the Columbia River system

Urban Sound Interfaces

DEFF Research Database (Denmark)

Breinbjerg, Morten

2012-01-01

This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live. In this pa......This paper draws on the theories of Michel de Certeau and Gaston Bachelard to discuss how media architecture, in the form of urban sound interfaces, can help us perceive the complexity of the spaces we inhabit, by exploring the history and the narratives of the places in which we live....... In this paper, three sound works are discussed in relation to the iPod, which is considered as a more private way to explore urban environments, and as a way to control the individual perception of urban spaces....

Urban sound energy reduction by means of sound barriers

Science.gov (United States)

Iordache, Vlad; Ionita, Mihai Vlad

2018-02-01

In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

Urban sound energy reduction by means of sound barriers

Directory of Open Access Journals (Sweden)

Iordache Vlad

2018-01-01

Full Text Available In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

Controlled Acoustic Bass System (CABS) A Method to Achieve Uniform Sound Field Distribution at Low Frequencies in Rectangular Rooms

DEFF Research Database (Denmark)

Celestinos, Adrian; Nielsen, Sofus Birkedal

2008-01-01

The sound field produced by loudspeakers at low frequencies in small- and medium-size rectangular listening rooms is highly nonuniform due to the multiple reflections and diffractions of sound on the walls and different objects in the room. A new method, called controlled acoustic bass system (CA......-frequency range. CABS has been simulated and measured in two different standard listening rooms with satisfactory results....

Analysis and Synthesis of Musical Instrument Sounds

Science.gov (United States)

Beauchamp, James W.

For synthesizing a wide variety of musical sounds, it is important to understand which acoustic properties of musical instrument sounds are related to specific perceptual features. Some properties are obvious: Amplitude and fundamental frequency easily control loudness and pitch. Other perceptual features are related to sound spectra and how they vary with time. For example, tonal "brightness" is strongly connected to the centroid or tilt of a spectrum. "Attack impact" (sometimes called "bite" or "attack sharpness") is strongly connected to spectral features during the first 20-100 ms of sound, as well as the rise time of the sound. Tonal "warmth" is connected to spectral features such as "incoherence" or "inharmonicity."

Reassessment of the hydrocarbons in Prince William Sound and the Gulf of Alaska : identifying the source using partial least squares

International Nuclear Information System (INIS)

Mudge, S.M.

2001-01-01

Since the Exxon Valdez oil spill in Prince William Sound, Alaska there has been much discussion regarding the clean-up and long term fate of the oil. There has also been debate regarding the origin of the background hydrocarbons present within Prince William Sound (PWS) and the Gulf of Alaska (GoA). There is evidence that background (pre-spill) hydrocarbons may come from either nearby coal deposits or from natural oil seeps and eroding source rocks in the region. This paper presented a study in which the multivariate statistical methodology of the Partial Least Squares (PLS) was used to reassess the percentage contribution of coal, seep oil, shales and rivers to the hydrocarbon loading in the GoA. Data was provided by researchers at the National Ocean and Atmospheric Administration (NOAA) and the Bowdoin College, for Exxon. The data was analysed using selected sites as sources in order to develop signatures. The signatures were based on 40 and 136 compounds respectively, including the polyaromatic hydrocarbon (PAH) and terpane biomarkers from the Exxon data. The key components describing the sources were fitted to the data for other sites around the GoA to determine the proportion of the variability described by each source. The large complex datasets can be used to develop complex fingerprints for sources rather than using relatively simplistic ratios between selected compounds. The results indicate that 30 per cent of the signature is common between each source and that the small PAHs are the best diagnostic compounds in the model for the oil signature and the large PAHs are good for coal. Naphthalene, methyl and dimethyl naphthalene are the best markers for the seep oil signature. For the pre-spill background, coals and shales are best defined by the larger PAHs such as perylene and benzo(ghi)perylene. In general, the average partitioning between the two sources across all the sampling sites within the region indicated that 53 per cent is attributable to the

Improving Robustness against Environmental Sounds for Directing Attention of Social Robots

DEFF Research Database (Denmark)

Thomsen, Nicolai Bæk; Tan, Zheng-Hua; Lindberg, Børge

2015-01-01

This paper presents a multi-modal system for finding out where to direct the attention of a social robot in a dialog scenario, which is robust against environmental sounds (door slamming, phone ringing etc.) and short speech segments. The method is based on combining voice activity detection (VAD......) and sound source localization (SSL) and furthermore apply post-processing to SSL to filter out short sounds. The system is tested against a baseline system in four different real-world experiments, where different sounds are used as interfering sounds. The results are promising and show a clear improvement....

Promoting environmentally sound management of polybrominated diphenyl ethers in Asia.

Science.gov (United States)

Li, Jinhui; Zhao, Nana; Liu, Xue; Wu, Xiaoyang

2014-06-01

Polybrominated diphenyl ethers with persistent organic pollutant properties are required to be controlled by the Stockholm Convention. Recently, polybrominated diphenyl ether contamination has become widespread in Asia, mainly because of the disposal and recycling processes of polybrominated diphenyl ether-containing wastes. The management status, production, usage, import/export, treatment, and disposal, as well as implementation deficiencies for the environmentally sound management of polybrominated diphenyl ethers and polybrominated diphenyl ether-containing materials in ten Asian countries were investigated and assessed in this study. This information could help the participating countries implement the Stockholm Convention and could promote the regional environmentally sound management of polybrominated diphenyl ether-containing articles and products. The results obtained were as follows. (1) Most of the countries studied lacked environmental policies and regulations, or even standards of polybrominated diphenyl ether pollution management and emission control actions. Accurate data on the consumption and importation of polybrominated diphenyl ether-containing materials, however, were not available for all the participating countries. In addition, there were no special treatment or disposal systems for polybrominated diphenyl ether-containing materials, or emission-cutting measures for the treatment of waste in these countries, owing to the lack of sufficient funding or technologies. (2) The improper dismantling of e-waste is a major source of polybrominated diphenyl ether emissions in these countries. (3) Proper e-waste management could result in a breakthrough in the environmentally sound management of this major polybrominated diphenyl ether-containing material flow, and could significantly reduce polybrominated diphenyl ether emissions. Finally, based on the study results, this article puts forward some recommendations for improving the environmentally

Realtime synthesized sword-sounds in Wii computer games

DEFF Research Database (Denmark)

Böttcher, Niels

This paper presents the current work carried out on an interactive sword fighting game, developed for the Wii controller. The aim of the work is to develop highly interactive action-sound, which is closely mapped to the physical actions of the player. The interactive sword sound is developed using...... a combination of granular synthesis and subtractive synthesis simulating wind. The aim of the work is to test if more interactive sound can affect the way humans interact physically with their body, when playing games with controllers such as the Wii remote....

Neutron generator tube ion source control

International Nuclear Information System (INIS)

Bridges, J.R.

1982-01-01

A system is claimed for controlling the output of a neutron generator tube of the deuterium-tritium accelerator type and having an ion source to produce sharply defined pulses of neutrons for well logging use. It comprises: means for inputting a relatively low voltage input control pulse having a leading edge and a trailing edge; means, responsive to the input control pulse, for producing a relatively high voltage ion source voltage pulse after receipt of the input pulse; and means, responsive to the input control pulse, for quenching, after receipt of the input pulse, the ion source control pulse, thereby providing a sharply time defined neutron output from the generator tube

Synthesis of Room Impulse Responses for Variable Source Characteristics

Directory of Open Access Journals (Sweden)

M. Kunkemoeller

2011-01-01

Full Text Available Every acoustic source, e.g. a speaker, a musical instrument or a loudspeaker, generally has a frequency dependent characteristic radiation pattern, which is preeminent at higher frequencies. Room acoustic measurements nowadays only account for omnidirectional source characteristics. This motivates a measurement method that is capable of obtaining room impulse responses for these specific radiation patterns by using a superposition approach of several measurements with technically well-defined sound sources. We propose a method based on measurements with a 12-channel independentlydriven dodecahedron loudspeaker array rotated by an automatically controlled turntable.Radiation patterns can be efficiently described with the use of spherical harmonics representation. We propose a method that uses this representation for the spherical loudspeaker array used for the measurements and the target radiation pattern to be used for the synthesis.We show validating results for a deterministic test sound source inside in a small lecture hall.

Sound topology, duality, coherence and wave-mixing an introduction to the emerging new science of sound

CERN Document Server

Deymier, Pierre

2017-01-01

This book offers an essential introduction to the notions of sound wave topology, duality, coherence and wave-mixing, which constitute the emerging new science of sound. It includes general principles and specific examples that illuminate new non-conventional forms of sound (sound topology), unconventional quantum-like behavior of phonons (duality), radical linear and nonlinear phenomena associated with loss and its control (coherence), and exquisite effects that emerge from the interaction of sound with other physical and biological waves (wave mixing).  The book provides the reader with the foundations needed to master these complex notions through simple yet meaningful examples. General principles for unraveling and describing the topology of acoustic wave functions in the space of their Eigen values are presented. These principles are then applied to uncover intrinsic and extrinsic approaches to achieving non-conventional topologies by breaking the time revers al symmetry of acoustic waves. Symmetry brea...

A Sound Therapy-Based Intervention to Expand the Auditory Dynamic Range for Loudness among Persons with Sensorineural Hearing Losses: A Randomized Placebo-Controlled Clinical Trial

Science.gov (United States)

Formby, Craig; Hawley, Monica L.; Sherlock, LaGuinn P.; Gold, Susan; Payne, JoAnne; Brooks, Rebecca; Parton, Jason M.; Juneau, Roger; Desporte, Edward J.; Siegle, Gregory R.

2015-01-01

The primary aim of this research was to evaluate the validity, efficacy, and generalization of principles underlying a sound therapy–based treatment for promoting expansion of the auditory dynamic range (DR) for loudness. The basic sound therapy principles, originally devised for treatment of hyperacusis among patients with tinnitus, were evaluated in this study in a target sample of unsuccessfully fit and/or problematic prospective hearing aid users with diminished DRs (owing to their elevated audiometric thresholds and reduced sound tolerance). Secondary aims included: (1) delineation of the treatment contributions from the counseling and sound therapy components to the full-treatment protocol and, in turn, the isolated treatment effects from each of these individual components to intervention success; and (2) characterization of the respective dynamics for full, partial, and control treatments. Thirty-six participants with bilateral sensorineural hearing losses and reduced DRs, which affected their actual or perceived ability to use hearing aids, were enrolled in and completed a placebo-controlled (for sound therapy) randomized clinical trial. The 2 × 2 factorial trial design was implemented with or without various assignments of counseling and sound therapy. Specifically, participants were assigned randomly to one of four treatment groups (nine participants per group), including: (1) group 1—full treatment achieved with scripted counseling plus sound therapy implemented with binaural sound generators; (2) group 2—partial treatment achieved with counseling and placebo sound generators (PSGs); (3) group 3—partial treatment achieved with binaural sound generators alone; and (4) group 4—a neutral control treatment implemented with the PSGs alone. Repeated measurements of categorical loudness judgments served as the primary outcome measure. The full-treatment categorical-loudness judgments for group 1, measured at treatment termination, were

Monitoring Anthropogenic Ocean Sound from Shipping Using an Acoustic Sensor Network and a Compressive Sensing Approach †

Science.gov (United States)

Harris, Peter; Philip, Rachel; Robinson, Stephen; Wang, Lian

2016-01-01

Monitoring ocean acoustic noise has been the subject of considerable recent study, motivated by the desire to assess the impact of anthropogenic noise on marine life. A combination of measuring ocean sound using an acoustic sensor network and modelling sources of sound and sound propagation has been proposed as an approach to estimating the acoustic noise map within a region of interest. However, strategies for developing a monitoring network are not well established. In this paper, considerations for designing a network are investigated using a simulated scenario based on the measurement of sound from ships in a shipping lane. Using models for the sources of the sound and for sound propagation, a noise map is calculated and measurements of the noise map by a sensor network within the region of interest are simulated. A compressive sensing algorithm, which exploits the sparsity of the representation of the noise map in terms of the sources, is used to estimate the locations and levels of the sources and thence the entire noise map within the region of interest. It is shown that although the spatial resolution to which the sound sources can be identified is generally limited, estimates of aggregated measures of the noise map can be obtained that are more reliable compared with those provided by other approaches. PMID:27011187

Assessing and optimizing infra-sound networks to monitor volcanic eruptions

International Nuclear Information System (INIS)

Tailpied, Dorianne

2016-01-01

Understanding infra-sound signals is essential to monitor compliance with the Comprehensive Nuclear-Test ban Treaty, and also to demonstrate the potential of the global monitoring infra-sound network for civil and scientific applications. The main objective of this thesis is to develop a robust tool to estimate and optimize the performance of any infra-sound network to monitor explosive sources such as volcanic eruptions. Unlike previous studies, the developed method has the advantage to consider realistic atmospheric specifications along the propagation path, source frequency and noise levels at the stations. It allows to predict the attenuation and the minimum detectable source amplitude. By simulating the performances of any infra-sound networks, it is then possible to define the optimal configuration of the network to monitor a specific region, during a given period. When carefully adding a station to the existing network, performance can be improved by a factor of 2. However, it is not always possible to complete the network. A good knowledge of detection capabilities at large distances is thus essential. To provide a more realistic picture of the performance, we integrate the atmospheric longitudinal variability along the infra-sound propagation path in our simulations. This thesis also contributes in providing a confidence index taking into account the uncertainties related to propagation and atmospheric models. At high frequencies, the error can reach 40 dB. Volcanic eruptions are natural, powerful and valuable calibrating sources of infra-sound, worldwide detected. In this study, the well instrumented volcanoes Yasur, in Vanuatu, and Etna, in Italy, offer a unique opportunity to validate our attenuation model. In particular, accurate comparisons between near-field recordings and far-field detections of these volcanoes have helped to highlight the potential of our simulation tool to remotely monitor volcanoes. Such work could significantly help to prevent

On Sound: Reconstructing a Zhuangzian Perspective of Music

Directory of Open Access Journals (Sweden)

So Jeong Park

2015-12-01

Full Text Available A devotion to music in Chinese classical texts is worth noticing. Early Chinese thinkers saw music as a significant part of human experience and a core practice for philosophy. While Confucian endorsement of ritual and music has been discussed in the field, Daoist understanding of music was hardly explored. This paper will make a careful reading of the Xiánchí 咸池 music story in the Zhuangzi, one of the most interesting, but least noticed texts, and reconstruct a Zhuangzian perspective from it. While sounds had been regarded as mere building blocks of music and thus depreciated in the hierarchical understanding of music in the mainstream discourse of early China, sound is the alpha and omega of music in the Zhuangzian perspective. All kinds of sounds, both human and natural, are invited into musical discourse. Sound is regarded as the real source of our being moved by music, and therefore, musical consummation is depicted as embodiment through sound.

The propagation of sound in narrow street canyons

Science.gov (United States)

Iu, K. K.; Li, K. M.

2002-08-01

This paper addresses an important problem of predicting sound propagation in narrow street canyons with width less than 10 m, which are commonly found in a built-up urban district. Major noise sources are, for example, air conditioners installed on building facades and powered mechanical equipment for repair and construction work. Interference effects due to multiple reflections from building facades and ground surfaces are important contributions in these complex environments. Although the studies of sound transmission in urban areas can be traced back to as early as the 1960s, the resulting mathematical and numerical models are still unable to predict sound fields accurately in city streets. This is understandable because sound propagation in city streets involves many intriguing phenomena such as reflections and scattering at the building facades, diffusion effects due to recessions and protrusions of building surfaces, geometric spreading, and atmospheric absorption. This paper describes the development of a numerical model for the prediction of sound fields in city streets. To simplify the problem, a typical city street is represented by two parallel reflecting walls and a flat impedance ground. The numerical model is based on a simple ray theory that takes account of multiple reflections from the building facades. The sound fields due to the point source and its images are summed coherently such that mutual interference effects between contributing rays can be included in the analysis. Indoor experiments are conducted in an anechoic chamber. Experimental data are compared with theoretical predictions to establish the validity and usefulness of this simple model. Outdoor experimental measurements have also been conducted to further validate the model. copyright 2002 Acoustical Society of America.

The relationship between target quality and interference in sound zones

DEFF Research Database (Denmark)

Baykaner, Khan; Coleman, Phillip; Mason, Russell

2015-01-01

Sound zone systems aim to control sound fields in such a way that multiple listeners can enjoy different audio programs within the same room with minimal acoustic interference. Often, there is a trade-off between the acoustic contrast achieved between the zones and the fidelity of the reproduced...... audio program in the target zone. A listening test was conducted to obtain subjective measures of distraction, target quality, and overall quality of listening experience for ecologically valid programs within a sound zoning system. Sound zones were reproduced using acoustic contrast control, planarity...

The meaning of city noises: Investigating sound quality in Paris (France)

Science.gov (United States)

Dubois, Daniele; Guastavino, Catherine; Maffiolo, Valerie; Guastavino, Catherine; Maffiolo, Valerie

2004-05-01

The sound quality of Paris (France) was investigated by using field inquiries in actual environments (open questionnaires) and using recordings under laboratory conditions (free-sorting tasks). Cognitive categories of soundscapes were inferred by means of psycholinguistic analyses of verbal data and of mathematical analyses of similarity judgments. Results show that auditory judgments mainly rely on source identification. The appraisal of urban noise therefore depends on the qualitative evaluation of noise sources. The salience of human sounds in public spaces has been demonstrated, in relation to pleasantness judgments: soundscapes with human presence tend to be perceived as more pleasant than soundscapes consisting solely of mechanical sounds. Furthermore, human sounds are qualitatively processed as indicators of human outdoor activities, such as open markets, pedestrian areas, and sidewalk cafe districts that reflect city life. In contrast, mechanical noises (mainly traffic noise) are commonly described in terms of physical properties (temporal structure, intensity) of a permanent background noise that also characterizes urban areas. This connotes considering both quantitative and qualitative descriptions to account for the diversity of cognitive interpretations of urban soundscapes, since subjective evaluations depend both on the meaning attributed to noise sources and on inherent properties of the acoustic signal.

Neuromorphic Audio-Visual Sensor Fusion on a Sound-Localising Robot

Directory of Open Access Journals (Sweden)

Vincent Yue-Sek Chan

2012-02-01

Full Text Available This paper presents the first robotic system featuring audio-visual sensor fusion with neuromorphic sensors. We combine a pair of silicon cochleae and a silicon retina on a robotic platform to allow the robot to learn sound localisation through self-motion and visual feedback, using an adaptive ITD-based sound localisation algorithm. After training, the robot can localise sound sources (white or pink noise in a reverberant environment with an RMS error of 4 to 5 degrees in azimuth. In the second part of the paper, we investigate the source binding problem. An experiment is conducted to test the effectiveness of matching an audio event with a corresponding visual event based on their onset time. The results show that this technique can be quite effective, despite its simplicity.

Regulatory Control of Radioactive Sources in Spain

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, M.; Martin, J.L., E-mail: mrm@csn.es [Nuclear Safety Council, Madrid (Spain)

2011-07-15

The arrangements for the regulatory control of the safety and security of sealed radioactive sources in Spain are described. Emphasis is given to the situations which are most likely to result in the loss of control of sources and on the procedures introduced to reduce the likelihood of losses in these cases. Finally, the strategy for locating sources which have been lost from control (orphan sources) is described. (author)

Sound algorithms

OpenAIRE

De Götzen , Amalia; Mion , Luca; Tache , Olivier

2007-01-01

International audience; We call sound algorithms the categories of algorithms that deal with digital sound signal. Sound algorithms appeared in the very infancy of computer. Sound algorithms present strong specificities that are the consequence of two dual considerations: the properties of the digital sound signal itself and its uses, and the properties of auditory perception.

Sound transmission reduction with intelligent panel systems

Science.gov (United States)

Fuller, Chris R.; Clark, Robert L.

1992-01-01

Experimental and theoretical investigations are performed of the use of intelligent panel systems to control the sound transmission and radiation. An intelligent structure is defined as a structural system with integrated actuators and sensors under the guidance of an adaptive, learning type controller. The system configuration is based on the Active Structural Acoustic Control (ASAC) concept where control inputs are applied directly to the structure to minimize an error quantity related to the radiated sound field. In this case multiple piezoelectric elements are employed as sensors. The importance of optimal shape and location is demonstrated to be of the same order of influence as increasing the number of channels of control.

Control system for Siam photon source

CERN Document Server

Apiwatwaja, R; Isoyama, G; Ishii, T; Pairsuwan, W

2003-01-01

A new computer control system has been developed for Siam photon source, which is the first synchrotron light source in Thailand, personal computers and PLC's have been employed which are connected together through Ethernet. Man Machine Interface Stations (MMIS) at the front end act as a graphical user interface within Windows environment. The monitoring and controlling of individual devices is handled through several pairs of digital control station and the device interface located in each part of the synchrotron complex. The installation of the control system has been completed. The commissioning test of the control system is underway and the reliability of the system is on the positive side. Details of commissioning tests as well as characteristics of this newly built control system for the Siam photon source are described in this report.

46 CFR 7.20 - Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and...

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island Sound and easterly entrance to Long Island Sound, NY. 7.20 Section 7.20... Atlantic Coast § 7.20 Nantucket Sound, Vineyard Sound, Buzzards Bay, Narragansett Bay, MA, Block Island...

Second sound tracking system

Science.gov (United States)

Yang, Jihee; Ihas, Gary G.; Ekdahl, Dan

2017-10-01

It is common that a physical system resonates at a particular frequency, whose frequency depends on physical parameters which may change in time. Often, one would like to automatically track this signal as the frequency changes, measuring, for example, its amplitude. In scientific research, one would also like to utilize the standard methods, such as lock-in amplifiers, to improve the signal to noise ratio. We present a complete He ii second sound system that uses positive feedback to generate a sinusoidal signal of constant amplitude via automatic gain control. This signal is used to produce temperature/entropy waves (second sound) in superfluid helium-4 (He ii). A lock-in amplifier limits the oscillation to a desirable frequency and demodulates the received sound signal. Using this tracking system, a second sound signal probed turbulent decay in He ii. We present results showing that the tracking system is more reliable than those of a conventional fixed frequency method; there is less correlation with temperature (frequency) fluctuation when the tracking system is used.

Power conversion and control methods for renewable energy sources

Science.gov (United States)

Yu, Dachuan

2005-07-01

In recent years, there has been an increase in the use of renewable energy due to the growing concern over the pollution caused by fossil-fuel-based energy. Renewable energy sources, such as photovoltaic (PV) and fuel cell, can be used to enhance the safety, reliability, sustainability, and transmission efficiency of a power system. This dissertation focuses on the power conversion and control for two major renewable-energy sources: PV and fuel cell. Firstly, a current-based, maximum power-point tracking (MPPT) algorithm is proposed for PV energy. An economical converter system using the above scheme for converting the output from PV panels into 60 Hz AC voltage is developed and built. Secondly, a novel circuit model for the Proton Exchange Membrane (PEM) fuel-cell stack that is useful in the design and analysis of fuel-cell-based power systems is proposed. This Pspice-based model uses elements available in the Pspice library with some modifications to represent both the static and dynamic responses of a PEM fuel-cell module. The accuracy of the model is verified by comparing the simulation and experimental results. Thirdly, a DSP-controlled three-phase induction-motor drive using constant voltage over frequency is built and can be used in a fuel-cell automobile. A hydrogen sensor is used in the drive to both sound an alarm and shut down the inverter trigger pulses through the DSP. Finally, a hybrid power system consisting of PV panels and fuel cell is proposed and built. In the proposed system, PV panels can supply most of the power when the sunlight is available, and the excess power required by the load is supplied by a fuel cell. Load sharing between a fuel cell (FC) and the PV panel is investigated by both simulation and experiments.

Aerodynamic sound of flow past an airfoil

Science.gov (United States)

Wang, Meng

1995-01-01

The long term objective of this project is to develop a computational method for predicting the noise of turbulence-airfoil interactions, particularly at the trailing edge. We seek to obtain the energy-containing features of the turbulent boundary layers and the near-wake using Navier-Stokes Simulation (LES or DNS), and then to calculate the far-field acoustic characteristics by means of acoustic analogy theories, using the simulation data as acoustic source functions. Two distinct types of noise can be emitted from airfoil trailing edges. The first, a tonal or narrowband sound caused by vortex shedding, is normally associated with blunt trailing edges, high angles of attack, or laminar flow airfoils. The second source is of broadband nature arising from the aeroacoustic scattering of turbulent eddies by the trailing edge. Due to its importance to airframe noise, rotor and propeller noise, etc., trailing edge noise has been the subject of extensive theoretical (e.g. Crighton & Leppington 1971; Howe 1978) as well as experimental investigations (e.g. Brooks & Hodgson 1981; Blake & Gershfeld 1988). A number of challenges exist concerning acoustic analogy based noise computations. These include the elimination of spurious sound caused by vortices crossing permeable computational boundaries in the wake, the treatment of noncompact source regions, and the accurate description of wave reflection by the solid surface and scattering near the edge. In addition, accurate turbulence statistics in the flow field are required for the evaluation of acoustic source functions. Major efforts to date have been focused on the first two challenges. To this end, a paradigm problem of laminar vortex shedding, generated by a two dimensional, uniform stream past a NACA0012 airfoil, is used to address the relevant numerical issues. Under the low Mach number approximation, the near-field flow quantities are obtained by solving the incompressible Navier-Stokes equations numerically at chord

First results from experiment in South China Sea using marine controlled source electromagnetic

Science.gov (United States)

Li, Yuan; Wang, Lipeng; Deng, Ming

2016-04-01

We concentrated on the use of marine controlled-source electromagnetic (CSEM) sounding with a horizontal electric dipole source towed close to the seafloor and receivers anchored on the seafloor. We applied the CSEM method in South China Sea for the first time in 2014, which not only test the application of our instrument, but also test our data processing method. Electromagnetic fields transmitted by a towed electric dipole source in deep sea were measured by a linear array of six seafloor receivers, positioned 600 meter (m) apart. Our results provided two highly resistivity layers beneath the survey line and the gas hydrate saturation profile associated with the anomalous resistivity. In the letter, we discussed some anomalous layers during the interpretation steps. The most plausible explanation of the first resistivity layer anomalies is that large amounts of gas hydrate have accumulated at 200 m depth below the seep sites, and the second layers is considerable volumes of gas hydrate have accumulated the seafloor at survey line according to the conceptual model, during the resistivity compared with other evidence like seismic and well data from the same survey. We should try other observation like heat flow, geochemical or other evidence to test the statement in the future.

Sound Beams with Shockwave Pulses

Science.gov (United States)

Enflo, B. O.

2000-11-01

The beam equation for a sound beam in a diffusive medium, called the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, has a class of solutions, which are power series in the transverse variable with the terms given by a solution of a generalized Burgers’ equation. A free parameter in this generalized Burgers’ equation can be chosen so that the equation describes an N-wave which does not decay. If the beam source has the form of a spherical cap, then a beam with a preserved shock can be prepared. This is done by satisfying an inequality containing the spherical radius, the N-wave pulse duration, the N-wave pulse amplitude, and the sound velocity in the fluid.

Interpretation of time-domain electromagnetic soundings in the Calico Hills area, Nevada Test Site, Nye County, Nevada

Science.gov (United States)

Kauahikaua, J.

A controlled source, time domain electromagnetic (TDEM) sounding survey was conducted in the Calico Hills area of the Nevada Test Site (NTS). The geoelectric structure was determined as an aid in the evaluation of the site for possible future storage of spent nuclear fuel or high level nuclear waste. The data were initially interpreted with a simple scheme that produces an apparent resistivity versus depth curve from the vertical magnetic field data. These curves are qualitatively interpreted much like standard Schlumberger resistivity sounding curves. Final interpretation made use of a layered earth Marquardt inversion computer program. The results combined with those from a set of Schlumberger soundings in the area show that there is a moderately resistive basement at a depth no greater than 800 meters. The basement resistivity is greater than 100 ohm meters.

Evaluative conditioning induces changes in sound valence

Directory of Open Access Journals (Sweden)

Anna C. Bolders

2012-04-01

Full Text Available Evaluative Conditioning (EC has hardly been tested in the auditory domain, but it is a potentially valuable research tool. In Experiment 1 we investigated whether the affective evaluation of short environmental sounds can be changed using affective words as unconditioned stimuli (US. Congruence effects on an affective priming task (APT for conditioned sounds demonstrated successful EC. Subjective ratings for sounds paired with negative words changed accordingly. In Experiment 2 we investigated whether the acquired valence remains stable after repeated presentation of the conditioned sound without the US or whether extinction occurs. The acquired affective value remained present, albeit weaker, even after 40 extinction trials. These results warrant the use of EC to study processing of short environmental sounds with acquired valence, even if this requires repeated stimulus presentations. This paves the way for studying processing of affective environmental sounds while effectively controlling low level-stimulus properties.

Speed of sound measurements of liquid C1–C4 alkanols

International Nuclear Information System (INIS)

Dávila, María J.; Gedanitz, Holger; Span, Roland

2016-01-01

Highlights: • Speeds of sound in alkanols were measured in a wide temperature and pressure range. • A pulse-echo method with a double path type sensor was employed. • A double polynomial equation was used to fit the experimental speed of sound data. • The accurate results were compared with available literature sources. - Abstract: Speed of sound measurements were made in methanol, ethanol, propan-1-ol, and butan-1-ol in the temperature range from (253.15 to 353.15) K at pressures up to 30 MPa by use of a pulse-echo method with a double path type sensor. The expanded overall uncertainty (k = 2) in speed of sound measurements are estimated to be 0.026% for methanol, 0.03% for ethanol, 0.013% for propan-1-ol and 0.01% for butan-1-ol. A double polynomial equation for the speed of sound with inputs of temperature and pressure has been fitted from the experimental results. These were compared with available literature sources and fundamental equations of state, showing good agreement among them to comparable alcohol purities and experimental uncertainties.

Neural Decoding of Bistable Sounds Reveals an Effect of Intention on Perceptual Organization.

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Billig, Alexander J; Davis, Matthew H; Carlyon, Robert P

2018-03-14

Auditory signals arrive at the ear as a mixture that the brain must decompose into distinct sources based to a large extent on acoustic properties of the sounds. An important question concerns whether listeners have voluntary control over how many sources they perceive. This has been studied using pure high (H) and low (L) tones presented in the repeating pattern HLH-HLH-, which can form a bistable percept heard either as an integrated whole (HLH-) or as segregated into high (H-H-) and low (-L-) sequences. Although instructing listeners to try to integrate or segregate sounds affects reports of what they hear, this could reflect a response bias rather than a perceptual effect. We had human listeners (15 males, 12 females) continuously report their perception of such sequences and recorded neural activity using MEG. During neutral listening, a classifier trained on patterns of neural activity distinguished between periods of integrated and segregated perception. In other conditions, participants tried to influence their perception by allocating attention either to the whole sequence or to a subset of the sounds. They reported hearing the desired percept for a greater proportion of time than when listening neutrally. Critically, neural activity supported these reports; stimulus-locked brain responses in auditory cortex were more likely to resemble the signature of segregation when participants tried to hear segregation than when attempting to perceive integration. These results indicate that listeners can influence how many sound sources they perceive, as reflected in neural responses that track both the input and its perceptual organization. SIGNIFICANCE STATEMENT Can we consciously influence our perception of the external world? We address this question using sound sequences that can be heard either as coming from a single source or as two distinct auditory streams. Listeners reported spontaneous changes in their perception between these two interpretations while

Effects of interaural level differences on the externalization of sound

DEFF Research Database (Denmark)

Catic, Jasmina; Santurette, Sébastien; Dau, Torsten

2012-01-01

Distant sound sources in our environment are perceived as externalized and are thus properly localized in both direction and distance. This is due to the acoustic filtering by the head, torso, and external ears, which provides frequency-dependent shaping of binaural cues such as interaural level...... differences (ILDs) and interaural time differences (ITDs). In rooms, the sound reaching the two ears is further modified by reverberant energy, which leads to increased fluctuations in short-term ILDs and ITDs. In the present study, the effect of ILD fluctuations on the externalization of sound......, for sounds that contain frequencies above about 1 kHz the ILD fluctuations were found to be an essential cue for externalization....

Externalization versus Internalization of Sound in Normal-hearing and Hearing-impaired Listeners

DEFF Research Database (Denmark)

Ohl, Björn; Laugesen, Søren; Buchholz, Jörg

2010-01-01

The externalization of sound, i. e. the perception of auditory events as being located outside of the head, is a natural phenomenon for normalhearing listeners, when perceiving sound coming from a distant physical sound source. It is potentially useful for hearing in background noise......, but the relevant cues might be distorted by a hearing impairment and also by the processing of the incoming sound through hearing aids. In this project, two intuitive tests in natural real-life surroundings were developed, which capture the limits of the perception of externalization. For this purpose...

Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A): Instrumentation interface control document

Science.gov (United States)

1994-01-01

This Interface Control Document (ICD) defines the specific details of the complete accomodation information between the Earth Observing System (EOS) PM Spacecraft and the Advanced Microwave Sounding Unit (AMSU-A)Instrument. This is the first submittal of the ICN: it will be updated periodically throughout the life of the program. The next update is planned prior to Critical Design Review (CDR).

Mercury in Long Island Sound sediments

Science.gov (United States)

Varekamp, J.C.; Buchholtz ten Brink, Marilyn R.; Mecray, E.I.; Kreulen, B.

2000-01-01

Mercury (Hg) concentrations were measured in 394 surface and core samples from Long Island Sound (LIS). The surface sediment Hg concentration data show a wide spread, ranging from 600 ppb Hg in westernmost LIS. Part of the observed range is related to variations in the bottom sedimentary environments, with higher Hg concentrations in the muddy depositional areas of central and western LIS. A strong residual trend of higher Hg values to the west remains when the data are normalized to grain size. Relationships between a tracer for sewage effluents (C. perfringens) and Hg concentrations indicate that between 0-50 % of the Hg is derived from sewage sources for most samples from the western and central basins. A higher percentage of sewage-derived Hg is found in samples from the westernmost section of LIS and in some local spots near urban centers. The remainder of the Hg is carried into the Sound with contaminated sediments from the watersheds and a small fraction enters the Sound as in situ atmospheric deposition. The Hg-depth profiles of several cores have well-defined contamination profiles that extend to pre-industrial background values. These data indicate that the Hg levels in the Sound have increased by a factor of 5-6 over the last few centuries, but Hg levels in LIS sediments have declined in modern times by up to 30 %. The concentrations of C. perfringens increased exponentially in the top core sections which had declining Hg concentrations, suggesting a recent decline in Hg fluxes that are unrelated to sewage effluents. The observed spatial and historical trends show Hg fluxes to LIS from sewage effluents, contaminated sediment input from the Connecticut River, point source inputs of strongly contaminated sediment from the Housatonic River, variations in the abundance of Hg carrier phases such as TOC and Fe, and focusing of sediment-bound Hg in association with westward sediment transport within the Sound.

Xinyinqin: a computer-based heart sound simulator.

Science.gov (United States)

Zhan, X X; Pei, J H; Xiao, Y H

1995-01-01

"Xinyinqin" is the Chinese phoneticized name of the Heart Sound Simulator (HSS). The "qin" in "Xinyinqin" is the Chinese name of a category of musical instruments, which means that the operation of HSS is very convenient--like playing an electric piano with the keys. HSS is connected to the GAME I/O of an Apple microcomputer. The generation of sound is controlled by a program. Xinyinqin is used as a teaching aid of Diagnostics. It has been applied in teaching for three years. In this demonstration we will introduce the following functions of HSS: 1) The main program has two modules. The first one is the heart auscultation training module. HSS can output a heart sound selected by the student. Another program module is used to test the student's learning condition. The computer can randomly simulate a certain heart sound and ask the student to name it. The computer gives the student's answer an assessment: "correct" or "incorrect." When the answer is incorrect, the computer will output that heart sound again for the student to listen to; this process is repeated until she correctly identifies it. 2) The program is convenient to use and easy to control. By pressing the S key, it is able to output a slow heart rate until the student can clearly identify the rhythm. The heart rate, like the actual rate of a patient, can then be restored by hitting any key. By pressing the SPACE BAR, the heart sound output can be stopped to allow the teacher to explain something to the student. The teacher can resume playing the heart sound again by hitting any key; she can also change the content of the training by hitting RETURN key. In the future, we plan to simulate more heart sounds and incorporate relevant graphs.

Sound and heat revolutions in phononics

Science.gov (United States)

Maldovan, Martin

2013-11-01

The phonon is the physical particle representing mechanical vibration and is responsible for the transmission of everyday sound and heat. Understanding and controlling the phononic properties of materials provides opportunities to thermally insulate buildings, reduce environmental noise, transform waste heat into electricity and develop earthquake protection. Here I review recent progress and the development of new ideas and devices that make use of phononic properties to control both sound and heat. Advances in sonic and thermal diodes, optomechanical crystals, acoustic and thermal cloaking, hypersonic phononic crystals, thermoelectrics, and thermocrystals herald the next technological revolution in phononics.

The sound field of a rotating dipole in a plug flow.

Science.gov (United States)

Wang, Zhao-Huan; Belyaev, Ivan V; Zhang, Xiao-Zheng; Bi, Chuan-Xing; Faranosov, Georgy A; Dowell, Earl H

2018-04-01

An analytical far field solution for a rotating point dipole source in a plug flow is derived. The shear layer of the jet is modelled as an infinitely thin cylindrical vortex sheet and the far field integral is calculated by the stationary phase method. Four numerical tests are performed to validate the derived solution as well as to assess the effects of sound refraction from the shear layer. First, the calculated results using the derived formulations are compared with the known solution for a rotating dipole in a uniform flow to validate the present model in this fundamental test case. After that, the effects of sound refraction for different rotating dipole sources in the plug flow are assessed. Then the refraction effects on different frequency components of the signal at the observer position, as well as the effects of the motion of the source and of the type of source are considered. Finally, the effect of different sound speeds and densities outside and inside the plug flow is investigated. The solution obtained may be of particular interest for propeller and rotor noise measurements in open jet anechoic wind tunnels.

Noise and noise disturbances from wind power plants - Tests with interactive control of sound parameters for more comfortable and less perceptible sounds

International Nuclear Information System (INIS)

Persson-Waye, K.; Oehrstroem, E.; Bjoerkman, M.; Agge, A.

2001-12-01

In experimental pilot studies, a methodology has been worked out for interactively varying sound parameters in wind power plants. In the tests, 24 persons varied the center frequency of different band-widths, the frequency of a sinus-tone and the amplitude-modulation of a sinus-tone in order to create as comfortable a sound as possible. The variations build on the noise from the two wind turbines Bonus and Wind World. The variations were performed with a constant dba level. The results showed that the majority preferred a low-frequency tone (94 Hz and 115 Hz for Wind World and Bonus, respectively). The mean of the most comfortable amplitude-modulation varied between 18 and 22 Hz, depending on the ground frequency. The mean of the center-frequency for the different band-widths varied from 785 to 1104 Hz. In order to study the influence of the wind velocity on the acoustic character of the noise, a long-time measurement program has been performed. A remotely controlled system has been developed, where wind velocity, wind direction, temperature and humidity are registered simultaneously with the noise. Long-time registrations have been performed for four different wing turbines

On the sound insulation of acoustic metasurface using a sub-structuring approach

Science.gov (United States)

Yu, Xiang; Lu, Zhenbo; Cheng, Li; Cui, Fangsen

2017-08-01

The feasibility of using an acoustic metasurface (AMS) with acoustic stop-band property to realize sound insulation with ventilation function is investigated. An efficient numerical approach is proposed to evaluate its sound insulation performance. The AMS is excited by a reverberant sound source and the standardized sound reduction index (SRI) is numerically investigated. To facilitate the modeling, the coupling between the AMS and the adjacent acoustic fields is formulated using a sub-structuring approach. A modal based formulation is applied to both the source and receiving room, enabling an efficient calculation in the frequency range from 125 Hz to 2000 Hz. The sound pressures and the velocities at the interface are matched by using a transfer function relation based on ;patches;. For illustration purposes, numerical examples are investigated using the proposed approach. The unit cell constituting the AMS is constructed in the shape of a thin acoustic chamber with tailored inner structures, whose stop-band property is numerically analyzed and experimentally demonstrated. The AMS is shown to provide effective sound insulation of over 30 dB in the stop-band frequencies from 600 to 1600 Hz. It is also shown that the proposed approach has the potential to be applied to a broad range of AMS studies and optimization problems.

Sound produced by an oscillating arc in a high-pressure gas

Science.gov (United States)

Popov, Fedor K.; Shneider, Mikhail N.

2017-08-01

We suggest a simple theory to describe the sound generated by small periodic perturbations of a cylindrical arc in a dense gas. Theoretical analysis was done within the framework of the non-self-consistent channel arc model and supplemented with time-dependent gas dynamic equations. It is shown that an arc with power amplitude oscillations on the order of several percent is a source of sound whose intensity is comparable with external ultrasound sources used in experiments to increase the yield of nanoparticles in the high pressure arc systems for nanoparticle synthesis.

Multichannel sound reinforcement systems at work in a learning environment

Science.gov (United States)

Malek, John; Campbell, Colin

2003-04-01

Many people have experienced the entertaining benefits of a surround sound system, either in their own home or in a movie theater, but another application exists for multichannel sound that has for the most part gone unused. This is the application of multichannel sound systems to the learning environment. By incorporating a 7.1 surround processor and a touch panel interface programmable control system, the main lecture hall at the University of Michigan Taubman College of Architecture and Urban Planning has been converted from an ordinary lecture hall to a working audiovisual laboratory. The multichannel sound system is used in a wide variety of experiments, including exposure to sounds to test listeners' aural perception of the tonal characteristics of varying pitch, reverberation, speech transmission index, and sound-pressure level. The touch panel's custom interface allows a variety of user groups to control different parts of the AV system and provides preset capability that allows for numerous system configurations.

Problems in nonlinear acoustics: Scattering of sound by sound, parametric receiving arrays, nonlinear effects in asymmetric sound beams and pulsed finite amplitude sound beams

Science.gov (United States)

Hamilton, Mark F.

1989-08-01

Four projects are discussed in this annual summary report, all of which involve basic research in nonlinear acoustics: Scattering of Sound by Sound, a theoretical study of two nonconlinear Gaussian beams which interact to produce sum and difference frequency sound; Parametric Receiving Arrays, a theoretical study of parametric reception in a reverberant environment; Nonlinear Effects in Asymmetric Sound Beams, a numerical study of two dimensional finite amplitude sound fields; and Pulsed Finite Amplitude Sound Beams, a numerical time domain solution of the KZK equation.

Acoustic Performance of a Real-Time Three-Dimensional Sound-Reproduction System

Science.gov (United States)

Faller, Kenneth J., II; Rizzi, Stephen A.; Aumann, Aric R.

2013-01-01

The Exterior Effects Room (EER) is a 39-seat auditorium at the NASA Langley Research Center and was built to support psychoacoustic studies of aircraft community noise. The EER has a real-time simulation environment which includes a three-dimensional sound-reproduction system. This system requires real-time application of equalization filters to compensate for spectral coloration of the sound reproduction due to installation and room effects. This paper describes the efforts taken to develop the equalization filters for use in the real-time sound-reproduction system and the subsequent analysis of the system s acoustic performance. The acoustic performance of the compensated and uncompensated sound-reproduction system is assessed for its crossover performance, its performance under stationary and dynamic conditions, the maximum spatialized sound pressure level it can produce from a single virtual source, and for the spatial uniformity of a generated sound field. Additionally, application examples are given to illustrate the compensated sound-reproduction system performance using recorded aircraft flyovers

High frequency source localization in a shallow ocean sound channel using frequency difference matched field processing.

Science.gov (United States)

Worthmann, Brian M; Song, H C; Dowling, David R

2015-12-01

Matched field processing (MFP) is an established technique for source localization in known multipath acoustic environments. Unfortunately, in many situations, particularly those involving high frequency signals, imperfect knowledge of the actual propagation environment prevents accurate propagation modeling and source localization via MFP fails. For beamforming applications, this actual-to-model mismatch problem was mitigated through a frequency downshift, made possible by a nonlinear array-signal-processing technique called frequency difference beamforming [Abadi, Song, and Dowling (2012). J. Acoust. Soc. Am. 132, 3018-3029]. Here, this technique is extended to conventional (Bartlett) MFP using simulations and measurements from the 2011 Kauai Acoustic Communications MURI experiment (KAM11) to produce ambiguity surfaces at frequencies well below the signal bandwidth where the detrimental effects of mismatch are reduced. Both the simulation and experimental results suggest that frequency difference MFP can be more robust against environmental mismatch than conventional MFP. In particular, signals of frequency 11.2 kHz-32.8 kHz were broadcast 3 km through a 106-m-deep shallow ocean sound channel to a sparse 16-element vertical receiving array. Frequency difference MFP unambiguously localized the source in several experimental data sets with average peak-to-side-lobe ratio of 0.9 dB, average absolute-value range error of 170 m, and average absolute-value depth error of 10 m.

PREFACE: Aerodynamic sound Aerodynamic sound

Science.gov (United States)

Akishita, Sadao

2010-02-01

The modern theory of aerodynamic sound originates from Lighthill's two papers in 1952 and 1954, as is well known. I have heard that Lighthill was motivated in writing the papers by the jet-noise emitted by the newly commercialized jet-engined airplanes at that time. The technology of aerodynamic sound is destined for environmental problems. Therefore the theory should always be applied to newly emerged public nuisances. This issue of Fluid Dynamics Research (FDR) reflects problems of environmental sound in present Japanese technology. The Japanese community studying aerodynamic sound has held an annual symposium since 29 years ago when the late Professor S Kotake and Professor S Kaji of Teikyo University organized the symposium. Most of the Japanese authors in this issue are members of the annual symposium. I should note the contribution of the two professors cited above in establishing the Japanese community of aerodynamic sound research. It is my pleasure to present the publication in this issue of ten papers discussed at the annual symposium. I would like to express many thanks to the Editorial Board of FDR for giving us the chance to contribute these papers. We have a review paper by T Suzuki on the study of jet noise, which continues to be important nowadays, and is expected to reform the theoretical model of generating mechanisms. Professor M S Howe and R S McGowan contribute an analytical paper, a valuable study in today's fluid dynamics research. They apply hydrodynamics to solve the compressible flow generated in the vocal cords of the human body. Experimental study continues to be the main methodology in aerodynamic sound, and it is expected to explore new horizons. H Fujita's study on the Aeolian tone provides a new viewpoint on major, longstanding sound problems. The paper by M Nishimura and T Goto on textile fabrics describes new technology for the effective reduction of bluff-body noise. The paper by T Sueki et al also reports new technology for the

Vulnerability to the Irrelevant Sound Effect in Adult ADHD.

Science.gov (United States)

Pelletier, Marie-France; Hodgetts, Helen M; Lafleur, Martin F; Vincent, Annick; Tremblay, Sébastien

2016-04-01

An ecologically valid adaptation of the irrelevant sound effect paradigm was employed to examine the relative roles of short-term memory, selective attention, and sustained attention in ADHD. In all, 32 adults with ADHD and 32 control participants completed a serial recall task in silence or while ignoring irrelevant background sound. Serial recall performance in adults with ADHD was reduced relative to controls in both conditions. The degree of interference due to irrelevant sound was greater for adults with ADHD. Furthermore, a positive correlation was observed between task performance under conditions of irrelevant sound and the extent of attentional problems reported by patients on a clinical symptom scale. The results demonstrate that adults with ADHD exhibit impaired short-term memory and a low resistance to distraction; however, their capacity for sustained attention is preserved as the impact of irrelevant sound diminished over the course of the task. © The Author(s) 2013.

Model predictive control for Z-source power converter

DEFF Research Database (Denmark)

Mo, W.; Loh, P.C.; Blaabjerg, Frede

2011-01-01

This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) power converter. Output voltage control and current control for Z-source inverter are analyzed and simulated. With MPC's ability of multi- system variables regulation, load current and voltage...

Submarine groundwater discharge driven nitrogen fluxes to Long Island Sound, NY: Terrestrial vs. marine sources

Science.gov (United States)

Tamborski, J. J.; Cochran, J. K.; Bokuniewicz, H. J.

2017-12-01

Bottom-waters in Smithtown Bay (Long Island Sound, NY) are subject to hypoxic conditions every summer despite limited nutrient inputs from waste-water and riverine sources, while modeling estimates of groundwater inputs are thought to be insignificant. Terrestrial and marine fluxes of submarine groundwater discharge (SGD) were quantified to Smithtown Bay using mass balances of 222Rn, 224Ra, 226Ra and 228Ra during the spring and summer of 2014/2015, in order to track this seasonal transition period. Intertidal pore waters from a coastal bluff (terrestrial SGD) and from a barrier beach (marine SGD) displayed substantial differences in N concentrations and sources, traced using a multi-isotope approach (222Rn, Ra, δ15N-NO3-, δ18O-NO3-). NO3- in terrestrial SGD did not display any seasonality and was derived from residential septic systems and fertilizer. Marine SGD N concentrations varied month-to-month because of mixing between oxic seawater and hypoxic saline pore waters; N concentrations were greatest during the summer, when NO3- was derived from the remineralization of organic matter. Short-lived 222Rn and 224Ra SGD fluxes were used to determine remineralized N loads along tidal recirculation flow paths, while long-lived 228Ra was used to trace inputs of anthropogenic N in terrestrial SGD. 228Ra-derived terrestrial N load estimates were between 20 and 55% lower than 224Ra-derived estimates (excluding spring 2014); 228Ra may be a more appropriate tracer of terrestrial SGD N loads. Terrestrial SGD NO3- (derived from 228Ra) to Smithtown Bay varied from (1.40-12.8) ∗ 106 mol N y-1, with comparable marine SGD NO3- fluxes of (1.70-6.79) ∗ 106 mol N y-1 derived from 222Rn and 224Ra. Remineralized N loads were greater during the summer compared with spring, and these may be an important driver toward the onset of seasonal hypoxic conditions in Smithtown Bay and western Long Island Sound. Seawater recirculation through the coastal aquifer can rival the N load from

Source splitting via the point source method

International Nuclear Information System (INIS)

Potthast, Roland; Fazi, Filippo M; Nelson, Philip A

2010-01-01

We introduce a new algorithm for source identification and field splitting based on the point source method (Potthast 1998 A point-source method for inverse acoustic and electromagnetic obstacle scattering problems IMA J. Appl. Math. 61 119–40, Potthast R 1996 A fast new method to solve inverse scattering problems Inverse Problems 12 731–42). The task is to separate the sound fields u j , j = 1, ..., n of n element of N sound sources supported in different bounded domains G 1 , ..., G n in R 3 from measurements of the field on some microphone array—mathematically speaking from the knowledge of the sum of the fields u = u 1 + ... + u n on some open subset Λ of a plane. The main idea of the scheme is to calculate filter functions g 1 ,…, g n , n element of N, to construct u l for l = 1, ..., n from u| Λ in the form u l (x) = ∫ Λ g l,x (y)u(y)ds(y), l=1,... n. (1) We will provide the complete mathematical theory for the field splitting via the point source method. In particular, we describe uniqueness, solvability of the problem and convergence and stability of the algorithm. In the second part we describe the practical realization of the splitting for real data measurements carried out at the Institute for Sound and Vibration Research at Southampton, UK. A practical demonstration of the original recording and the splitting results for real data is available online

Metrics for Polyphonic Sound Event Detection

Directory of Open Access Journals (Sweden)

Annamaria Mesaros

2016-05-01

Full Text Available This paper presents and discusses various metrics proposed for evaluation of polyphonic sound event detection systems used in realistic situations where there are typically multiple sound sources active simultaneously. The system output in this case contains overlapping events, marked as multiple sounds detected as being active at the same time. The polyphonic system output requires a suitable procedure for evaluation against a reference. Metrics from neighboring fields such as speech recognition and speaker diarization can be used, but they need to be partially redefined to deal with the overlapping events. We present a review of the most common metrics in the field and the way they are adapted and interpreted in the polyphonic case. We discuss segment-based and event-based definitions of each metric and explain the consequences of instance-based and class-based averaging using a case study. In parallel, we provide a toolbox containing implementations of presented metrics.

Development of Sound Localization Strategies in Children with Bilateral Cochlear Implants.

Directory of Open Access Journals (Sweden)

Yi Zheng

Full Text Available Localizing sounds in our environment is one of the fundamental perceptual abilities that enable humans to communicate, and to remain safe. Because the acoustic cues necessary for computing source locations consist of differences between the two ears in signal intensity and arrival time, sound localization is fairly poor when a single ear is available. In adults who become deaf and are fitted with cochlear implants (CIs sound localization is known to improve when bilateral CIs (BiCIs are used compared to when a single CI is used. The aim of the present study was to investigate the emergence of spatial hearing sensitivity in children who use BiCIs, with a particular focus on the development of behavioral localization patterns when stimuli are presented in free-field horizontal acoustic space. A new analysis was implemented to quantify patterns observed in children for mapping acoustic space to a spatially relevant perceptual representation. Children with normal hearing were found to distribute their responses in a manner that demonstrated high spatial sensitivity. In contrast, children with BiCIs tended to classify sound source locations to the left and right; with increased bilateral hearing experience, they developed a perceptual map of space that was better aligned with the acoustic space. The results indicate experience-dependent refinement of spatial hearing skills in children with CIs. Localization strategies appear to undergo transitions from sound source categorization strategies to more fine-grained location identification strategies. This may provide evidence for neural plasticity, with implications for training of spatial hearing ability in CI users.

Surface Deformation by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

Science.gov (United States)

Fuhrmann, Eckart; Dreyer, Michael E.

The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The scientific aims are to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat transfer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. Correlations for the effective contact angle and the heat transfer coefficient shall be delivered as a function of the relevant dimensionsless parameters. The data will be used for benchmarking of commercial CFD codes and the tank design

A comparison of two different sound intensity measurement principles

DEFF Research Database (Denmark)

Jacobsen, Finn; de Bree, Hans-Elias

2005-01-01

, and compares the two measurement principles with particular regard to the sources of error in sound power determination. It is shown that the phase calibration of intensity probes that combine different transducers is very critical below 500 Hz if the measurement surface is very close to the source under test...

Common sole larvae survive high levels of pile-driving sound in controlled exposure experiments

NARCIS (Netherlands)

Bolle, L.J.; Jong, C.A.F. de; Bierman, S.M.; Beek, P.J.G. van; Keeken, O.A. van; Wessels, P.W.; Damme, C.J.G. van; Winter, H.V.; Haan, D. de; Dekeling, R.P.A.

2012-01-01

In view of the rapid extension of offshore wind farms, there is an urgent need to improve our knowledge on possible adverse effects of underwater sound generated by pile-driving. Mortality and injuries have been observed in fish exposed to loud impulse sounds, but knowledge on the sound levels at

The IAEA and Control of Radioactive Sources

International Nuclear Information System (INIS)

Dodd, B.

2004-01-01

The presentation discusses the authoritative functions and the departments of the IAEA, especially the Department of Nuclear Safety and Security and its Safety and Security of Radiation Sources Unit. IAEA safety series and IAEA safety standards series inform about international standards, provide underlying principles, specify obligations and responsibilities and give recommendations to support requirements. Other IAEA relevant publications comprise safety reports, technical documents (TECDOCs), conferences and symposium papers series and accident reports. Impacts of loss of source control is discussed, definitions of orphan sources and vulnerable sources is given. Accidents with orphan sources, radiological accidents statistic (1944-2000) and its consequences are discussed. These incidents lead to development of the IAEA guidance. The IAEA's action plan for the safety of radiation sources and the security of radioactive material was approved by the IAEA Board of Governors and the General Conference in September 1999. This led to the 'Categorization of Radiation Sources' and the 'Code of Conduct on the Safety and Security of Radioactive Sources'. After 0911 the IAEA developed a nuclear security plan of activities including physical protection of nuclear material and nuclear facilities, detection of malicious activities involving nuclear and other radioactive materials, state systems for nuclear material accountancy and control, security of radioactive material other than nuclear material, assessment of safety and security related vulnerability of nuclear facilities, response to malicious acts, or threats thereof, adherence to and implementation of international agreements, guidelines and recommendations and nuclear security co-ordination and information management. The remediation of past problems comprised collection and disposal of known disused sources, securing vulnerable sources and especially high-risk sources (Tripartite initiative), searching for

Propagation of Finite Amplitude Sound in Multiple Waveguide Modes.

Science.gov (United States)

van Doren, Thomas Walter

1993-01-01

This dissertation describes a theoretical and experimental investigation of the propagation of finite amplitude sound in multiple waveguide modes. Quasilinear analytical solutions of the full second order nonlinear wave equation, the Westervelt equation, and the KZK parabolic wave equation are obtained for the fundamental and second harmonic sound fields in a rectangular rigid-wall waveguide. It is shown that the Westervelt equation is an acceptable approximation of the full nonlinear wave equation for describing guided sound waves of finite amplitude. A system of first order equations based on both a modal and harmonic expansion of the Westervelt equation is developed for waveguides with locally reactive wall impedances. Fully nonlinear numerical solutions of the system of coupled equations are presented for waveguides formed by two parallel planes which are either both rigid, or one rigid and one pressure release. These numerical solutions are compared to finite -difference solutions of the KZK equation, and it is shown that solutions of the KZK equation are valid only at frequencies which are high compared to the cutoff frequencies of the most important modes of propagation (i.e., for which sound propagates at small grazing angles). Numerical solutions of both the Westervelt and KZK equations are compared to experiments performed in an air-filled, rigid-wall, rectangular waveguide. Solutions of the Westervelt equation are in good agreement with experiment for low source frequencies, at which sound propagates at large grazing angles, whereas solutions of the KZK equation are not valid for these cases. At higher frequencies, at which sound propagates at small grazing angles, agreement between numerical solutions of the Westervelt and KZK equations and experiment is only fair, because of problems in specifying the experimental source condition with sufficient accuracy.

Development of Active Noise Control System for Quieting Transformer Noise

Energy Technology Data Exchange (ETDEWEB)

Lee, Bok Kyu; Song, Seik Young; Choi, Huo Yul [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Yun, Dae Hea; Lee, Hyuk Jae [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

1997-12-31

The passive noise control technique made use of sound-absorbing or soundproofing materials, so it required a large area and high cost for installation and had a drawback of poor performance at low frequency. Compared to this, the Active Noise Control attenuates noise sound pressure by using secondary source which has same performance ay low-frequency. Furthermore, it is able to save space and expenses. - research on adaptive algorithms - evaluation of global attenuation of the control - computer simulation - real-time Active Noise Control System Hardware Implementation - ANC system setting in the noisy area.

Prediction model for sound transmission from machinery in buildings: feasible approaches and problems to be solved

NARCIS (Netherlands)

Gerretsen, E.

2000-01-01

Prediction models for the airborne and impact sound transmission in buildings have recently been established (EN 12354- 1&2:1999). However, these models do not cover technical installations and machinery as a source of sound in buildings. Yet these can cause unacceptable sound levels and it is

Advanced Light Source control system

International Nuclear Information System (INIS)

Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

1989-03-01

The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs

Noise control, sound, and the vehicle design process

Science.gov (United States)

Donavan, Paul

2005-09-01

For many products, noise and sound are viewed as necessary evils that need to be dealt with in order to bring the product successfully to market. They are generally not product ``exciters'' although some vehicle manufacturers do tune and advertise specific sounds to enhance the perception of their products. In this paper, influencing the design process for the ``evils,'' such as wind noise and road noise, are considered in more detail. There are three ingredients to successfully dealing with the evils in the design process. The first of these is knowing how excesses in noise effects the end customer in a tangible manner and how that effects customer satisfaction and ultimately sells. The second is having and delivering the knowledge of what is required of the design to achieve a satisfactory or even better level of noise performance. The third ingredient is having the commitment of the designers to incorporate the knowledge into their part, subsystem or system. In this paper, the elements of each of these ingredients are discussed in some detail and the attributes of a successful design process are enumerated.

Near-field acoustic holography with sound pressure and particle velocity measurements

DEFF Research Database (Denmark)

Fernandez Grande, Efren

of the particle velocity has notable potential in NAH, and furthermore, combined measurement of sound pressure and particle velocity opens a new range of possibilities that are examined in this study. On this basis, sound field separation methods have been studied, and a new measurement principle based on double...... layer measurements of the particle velocity has been proposed. Also, the relation between near-field and far-field radiation from sound sources has been examined using the concept of the supersonic intensity. The calculation of this quantity has been extended to other holographic methods, and studied...

Interactive Sound Propagation using Precomputation and Statistical Approximations

Science.gov (United States)

Antani, Lakulish

Acoustic phenomena such as early reflections, diffraction, and reverberation have been shown to improve the user experience in interactive virtual environments and video games. These effects arise due to repeated interactions between sound waves and objects in the environment. In interactive applications, these effects must be simulated within a prescribed time budget. We present two complementary approaches for computing such acoustic effects in real time, with plausible variation in the sound field throughout the scene. The first approach, Precomputed Acoustic Radiance Transfer, precomputes a matrix that accounts for multiple acoustic interactions between all scene objects. The matrix is used at run time to provide sound propagation effects that vary smoothly as sources and listeners move. The second approach couples two techniques---Ambient Reverberance, and Aural Proxies---to provide approximate sound propagation effects in real time, based on only the portion of the environment immediately visible to the listener. These approaches lie at different ends of a space of interactive sound propagation techniques for modeling sound propagation effects in interactive applications. The first approach emphasizes accuracy by modeling acoustic interactions between all parts of the scene; the second approach emphasizes efficiency by only taking the local environment of the listener into account. These methods have been used to efficiently generate acoustic walkthroughs of architectural models. They have also been integrated into a modern game engine, and can enable realistic, interactive sound propagation on commodity desktop PCs.

Puget Sound Dissolved Oxygen Modeling Study: Development of an Intermediate Scale Water Quality Model

Energy Technology Data Exchange (ETDEWEB)

Khangaonkar, Tarang; Sackmann, Brandon S.; Long, Wen; Mohamedali, Teizeen; Roberts, Mindy

2012-10-01

The Salish Sea, including Puget Sound, is a large estuarine system bounded by over seven thousand miles of complex shorelines, consists of several subbasins and many large inlets with distinct properties of their own. Pacific Ocean water enters Puget Sound through the Strait of Juan de Fuca at depth over the Admiralty Inlet sill. Ocean water mixed with freshwater discharges from runoff, rivers, and wastewater outfalls exits Puget Sound through the brackish surface outflow layer. Nutrient pollution is considered one of the largest threats to Puget Sound. There is considerable interest in understanding the effect of nutrient loads on the water quality and ecological health of Puget Sound in particular and the Salish Sea as a whole. The Washington State Department of Ecology (Ecology) contracted with Pacific Northwest National Laboratory (PNNL) to develop a coupled hydrodynamic and water quality model. The water quality model simulates algae growth, dissolved oxygen, (DO) and nutrient dynamics in Puget Sound to inform potential Puget Sound-wide nutrient management strategies. Specifically, the project is expected to help determine 1) if current and potential future nitrogen loadings from point and non-point sources are significantly impairing water quality at a large scale and 2) what level of nutrient reductions are necessary to reduce or control human impacts to DO levels in the sensitive areas. The project did not include any additional data collection but instead relied on currently available information. This report describes model development effort conducted during the period 2009 to 2012 under a U.S. Environmental Protection Agency (EPA) cooperative agreement with PNNL, Ecology, and the University of Washington awarded under the National Estuary Program

Imagining Sound

DEFF Research Database (Denmark)

Grimshaw, Mark; Garner, Tom Alexander

2014-01-01

We make the case in this essay that sound that is imagined is both a perception and as much a sound as that perceived through external stimulation. To argue this, we look at the evidence from auditory science, neuroscience, and philosophy, briefly present some new conceptual thinking on sound...... that accounts for this view, and then use this to look at what the future might hold in the context of imagining sound and developing technology....

Airframe related aeroacoustics of transport aircraft� -research into prediction and reduction of sound radiation-�

OpenAIRE

Delfs, Jan Werner

2013-01-01

As the sound generation in turbofan engines has decreased the significance of airframe related sound has increased. For example in landing approach the sound associated with the airframe may even dominate the overall sound radiation of an aircraft. The influence of the airframe on aerosound is threefold: i) Airframe components subjected to either their own turbulent boundary layer flow or to installation related turbulent flow act as sources of sound, ii) The aerodynamic influence of the airf...

Retrofitting reciprocating compressors for noise control

International Nuclear Information System (INIS)

Frank, L.; Qualfe, R.

1992-01-01

The Alberta Energy Resources Conservation Board recently enacted their noise control directive ID 88-1. The effects of this regulation on the operation of an oil and gas facility are discussed, and a specific case history is presented to provide a disciplined strategy for noise attenuation retrofits. An investigation was carried out into sound sources at a reciprocating compressor gas plant, revealing several sound sources: engine exhaust stacks, engine exhaust silencer shells, direct-drive fan cooler inlets, direct drive fan cooler outlets, aerial cooler inlets and aerial cooler outlets. Details are presented of the investigative techniques and order-ranking of sources by decibel level. When controlling engine exhaust noise, silencers or mufflers are the preferred treatment. Choice of type (reactive or absorptive) and specification of acoustical performance of a silencer are discussed. The gas plant achieved noise reductions of 6-13 dB, measured at affected residences, through the use of engine exhaust silencers. 4 figs., 2 tabs

Effects of incongruent auditory and visual room-related cues on sound externalization

DEFF Research Database (Denmark)

Carvajal, Juan Camilo Gil; Santurette, Sébastien; Cubick, Jens

Sounds presented via headphones are typically perceived inside the head. However, the illusion of a sound source located out in space away from the listener’s head can be generated with binaural headphone-based auralization systems by convolving anechoic sound signals with a binaural room impulse...... response (BRIR) measured with miniature microphones placed in the listener’s ear canals. Sound externalization of such virtual sounds can be very convincing and robust but there have been reports that the illusion might break down when the listening environment differs from the room in which the BRIRs were...... recorded [1,2,3]. This may be due to incongruent auditory cues between the recording and playback room during sound reproduction [2]. Alternatively, an expectation effect caused by the visual impression of the room may affect the position of the perceived auditory image [3]. Here, we systematically...

Interpretation of time-domain electromagnetic soundings in the Calico Hills area, Nevada Test Site, Nye County, Nevada

International Nuclear Information System (INIS)

Kauahikaua, J.

1981-01-01

A controlled source, time-domain electromagnetic (TDEM) sounding survey was conducted in the Calico Hills area of the Nevada Test Site (NTS). The goal of this survey was the determination of the geoelectric structure as an aid in the evaluation of the site for possible future storage of spent nuclear fuel or high-level nuclear waste. The data were initially interpreted with a simple scheme that produces an apparent resistivity versus depth curve from the vertical magnetic field data. These curves can be qualitatively interpreted much like standard Schlumberger resistivity sounding curves. Final interpretation made use of a layered-earth Marquardt inversion computer program (Kauahikaua, 1980). The results combined with those from a set of Schlumberger soundings in the area show that there is a moderately resistive basement at a depth no greater than 800 meters. The basement resistivity is greater than 100 ohm-meters

Effects of lung elasticity on the sound propagation in the lung

International Nuclear Information System (INIS)

Yoneda, Takahiro; Wada, Shigeo; Nakamura, Masanori; Horii, Noriaki; Mizushima, Koichiro

2011-01-01

Sound propagation in the lung was simulated for gaining insight into its acoustic properties. A thorax model consisting of lung parenchyma, thoracic bones, trachea and other tissues was made from human CT images. Acoustic nature of the lung parenchyma and bones was expressed with the Biot model of poroelastic material, whereas trachea and tissues were modeled with gas and an elastic material. A point sound source of white noises was placed in the first bifurcation of trachea. The sound propagation in the thorax model was simulated in a frequency domain. The results demonstrated the significant attenuation of sound especially in frequencies larger than 1,000 Hz. Simulations with a stiffened lung demonstrated suppression of the sound attenuation for higher frequencies observed in the normal lung. These results indicate that the normal lung has the nature of a low-pass filter, and stiffening helps the sound at higher frequencies to propagate without attenuations. (author)

Root phonotropism: Early signalling events following sound perception in Arabidopsis roots.

Science.gov (United States)

Rodrigo-Moreno, Ana; Bazihizina, Nadia; Azzarello, Elisa; Masi, Elisa; Tran, Daniel; Bouteau, François; Baluska, Frantisek; Mancuso, Stefano

2017-11-01

Sound is a fundamental form of energy and it has been suggested that plants can make use of acoustic cues to obtain information regarding their environments and alter and fine-tune their growth and development. Despite an increasing body of evidence indicating that it can influence plant growth and physiology, many questions concerning the effect of sound waves on plant growth and the underlying signalling mechanisms remains unknown. Here we show that in Arabidopsis thaliana, exposure to sound waves (200Hz) for 2 weeks induced positive phonotropism in roots, which grew towards to sound source. We found that sound waves triggered very quickly (within  minutes) an increase in cytosolic Ca 2+ , possibly mediated by an influx through plasma membrane and a release from internal stock. Sound waves likewise elicited rapid reactive oxygen species (ROS) production and K + efflux. Taken together these results suggest that changes in ion fluxes (Ca 2+ and K + ) and an increase in superoxide production are involved in sound perception in plants, as previously established in animals. Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical Analysis of Indoor Sound Quality Evaluation Using Finite Element Method

Directory of Open Access Journals (Sweden)

Yu-Tuan Chou

2013-01-01

Full Text Available Indoors sound field distribution is important to Room Acoustics, but the field suffers numerous problems, for example, multipath propagation and scattering owing to sound absorption by furniture and other aspects of décor. Generally, an ideal interior space must have a sound field with clear quality. This provides both the speaker and the listener with a pleasant conversational environment. This investigation uses the Finite Element Method to assess the acoustic distribution based on the indoor space and chamber volume. In this situation, a fixed sound source at different frequencies is used to simulate the acoustic characteristics of the indoor space. This method considers the furniture and decoration sound absorbing material and thus different sound absorption coefficients and configurations. The preliminary numerical simulation provides a method that can forecast the distribution of sound in an indoor room in complex situations. Consequently, it is possible to arrange interior furnishings and appliances to optimize acoustic distribution and environmental friendliness. Additionally, the analytical results can also be used to calculate the Reverberation Time and speech intelligibility for specified indoor space.

A double-panel active segmented partition module using decoupled analog feedback controllers: numerical model.

Science.gov (United States)

Sagers, Jason D; Leishman, Timothy W; Blotter, Jonathan D

2009-06-01

Low-frequency sound transmission has long plagued the sound isolation performance of lightweight partitions. Over the past 2 decades, researchers have investigated actively controlled structures to prevent sound transmission from a source space into a receiving space. An approach using active segmented partitions (ASPs) seeks to improve low-frequency sound isolation capabilities. An ASP is a partition which has been mechanically and acoustically segmented into a number of small individually controlled modules. This paper provides a theoretical and numerical development of a single ASP module configuration, wherein each panel of the double-panel structure is independently actuated and controlled by an analog feedback controller. A numerical model is developed to estimate frequency response functions for the purpose of controller design, to understand the effects of acoustic coupling between the panels, to predict the transmission loss of the module in both passive and active states, and to demonstrate that the proposed ASP module will produce bidirectional sound isolation.

Using ILD or ITD Cues for Sound Source Localization and Speech Understanding in a Complex Listening Environment by Listeners with Bilateral and with Hearing-Preservation Cochlear Implants

Science.gov (United States)

Loiselle, Louise H.; Dorman, Michael F.; Yost, William A.; Cook, Sarah J.; Gifford, Rene H.

2016-01-01

Purpose: To assess the role of interaural time differences and interaural level differences in (a) sound-source localization, and (b) speech understanding in a cocktail party listening environment for listeners with bilateral cochlear implants (CIs) and for listeners with hearing-preservation CIs. Methods: Eleven bilateral listeners with MED-EL…

Study of the Acoustic Effects of Hydrokinetic Tidal Turbines in Admiralty Inlet, Puget Sound

Energy Technology Data Exchange (ETDEWEB)

Brian Polagye; Jim Thomson; Chris Bassett; Jason Wood; Dom Tollit; Robert Cavagnaro; Andrea Copping

2012-03-30

Hydrokinetic turbines will be a source of noise in the marine environment - both during operation and during installation/removal. High intensity sound can cause injury or behavioral changes in marine mammals and may also affect fish and invertebrates. These noise effects are, however, highly dependent on the individual marine animals; the intensity, frequency, and duration of the sound; and context in which the sound is received. In other words, production of sound is a necessary, but not sufficient, condition for an environmental impact. At a workshop on the environmental effects of tidal energy development, experts identified sound produced by turbines as an area of potentially significant impact, but also high uncertainty. The overall objectives of this project are to improve our understanding of the potential acoustic effects of tidal turbines by: (1) Characterizing sources of existing underwater noise; (2) Assessing the effectiveness of monitoring technologies to characterize underwater noise and marine mammal responsiveness to noise; (3) Evaluating the sound profile of an operating tidal turbine; and (4) Studying the effect of turbine sound on surrogate species in a laboratory environment. This study focuses on a specific case study for tidal energy development in Admiralty Inlet, Puget Sound, Washington (USA), but the methodologies and results are applicable to other turbine technologies and geographic locations. The project succeeded in achieving the above objectives and, in doing so, substantially contributed to the body of knowledge around the acoustic effects of tidal energy development in several ways: (1) Through collection of data from Admiralty Inlet, established the sources of sound generated by strong currents (mobilizations of sediment and gravel) and determined that low-frequency sound recorded during periods of strong currents is non-propagating pseudo-sound. This helped to advance the debate within the marine and hydrokinetics acoustic

Sound radiation contrast in MR phase images. Method for the representation of elasticity, sound damping, and sound impedance changes

International Nuclear Information System (INIS)

Radicke, Marcus

2009-01-01

The method presented in this thesis combines ultrasound techniques with the magnetic-resonance tomography (MRT). An ultrasonic wave generates in absorbing media a static force in sound-propagation direction. The force leads at sound intensities of some W/cm 2 and a sound frequency in the lower MHz range to a tissue shift in the micrometer range. This tissue shift depends on the sound power, the sound frequency, the sound absorption, and the elastic properties of the tissue. A MRT sequence of the Siemens Healthcare AG was modified so that it measures (indirectly) the tissue shift, codes as grey values, and presents as 2D picture. By means of the grey values the sound-beam slope in the tissue can be visualized, and so additionally sound obstacles (changes of the sound impedance) can be detected. By the MRT images token up spatial changes of the tissue parameters sound absorption and elasticity can be detected. In this thesis measurements are presented, which show the feasibility and future chances of this method especially for the mammary-cancer diagnostics. [de

Open Source Tools for Temporally Controlled Rodent Behavior Suitable for Electrophysiology and Optogenetic Manipulations

Directory of Open Access Journals (Sweden)

Nicola Solari

2018-05-01

Full Text Available Understanding how the brain controls behavior requires observing and manipulating neural activity in awake behaving animals. Neuronal firing is timed at millisecond precision. Therefore, to decipher temporal coding, it is necessary to monitor and control animal behavior at the same level of temporal accuracy. However, it is technically challenging to deliver sensory stimuli and reinforcers as well as to read the behavioral responses they elicit with millisecond precision. Presently available commercial systems often excel in specific aspects of behavior control, but they do not provide a customizable environment allowing flexible experimental design while maintaining high standards for temporal control necessary for interpreting neuronal activity. Moreover, delay measurements of stimulus and reinforcement delivery are largely unavailable. We combined microcontroller-based behavior control with a sound delivery system for playing complex acoustic stimuli, fast solenoid valves for precisely timed reinforcement delivery and a custom-built sound attenuated chamber using high-end industrial insulation materials. Together this setup provides a physical environment to train head-fixed animals, enables calibrated sound stimuli and precisely timed fluid and air puff presentation as reinforcers. We provide latency measurements for stimulus and reinforcement delivery and an algorithm to perform such measurements on other behavior control systems. Combined with electrophysiology and optogenetic manipulations, the millisecond timing accuracy will help interpret temporally precise neural signals and behavioral changes. Additionally, since software and hardware provided here can be readily customized to achieve a large variety of paradigms, these solutions enable an unusually flexible design of rodent behavioral experiments.

Open Source Tools for Temporally Controlled Rodent Behavior Suitable for Electrophysiology and Optogenetic Manipulations.

Science.gov (United States)

Solari, Nicola; Sviatkó, Katalin; Laszlovszky, Tamás; Hegedüs, Panna; Hangya, Balázs

2018-01-01

Understanding how the brain controls behavior requires observing and manipulating neural activity in awake behaving animals. Neuronal firing is timed at millisecond precision. Therefore, to decipher temporal coding, it is necessary to monitor and control animal behavior at the same level of temporal accuracy. However, it is technically challenging to deliver sensory stimuli and reinforcers as well as to read the behavioral responses they elicit with millisecond precision. Presently available commercial systems often excel in specific aspects of behavior control, but they do not provide a customizable environment allowing flexible experimental design while maintaining high standards for temporal control necessary for interpreting neuronal activity. Moreover, delay measurements of stimulus and reinforcement delivery are largely unavailable. We combined microcontroller-based behavior control with a sound delivery system for playing complex acoustic stimuli, fast solenoid valves for precisely timed reinforcement delivery and a custom-built sound attenuated chamber using high-end industrial insulation materials. Together this setup provides a physical environment to train head-fixed animals, enables calibrated sound stimuli and precisely timed fluid and air puff presentation as reinforcers. We provide latency measurements for stimulus and reinforcement delivery and an algorithm to perform such measurements on other behavior control systems. Combined with electrophysiology and optogenetic manipulations, the millisecond timing accuracy will help interpret temporally precise neural signals and behavioral changes. Additionally, since software and hardware provided here can be readily customized to achieve a large variety of paradigms, these solutions enable an unusually flexible design of rodent behavioral experiments.

Acoustic metamaterials capable of both sound insulation and energy harvesting

Science.gov (United States)

Li, Junfei; Zhou, Xiaoming; Huang, Guoliang; Hu, Gengkai

2016-04-01

Membrane-type acoustic metamaterials are well known for low-frequency sound insulation. In this work, by introducing a flexible piezoelectric patch, we propose sound-insulation metamaterials with the ability of energy harvesting from sound waves. The dual functionality of the metamaterial device has been verified by experimental results, which show an over 20 dB sound transmission loss and a maximum energy conversion efficiency up to 15.3% simultaneously. This novel property makes the metamaterial device more suitable for noise control applications.

Acoustic metamaterials capable of both sound insulation and energy harvesting

International Nuclear Information System (INIS)

Li, Junfei; Zhou, Xiaoming; Hu, Gengkai; Huang, Guoliang

2016-01-01

Membrane-type acoustic metamaterials are well known for low-frequency sound insulation. In this work, by introducing a flexible piezoelectric patch, we propose sound-insulation metamaterials with the ability of energy harvesting from sound waves. The dual functionality of the metamaterial device has been verified by experimental results, which show an over 20 dB sound transmission loss and a maximum energy conversion efficiency up to 15.3% simultaneously. This novel property makes the metamaterial device more suitable for noise control applications. (paper)

Sound pressure level tools design used in occupational health by means of Labview software

Directory of Open Access Journals (Sweden)

Farhad Forouharmajd

2015-01-01

Conclusion: LabVIEW programming capabilities in the field of sound can be referred to the measurement of sound, frequency analysis, and sound control that actually the software acts like a sound level meter and sound analyzer. According to the mentioned features, we can use this software to analyze and process sound and vibration as a monitoring system.

A Randomized Controlled Trial on The Beneficial Effects of Training Letter-Speech Sound Integration on Reading Fluency in Children with Dyslexia.

Directory of Open Access Journals (Sweden)

Gorka Fraga González

Full Text Available A recent account of dyslexia assumes that a failure to develop automated letter-speech sound integration might be responsible for the observed lack of reading fluency. This study uses a pre-test-training-post-test design to evaluate the effects of a training program based on letter-speech sound associations with a special focus on gains in reading fluency. A sample of 44 children with dyslexia and 23 typical readers, aged 8 to 9, was recruited. Children with dyslexia were randomly allocated to either the training program group (n = 23 or a waiting-list control group (n = 21. The training intensively focused on letter-speech sound mapping and consisted of 34 individual sessions of 45 minutes over a five month period. The children with dyslexia showed substantial reading gains for the main word reading and spelling measures after training, improving at a faster rate than typical readers and waiting-list controls. The results are interpreted within the conceptual framework assuming a multisensory integration deficit as the most proximal cause of dysfluent reading in dyslexia.ISRCTN register ISRCTN12783279.

Selective attention to sound location or pitch studied with event-related brain potentials and magnetic fields.

Science.gov (United States)

Degerman, Alexander; Rinne, Teemu; Särkkä, Anna-Kaisa; Salmi, Juha; Alho, Kimmo

2008-06-01

Event-related brain potentials (ERPs) and magnetic fields (ERFs) were used to compare brain activity associated with selective attention to sound location or pitch in humans. Sixteen healthy adults participated in the ERP experiment, and 11 adults in the ERF experiment. In different conditions, the participants focused their attention on a designated sound location or pitch, or pictures presented on a screen, in order to detect target sounds or pictures among the attended stimuli. In the Attend Location condition, the location of sounds varied randomly (left or right), while their pitch (high or low) was kept constant. In the Attend Pitch condition, sounds of varying pitch (high or low) were presented at a constant location (left or right). Consistent with previous ERP results, selective attention to either sound feature produced a negative difference (Nd) between ERPs to attended and unattended sounds. In addition, ERPs showed a more posterior scalp distribution for the location-related Nd than for the pitch-related Nd, suggesting partially different generators for these Nds. The ERF source analyses found no source distribution differences between the pitch-related Ndm (the magnetic counterpart of the Nd) and location-related Ndm in the superior temporal cortex (STC), where the main sources of the Ndm effects are thought to be located. Thus, the ERP scalp distribution differences between the location-related and pitch-related Nd effects may have been caused by activity of areas outside the STC, perhaps in the inferior parietal regions.

The NASA Sounding Rocket Program and space sciences

Science.gov (United States)

Gurkin, L. W.

1992-01-01

High altitude suborbital rockets (sounding rockets) have been extensively used for space science research in the post-World War II period; the NASA Sounding Rocket Program has been on-going since the inception of the Agency and supports all space science disciplines. In recent years, sounding rockets have been utilized to provide a low gravity environment for materials processing research, particularly in the commercial sector. Sounding rockets offer unique features as a low gravity flight platform. Quick response and low cost combine to provide more frequent spaceflight opportunities. Suborbital spacecraft design practice has achieved a high level of sophistication which optimizes the limited available flight times. High data-rate telemetry, real-time ground up-link command and down-link video data are routinely used in sounding rocket payloads. Standard, off-the-shelf, active control systems are available which limit payload body rates such that the gravitational environment remains less than 10(-4) g during the control period. Operational launch vehicles are available which can provide up to 7 minutes of experiment time for experiment weights up to 270 kg. Standard payload recovery systems allow soft impact retrieval of payloads. When launched from White Sands Missile Range, New Mexico, payloads can be retrieved and returned to the launch site within hours.

EPICS application source/release control

International Nuclear Information System (INIS)

Zieman, B.; Anderson, J.; Kraimer, M.

1995-01-01

This manual describes a set of Application Source/Release Control tools (appSR) that can be used to develop software for EPICS based control systems. The Application Source/Release Control System (appSR) has been unbundled from base EPICS and is now available as an EPICS extension. Due to this unbundling, two new directories must be added to a user's path (see section ''Environment'' on page 3 for more information) and a new command getapp must be issued after the getrel command to get a specific version of appSR (see section ''Creating The Initial Application System Area'' on page 7 for more information). It is now required that GNU make version 3.71 or later be used for makes instead of SUN make. Users should now type gmake instead of make

Automatic control of a negative ion source

International Nuclear Information System (INIS)

Saadatmand, K.; Sredniawski, J.; Solensten, L.

1989-01-01

A CAMAC based control architecture is devised for a Berkeley-type H - volume ion source. The architecture employs three 80386 PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived. (orig.)

Automatic control of a negative ion source

Science.gov (United States)

Saadatmand, K.; Sredniawski, J.; Solensten, L.

1989-04-01

A CAMAC based control architecture is devised for a Berkeley-type H - volume ion source [1]. The architecture employs three 80386 TM PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived.

Automatic control of a negative ion source

Energy Technology Data Exchange (ETDEWEB)

Saadatmand, K.; Sredniawski, J.; Solensten, L. (Grumman Corp., Long Island, NY (USA))

1989-04-01

A CAMAC based control architecture is devised for a Berkeley-type H/sup -/ volume ion source. The architecture employs three 80386 PCs. One PC is dedicated to control and monitoring of source operation. The other PC functions with digitizers to provide data acquisition of waveforms. The third PC is used for off-line analysis. Initially, operation of the source was put under remote computer control (supervisory). This was followed by development of an automated startup procedure. Finally, a study of the physics of operation is now underway to establish a data base from which automatic beam optimization can be derived. (orig.).

Mass balance constraints on the sources of the petrogenic hydrocarbon background in offshore sediments of Prince William Sound and the Gulf of Alaska

International Nuclear Information System (INIS)

Page, D.S.; Boehm, P.D.; Douglas, G.S.; Brown, J.S.; Bence, A.E.; Burns, W.A.

2000-01-01

A comprehensive sampling program was conducted in 1999 in the offshore sediments of Prince William Sound and the Gulf of Alaska to verify a recent claim that eroding coal beds are the source of petrogenic hydrocarbons background in the area. Samples taken in 1993 and 1994 were reanalyzed to determine concentrations of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. Three Bering River coal samples plus 10 archived source-rock and 3 archived Gulf of Alaska seep and field oil samples from exploration activities in the 1960s and 1970s were also analyzed. The linear combination of the analyte distributions of 18 representative sources that most likely matched the compositions of each sample was derived using the least-squares method. Some of the potential contributing sources which were examined for this study included seep oil, eroding source rocks, eroding coal beds, glacial flour, recent terrestrial sources and human activity. It was determined that the recent claim was incorrect. Eroding Tertiary petroleum source rocks and residues of seep oils are the main sources of hydrocarbon background in the area, rather than area coals or residues from the Exxon Valdez oil spill. 10 refs., 2 tabs., 3 figs

Horizontal sound localization in cochlear implant users with a contralateral hearing aid.

Science.gov (United States)

Veugen, Lidwien C E; Hendrikse, Maartje M E; van Wanrooij, Marc M; Agterberg, Martijn J H; Chalupper, Josef; Mens, Lucas H M; Snik, Ad F M; John van Opstal, A

2016-06-01

Interaural differences in sound arrival time (ITD) and in level (ILD) enable us to localize sounds in the horizontal plane, and can support source segregation and speech understanding in noisy environments. It is uncertain whether these cues are also available to hearing-impaired listeners who are bimodally fitted, i.e. with a cochlear implant (CI) and a contralateral hearing aid (HA). Here, we assessed sound localization behavior of fourteen bimodal listeners, all using the same Phonak HA and an Advanced Bionics CI processor, matched with respect to loudness growth. We aimed to determine the availability and contribution of binaural (ILDs, temporal fine structure and envelope ITDs) and monaural (loudness, spectral) cues to horizontal sound localization in bimodal listeners, by systematically varying the frequency band, level and envelope of the stimuli. The sound bandwidth had a strong effect on the localization bias of bimodal listeners, although localization performance was typically poor for all conditions. Responses could be systematically changed by adjusting the frequency range of the stimulus, or by simply switching the HA and CI on and off. Localization responses were largely biased to one side, typically the CI side for broadband and high-pass filtered sounds, and occasionally to the HA side for low-pass filtered sounds. HA-aided thresholds better than 45 dB HL in the frequency range of the stimulus appeared to be a prerequisite, but not a guarantee, for the ability to indicate sound source direction. We argue that bimodal sound localization is likely based on ILD cues, even at frequencies below 1500 Hz for which the natural ILDs are small. These cues are typically perturbed in bimodal listeners, leading to a biased localization percept of sounds. The high accuracy of some listeners could result from a combination of sufficient spectral overlap and loudness balance in bimodal hearing. Copyright © 2016 Elsevier B.V. All rights reserved.

Using Sound to Modify Fish Behavior at Power-Production and Water-Control Facilities: A Workshop December 12-13, 1995. Phase II: Final Report.

Energy Technology Data Exchange (ETDEWEB)

Carlson, Thomas J. [ed.] [Pacific Northwest National Lab., Richland, WA (United States); Popper, Arthur N. [ed.] [Univ. of Maryland, College Park, MD (United States)

1997-06-01

A workshop on ``Use of Sound for Fish Protection at Power-Production and Water-Control Facilities`` was held in Portland, Oregon on December 12--13, 1995. This workshop convened a 22-member panel of international experts from universities, industry, and government to share knowledge, questions, and ideas about using sound for fish guidance. Discussions involved in a broad range of indigenous migratory and resident fish species and fish-protection issues in river systems, with particular focus on the Columbia River Basin. Because the use of sound behavioral barriers for fish is very much in its infancy, the workshop was designed to address the many questions being asked by fishery managers and researchers about the feasibility and potential benefits of using sound to augment physical barriers for fish protection in the Columbia River system.

Control of sources of ionizing radiation in Lithuania

International Nuclear Information System (INIS)

Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis

1997-01-01

Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented

Development of Prediction Tool for Sound Absorption and Sound Insulation for Sound Proof Properties

OpenAIRE

Yoshio Kurosawa; Takao Yamaguchi

2015-01-01

High frequency automotive interior noise above 500 Hz considerably affects automotive passenger comfort. To reduce this noise, sound insulation material is often laminated on body panels or interior trim panels. For a more effective noise reduction, the sound reduction properties of this laminated structure need to be estimated. We have developed a new calculate tool that can roughly calculate the sound absorption and insulation properties of laminate structure and handy ...

Robust Sounds of Activities of Daily Living Classification in Two-Channel Audio-Based Telemonitoring

Directory of Open Access Journals (Sweden)

David Maunder

2013-01-01

Full Text Available Despite recent advances in the area of home telemonitoring, the challenge of automatically detecting the sound signatures of activities of daily living of an elderly patient using nonintrusive and reliable methods remains. This paper investigates the classification of eight typical sounds of daily life from arbitrarily positioned two-microphone sensors under realistic noisy conditions. In particular, the role of several source separation and sound activity detection methods is considered. Evaluations on a new four-microphone database collected under four realistic noise conditions reveal that effective sound activity detection can produce significant gains in classification accuracy and that further gains can be made using source separation methods based on independent component analysis. Encouragingly, the results show that recognition accuracies in the range 70%–100% can be consistently obtained using different microphone-pair positions, under all but the most severe noise conditions.

Analyses of the mechanisms of amplitude modulation of aero-acoustic wind turbine sound

DEFF Research Database (Denmark)

Fischer, Andreas; Aagaard Madsen, Helge; Kragh, Knud Abildgaard

2014-01-01

This paper explores the source mechanism which cause amplitude modulation of the emitted sound of a wind turbine at large distances from the turbine, named as other amplitude modulation. Measurements of the fluctuating surface pressure on a 2.3MW wind turbine showed a considerable variation over...... give further evidence that transient stall is a main mechanism to cause other amplitude modulation. Wind shear was identified as a critical condition to cause angle of attack variations. Dierent control strategies to mitigate other amplitude modulation were proposed....

Deformation of a sound field caused by a manikin

DEFF Research Database (Denmark)

Weinrich, Søren G.

1981-01-01

around the head at distances of 1 cm to 2 m, measured from the tip of the nose. The signals were pure tones at 1, 2, 4, 6, 8, and 10 kHz. It was found that the presence of the manikin caused changes in the SPL of the sound field of at most ±2.5 dB at a distance of 1 m from the surface of the manikin....... Only over an interval of approximately 20 ° behind the manikin (i.e., opposite the sound source) did the manikin cause much larger changes, up to 9 dB. These changes are caused by destructive interference between sounds coming from opposite sides of the manikin. In front of the manikin, the changes...

Sound Visualisation

OpenAIRE

Dolenc, Peter

2013-01-01

This thesis contains a description of a construction of subwoofer case that has an extra functionality of being able to produce special visual effects and display visualizations that match the currently playing sound. For this reason, multiple lighting elements made out of LED (Light Emitting Diode) diodes were installed onto the subwoofer case. The lighting elements are controlled by dedicated software that was also developed. The software runs on STM32F4-Discovery evaluation board inside a ...

Control of radiation sources in Japan

International Nuclear Information System (INIS)

Maki, S.

2001-01-01

The report refers to the regulations for radioactive material in force in Japan, and to the organizations with responsibilities for regulating radiation sources. An outline of the law regulating the use of radiation sources and radioactive materials is provided, including its scope, types of radiation sources under control, exemptions and the system of notification, authorization and inspection. The experience of Japan with orphan sources is presented in three different cases, and the measures carried out to store the orphan sources in safe conditions. (author)

Making fictions sound real - On film sound, perceptual realism and genre

Directory of Open Access Journals (Sweden)

Birger Langkjær

2010-05-01

Full Text Available This article examines the role that sound plays in making fictions perceptually real to film audiences, whether these fictions are realist or non-realist in content and narrative form. I will argue that some aspects of film sound practices and the kind of experiences they trigger are related to basic rules of human perception, whereas others are more properly explained in relation to how aesthetic devices, including sound, are used to characterise the fiction and thereby make it perceptually real to its audience. Finally, I will argue that not all genres can be defined by a simple taxonomy of sounds. Apart from an account of the kinds of sounds that typically appear in a specific genre, a genre analysis of sound may also benefit from a functionalist approach that focuses on how sounds can make both realist and non-realist aspects of genres sound real to audiences.

Making fictions sound real - On film sound, perceptual realism and genre

Directory of Open Access Journals (Sweden)

Birger Langkjær

2009-09-01

Full Text Available This article examines the role that sound plays in making fictions perceptually real to film audiences, whether these fictions are realist or non-realist in content and narrative form. I will argue that some aspects of film sound practices and the kind of experiences they trigger are related to basic rules of human perception, whereas others are more properly explained in relation to how aesthetic devices, including sound, are used to characterise the fiction and thereby make it perceptually real to its audience. Finally, I will argue that not all genres can be defined by a simple taxonomy of sounds. Apart from an account of the kinds of sounds that typically appear in a specific genre, a genre analysis of sound may also benefit from a functionalist approach that focuses on how sounds can make both realist and non-realist aspects of genres sound real to audiences.

40 CFR 205.54-2 - Sound data acquisition system.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Sound data acquisition system. 205.54-2 Section 205.54-2 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Medium and Heavy Trucks § 205.54-2 Sound...

Sound Localization in Patients With Congenital Unilateral Conductive Hearing Loss With a Transcutaneous Bone Conduction Implant.

Science.gov (United States)

Vyskocil, Erich; Liepins, Rudolfs; Kaider, Alexandra; Blineder, Michaela; Hamzavi, Sasan

2017-03-01

There is no consensus regarding the benefit of implantable hearing aids in congenital unilateral conductive hearing loss (UCHL). This study aimed to measure sound source localization performance in patients with congenital UCHL and contralateral normal hearing who received a new bone conduction implant. Evaluation of within-subject performance differences for sound source localization in a horizontal plane. Tertiary referral center. Five patients with atresia of the external auditory canal and contralateral normal hearing implanted with transcutaneous bone conduction implant at the Medical University of Vienna were tested. Activated/deactivated implant. Sound source localization test; localization performance quantified using the root mean square (RMS) error. Sound source localization ability was highly variable among individual subjects, with RMS errors ranging from 21 to 40 degrees. Horizontal plane localization performance in aided conditions showed statistically significant improvement compared with the unaided conditions, with RMS errors ranging from 17 to 27 degrees. The mean RMS error decreased by a factor of 0.71 (p conduction implant. Some patients with congenital UCHL might be capable of developing improved horizontal plane localization abilities with the binaural cues provided by this device.

Strengthening control over radioactive sources in authorized use and regaining control over orphan sources. National strategies

International Nuclear Information System (INIS)

2004-02-01

The objective of this report is to provide practical guidance to States on the development of a national strategy for improving control over radioactive sources, particularly dangerous sources (Categories 1-3). Part of this process involves the determination of the magnitude of the potential problem with orphan and vulnerable sources and indeed, whether or not a national strategy is needed. The ultimate objective is that States will use this report to develop and then implement a plan of action that will result in all significant sources being managed in a safe and secure manner. This report attempts to provide both the background knowledge and the methodology necessary for an individual or small team of responsible persons to develop a national strategy for improving control over all radioactive sources, but especially orphan and vulnerable sources. The background knowledge given in Chapter 3 is an update of the information on practices that was given in IAEA-TECDOC-804, which focused on spent radioactive sources. After some introductory material, this report provides both the factual information and the general steps needed to develop and implement a national strategy. Part I contains background information for those who are not already familiar with the subject including the need for national strategies, the generic causes of loss of control of sources, with specific examples and the common applications of radioactive sources. Part II details the actual process for the development and implementation of a national strategy, which includes assessing the problem by first gathering specific and national information, determining the nature and magnitude of the problem, developing the national strategy by evaluating, and prioritizing possible solutions, implementing the strategy subsequent to a high level decision; and evaluating the effectiveness of the plan and making changes as a result until the desired objective is achieved. Searches for sources will be part of

Applying the EBU R128 loudness standard in live-streaming sound sculptures

DEFF Research Database (Denmark)

Højlund, Marie Koldkjær; Riis, Morten S.; Rothmann, Daniel

2017-01-01

to preserve a natural sounding dynamic image from the varying sound sources that can be played back under varying conditions, an adaptation of the EBU R128 loudness measurement recommendation, originally developed for levelling non-real-time broadcast material, has been applied. The paper describes the Pure......This paper describes the development of a loudness-based compressor for live audio streams. The need for this device arose while developing the public sound art project The Overheard, which involves mixing together several live audio streams through a web based mixing interface. In order...

Noise Source Visualization Using a Digital Voice Recorder and Low-Cost Sensors.

Science.gov (United States)

Cho, Yong Thung

2018-04-03

Accurate sound visualization of noise sources is required for optimal noise control. Typically, noise measurement systems require microphones, an analog-digital converter, cables, a data acquisition system, etc., which may not be affordable for potential users. Also, many such systems are not highly portable and may not be convenient for travel. Handheld personal electronic devices such as smartphones and digital voice recorders with relatively lower costs and higher performance have become widely available recently. Even though such devices are highly portable, directly implementing them for noise measurement may lead to erroneous results since such equipment was originally designed for voice recording. In this study, external microphones were connected to a digital voice recorder to conduct measurements and the input received was processed for noise visualization. In this way, a low cost, compact sound visualization system was designed and introduced to visualize two actual noise sources for verification with different characteristics: an enclosed loud speaker and a small air compressor. Reasonable accuracy of noise visualization for these two sources was shown over a relatively wide frequency range. This very affordable and compact sound visualization system can be used for many actual noise visualization applications in addition to educational purposes.

Exploring the perceived harshness of cello sounds by morphing and synthesis techniques.

Science.gov (United States)

Rozé, Jocelyn; Aramaki, Mitsuko; Kronland-Martinet, Richard; Ystad, Sølvi

2017-03-01

Cello bowing requires a very fine control of the musicians' gestures to ensure the quality of the perceived sound. When the interaction between the bow hair and the string is optimal, the sound is perceived as broad and round. On the other hand, when the gestural control becomes more approximate, the sound quality deteriorates and often becomes harsh, shrill, and quavering. In this study, such a timbre degradation, often described by French cellists as harshness (décharnement), is investigated from both signal and perceptual perspectives. Harsh sounds were obtained from experienced cellists subjected to a postural constraint. A signal approach based on Gabor masks enabled us to capture the main dissimilarities between round and harsh sounds. Two complementary methods perceptually validated these signal features: First, a predictive regression model of the perceived harshness was built from sound continua obtained by a morphing technique. Next, the signal structures identified by the model were validated within a perceptual timbre space, obtained by multidimensional scaling analysis on pairs of synthesized stimuli controlled in harshness. The results revealed that the perceived harshness was due to a combination between a more chaotic harmonic behavior, a formantic emergence, and a weaker attack slope.

Lung and Heart Sounds Analysis: State-of-the-Art and Future Trends.

Science.gov (United States)

Padilla-Ortiz, Ana L; Ibarra, David

2018-01-01

Lung sounds, which include all sounds that are produced during the mechanism of respiration, may be classified into normal breath sounds and adventitious sounds. Normal breath sounds occur when no respiratory problems exist, whereas adventitious lung sounds (wheeze, rhonchi, crackle, etc.) are usually associated with certain pulmonary pathologies. Heart and lung sounds that are heard using a stethoscope are the result of mechanical interactions that indicate operation of cardiac and respiratory systems, respectively. In this article, we review the research conducted during the last six years on lung and heart sounds, instrumentation and data sources (sensors and databases), technological advances, and perspectives in processing and data analysis. Our review suggests that chronic obstructive pulmonary disease (COPD) and asthma are the most common respiratory diseases reported on in the literature; related diseases that are less analyzed include chronic bronchitis, idiopathic pulmonary fibrosis, congestive heart failure, and parenchymal pathology. Some new findings regarding the methodologies associated with advances in the electronic stethoscope have been presented for the auscultatory heart sound signaling process, including analysis and clarification of resulting sounds to create a diagnosis based on a quantifiable medical assessment. The availability of automatic interpretation of high precision of heart and lung sounds opens interesting possibilities for cardiovascular diagnosis as well as potential for intelligent diagnosis of heart and lung diseases.

Development of the Database for Environmental Sound Research and Application (DESRA: Design, Functionality, and Retrieval Considerations

Directory of Open Access Journals (Sweden)

Brian Gygi

2010-01-01

Full Text Available Theoretical and applied environmental sounds research is gaining prominence but progress has been hampered by the lack of a comprehensive, high quality, accessible database of environmental sounds. An ongoing project to develop such a resource is described, which is based upon experimental evidence as to the way we listen to sounds in the world. The database will include a large number of sounds produced by different sound sources, with a thorough background for each sound file, including experimentally obtained perceptual data. In this way DESRA can contain a wide variety of acoustic, contextual, semantic, and behavioral information related to an individual sound. It will be accessible on the Internet and will be useful to researchers, engineers, sound designers, and musicians.

Sound Absorbers

Science.gov (United States)

Fuchs, H. V.; Möser, M.

Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

Listening panel agreement and characteristics of lung sounds digitally recorded from children aged 1–59 months enrolled in the Pneumonia Etiology Research for Child Health (PERCH) case–control study

Science.gov (United States)

Park, Daniel E; Watson, Nora L; Buck, W Chris; Bunthi, Charatdao; Devendra, Akash; Ebruke, Bernard E; Elhilali, Mounya; Emmanouilidou, Dimitra; Garcia-Prats, Anthony J; Githinji, Leah; Hossain, Lokman; Madhi, Shabir A; Moore, David P; Mulindwa, Justin; Olson, Dan; Awori, Juliet O; Vandepitte, Warunee P; Verwey, Charl; West, James E; Knoll, Maria D; O'Brien, Katherine L; Feikin, Daniel R; Hammit, Laura L

2017-01-01

Introduction Paediatric lung sound recordings can be systematically assessed, but methodological feasibility and validity is unknown, especially from developing countries. We examined the performance of acoustically interpreting recorded paediatric lung sounds and compared sound characteristics between cases and controls. Methods Pneumonia Etiology Research for Child Health staff in six African and Asian sites recorded lung sounds with a digital stethoscope in cases and controls. Cases aged 1–59 months had WHO severe or very severe pneumonia; age-matched community controls did not. A listening panel assigned examination results of normal, crackle, wheeze, crackle and wheeze or uninterpretable, with adjudication of discordant interpretations. Classifications were recategorised into any crackle, any wheeze or abnormal (any crackle or wheeze) and primary listener agreement (first two listeners) was analysed among interpretable examinations using the prevalence-adjusted, bias-adjusted kappa (PABAK). We examined predictors of disagreement with logistic regression and compared case and control lung sounds with descriptive statistics. Results Primary listeners considered 89.5% of 792 case and 92.4% of 301 control recordings interpretable. Among interpretable recordings, listeners agreed on the presence or absence of any abnormality in 74.9% (PABAK 0.50) of cases and 69.8% (PABAK 0.40) of controls, presence/absence of crackles in 70.6% (PABAK 0.41) of cases and 82.4% (PABAK 0.65) of controls and presence/absence of wheeze in 72.6% (PABAK 0.45) of cases and 73.8% (PABAK 0.48) of controls. Controls, tachypnoea, >3 uninterpretable chest positions, crying, upper airway noises and study site predicted listener disagreement. Among all interpretable examinations, 38.0% of cases and 84.9% of controls were normal (p<0.0001); wheezing was the most common sound (49.9%) in cases. Conclusions Listening panel and case–control data suggests our methodology is feasible, likely valid

Perception of environmental sounds by experienced cochlear implant patients

Science.gov (United States)

Shafiro, Valeriy; Gygi, Brian; Cheng, Min-Yu; Vachhani, Jay; Mulvey, Megan

2011-01-01

Objectives Environmental sound perception serves an important ecological function by providing listeners with information about objects and events in their immediate environment. Environmental sounds such as car horns, baby cries or chirping birds can alert listeners to imminent dangers as well as contribute to one's sense of awareness and well being. Perception of environmental sounds as acoustically and semantically complex stimuli, may also involve some factors common to the processing of speech. However, very limited research has investigated the abilities of cochlear implant (CI) patients to identify common environmental sounds, despite patients' general enthusiasm about them. This project (1) investigated the ability of patients with modern-day CIs to perceive environmental sounds, (2) explored associations among speech, environmental sounds and basic auditory abilities, and (3) examined acoustic factors that might be involved in environmental sound perception. Design Seventeen experienced postlingually-deafened CI patients participated in the study. Environmental sound perception was assessed with a large-item test composed of 40 sound sources, each represented by four different tokens. The relationship between speech and environmental sound perception, and the role of working memory and some basic auditory abilities were examined based on patient performance on a battery of speech tests (HINT, CNC, and individual consonant and vowel tests), tests of basic auditory abilities (audiometric thresholds, gap detection, temporal pattern and temporal order for tones tests) and a backward digit recall test. Results The results indicated substantially reduced ability to identify common environmental sounds in CI patients (45.3%). Except for vowels, all speech test scores significantly correlated with the environmental sound test scores: r = 0.73 for HINT in quiet, r = 0.69 for HINT in noise, r = 0.70 for CNC, r = 0.64 for consonants and r = 0.48 for vowels. HINT and

Acquired Apraxia of Speech: The Effects of Repeated Practice and Rate/Rhythm Control Treatments on Sound Production Accuracy

Science.gov (United States)

Wambaugh, Julie L.; Nessler, Christina; Cameron, Rosalea; Mauszycki, Shannon C.

2012-01-01

Purpose: This investigation was designed to elucidate the effects of repeated practice treatment on sound production accuracy in individuals with apraxia of speech (AOS) and aphasia. A secondary purpose was to determine if the addition of rate/rhythm control to treatment provided further benefits beyond those achieved with repeated practice.…

Inadequate control of world's radioactive sources

International Nuclear Information System (INIS)

2002-01-01

The radioactive materials needed to build a 'dirty bomb' can be found in almost any country in the world, and more than 100 countries may have inadequate control and monitoring programs necessary to prevent or even detect the theft of these materials. The IAEA points out that while radioactive sources number in the millions, only a small percentage have enough strength to cause serious radiological harm. It is these powerful sources that need to be focused on as a priority. In a significant recent development, the IAEA, working in collaboration with the United States Department of Energy (DOE) and the Russian Federation's Ministry for Atomic Energy (MINATOM), have established a tripartite working group on 'Securing and Managing Radioactive Sources'. Through its program to help countries improve their national infrastructures for radiation safety and security, the IAEA has found that more than 100 countries may have no minimum infrastructure in place to properly control radiation sources. However, many IAEA Member States - in Africa, Asia, Latin America, and Europe - are making progress through an IAEA project to strengthen their capabilities to control and regulate radioactive sources. The IAEA is also concerned about the over 50 countries that are not IAEA Member States (there are 134), as they do not benefit from IAEA assistance and are likely to have no regulatory infrastructure. The IAEA has been active in lending its expertise to search out and secure orphaned sources in several countries. More than 70 States have joined with the IAEA to collect and share information on trafficking incidents and other unauthorized movements of radioactive sources and other radioactive materials. The IAEA and its Member States are working hard to raise levels of radiation safety and security, especially focusing on countries known to have urgent needs. The IAEA has taken the leading role in the United Nations system in establishing standards of safety, the most significant of

Recent Advances in the Sound Insulation Properties of Bio-based Materials

Directory of Open Access Journals (Sweden)

Xiaodong Zhu

2013-12-01

Full Text Available Many bio-based materials, which have lower environmental impact than traditional synthetic materials, show good sound absorbing and sound insulation performances. This review highlights progress in sound transmission properties of bio-based materials and provides a comprehensive account of various multiporous bio-based materials and multilayered structures used in sound absorption and insulation products. Furthermore, principal models of sound transmission are discussed in order to aid in an understanding of sound transmission properties of bio-based materials. In addition, the review presents discussions on the composite structure optimization and future research in using co-extruded wood plastic composite for sound insulation control. This review contributes to the body of knowledge on the sound transmission properties of bio-based materials, provides a better understanding of the models of some multiporous bio-based materials and multilayered structures, and contributes to the wider adoption of bio-based materials as sound absorbers.

An objective measure for the sensitivity of room impulse response and its link to a diffuse sound field

DEFF Research Database (Denmark)

Prislan, Rok; Brunskog, Jonas; Jacobsen, Finn

2014-01-01

This study is relevant to acoustic measurements in reverberation rooms such as measurements of sound transmission, sound absorption, and sound power levels of noise sources. The study presents a quantitative measure for the diffuseness in a room, which is first introduced theoretically and sub...

Accurate three dimensional characterization of ultrasonic sound fields (by computer controlled rotational scanning)

International Nuclear Information System (INIS)

Gundtoft, H.E.; Nielsen, T.

1981-07-01

A rotational scanning system has recently been developed at Risoe National Laboratory. It allows sound fields from ultrasonic transducers to be examined in 3 dimensions. Using different calculation and plotting programs, any section in the sound field can be plotted. Results from examination of transducers for automatic inspection are presented. (author)

Investigation of hydraulic transmission noise sources

Science.gov (United States)

Klop, Richard J.

Advanced hydrostatic transmissions and hydraulic hybrids show potential in new market segments such as commercial vehicles and passenger cars. Such new applications regard low noise generation as a high priority, thus, demanding new quiet hydrostatic transmission designs. In this thesis, the aim is to investigate noise sources of hydrostatic transmissions to discover strategies for designing compact and quiet solutions. A model has been developed to capture the interaction of a pump and motor working in a hydrostatic transmission and to predict overall noise sources. This model allows a designer to compare noise sources for various configurations and to design compact and inherently quiet solutions. The model describes dynamics of the system by coupling lumped parameter pump and motor models with a one-dimensional unsteady compressible transmission line model. The model has been verified with dynamic pressure measurements in the line over a wide operating range for several system structures. Simulation studies were performed illustrating sensitivities of several design variables and the potential of the model to design transmissions with minimal noise sources. A semi-anechoic chamber has been designed and constructed suitable for sound intensity measurements that can be used to derive sound power. Measurements proved the potential to reduce audible noise by predicting and reducing both noise sources. Sound power measurements were conducted on a series hybrid transmission test bench to validate the model and compare predicted noise sources with sound power.

Evaluation of the Performance of Feedforward and Recurrent Neural Networks in Active Cancellation of Sound Noise

OpenAIRE

Mehrshad Salmasi; Homayoun Mahdavi-Nasab

2012-01-01

Active noise control is based on the destructive interference between the primary noise and generated noise from the secondary source. An antinoise of equal amplitude and opposite phase is generated and combined with the primary noise. In this paper, performance of the neural networks is evaluated in active cancellation of sound noise. For this reason, feedforward and recurrent neural networks are designed and trained. After training, performance of the feedforwrad and recurrent networks in n...

2nd Symposium on Fluid-Structure-Sound Interactions and Control

CERN Document Server

Liu, Yang; Huang, Lixi; Hodges, Dewey

2014-01-01

With rapid economic and industrial development in China, India and elsewhere, fluid-related structural vibration and noise problems are widely encountered in many fields, just as they are in the more developed parts of the world, causing increasingly grievous concerns. Turbulence clearly has a significant impact on many such problems. On the other hand, new opportunities are emerging with the advent of various new technologies, such as signal processing, flow visualization and diagnostics, new functional materials, sensors and actuators, etc. These have revitalized interdisciplinary research activities, and it is in this context that the 2nd symposium on fluid-structure-sound interactions and control (FSSIC) was organized. Held in Hong Kong (May 20-21, 2013) and Macau (May 22-23, 2013), the meeting brought together scientists and engineers working in all related branches from both East and West and provided them with a forum to exchange and share the latest progress, ideas and advances and to chart the fronti...

A framework for automatic heart sound analysis without segmentation

Directory of Open Access Journals (Sweden)

Tungpimolrut Kanokvate

2011-02-01

Full Text Available Abstract Background A new framework for heart sound analysis is proposed. One of the most difficult processes in heart sound analysis is segmentation, due to interference form murmurs. Method Equal number of cardiac cycles were extracted from heart sounds with different heart rates using information from envelopes of autocorrelation functions without the need to label individual fundamental heart sounds (FHS. The complete method consists of envelope detection, calculation of cardiac cycle lengths using auto-correlation of envelope signals, features extraction using discrete wavelet transform, principal component analysis, and classification using neural network bagging predictors. Result The proposed method was tested on a set of heart sounds obtained from several on-line databases and recorded with an electronic stethoscope. Geometric mean was used as performance index. Average classification performance using ten-fold cross-validation was 0.92 for noise free case, 0.90 under white noise with 10 dB signal-to-noise ratio (SNR, and 0.90 under impulse noise up to 0.3 s duration. Conclusion The proposed method showed promising results and high noise robustness to a wide range of heart sounds. However, more tests are needed to address any bias that may have been introduced by different sources of heart sounds in the current training set, and to concretely validate the method. Further work include building a new training set recorded from actual patients, then further evaluate the method based on this new training set.

Sound beam manipulation based on temperature gradients

Energy Technology Data Exchange (ETDEWEB)

Qian, Feng [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); School of Physics & Electronic Engineering, Changshu Institute of Technology, Changshu 215500 (China); Quan, Li; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

2015-10-28

Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

Making Sound Connections

Science.gov (United States)

Deal, Walter F., III

2007-01-01

Sound provides and offers amazing insights into the world. Sound waves may be defined as mechanical energy that moves through air or other medium as a longitudinal wave and consists of pressure fluctuations. Humans and animals alike use sound as a means of communication and a tool for survival. Mammals, such as bats, use ultrasonic sound waves to…

Behavioral response of manatees to variations in environmental sound levels

Science.gov (United States)

Miksis-Olds, Jennifer L.; Wagner, Tyler

2011-01-01

Florida manatees (Trichechus manatus latirostris) inhabit coastal regions because they feed on the aquatic vegetation that grows in shallow waters, which are the same areas where human activities are greatest. Noise produced from anthropogenic and natural sources has the potential to affect these animals by eliciting responses ranging from mild behavioral changes to extreme aversion. Sound levels were calculated from recordings made throughout behavioral observation periods. An information theoretic approach was used to investigate the relationship between behavior patterns and sound level. Results indicated that elevated sound levels affect manatee activity and are a function of behavioral state. The proportion of time manatees spent feeding and milling changed in response to sound level. When ambient sound levels were highest, more time was spent in the directed, goal-oriented behavior of feeding, whereas less time was spent engaged in undirected behavior such as milling. This work illustrates how shifts in activity of individual manatees may be useful parameters for identifying impacts of noise on manatees and might inform population level effects.

Control of sources of ionizing radiation in Lithuania

Energy Technology Data Exchange (ETDEWEB)

Mastauskas, Albinas; Ziliukas, Julius; Morkunas, Gendrutis [Radiation Protection Centre, Vilnius (Lithuania)

1997-12-31

Aspects connected with regulatory control of radioactive sources in Lithuania, such as keeping of the computer-based registry, investigation of arrested illegal radioactive material, decision making, control of users of radioactive sources are discussed. Most of the sources of ionizing radiation are smoke detectors and x-ray equipment. Potentially most dangerous sources (both sealed and unsealed) of therapy and industry are also presented 2 refs., 2 tabs.; e-mail: rsc at post.omnitel.net

Neutron generator tube ion source control apparatus

International Nuclear Information System (INIS)

Bridges, J.R.

1982-01-01

A pulsed neutron well logging system includes a neutron generator tube of the deuterium-tritium accelerator type and an ion source control apparatus providing extremely sharply time-defined neutron pulses. A low voltage control pulse supplied to an input by timing circuits turns a power FET on via a buffer-driver whereby a 2000 volt pulse is produced in the secondary of a pulse transformer and applied to the ion source of the tube. A rapid fall in this ion source control pulse is ensured by a quenching circuit wherein a one-shot responds to the falling edge of the control pulse and produces a 3 microsecond delay to compensate for the propagation delay. A second one-shot is triggered by the falling edge of the output of the first one-shot and gives an 8 microsecond pulse to turn on the power FET which, via an isolation transformer turns on a series-connected transistor to ground the secondary of the pulse transformer and the ion source. (author)

Theoretical analysis of sound transmission loss through graphene sheets

International Nuclear Information System (INIS)

Natsuki, Toshiaki; Ni, Qing-Qing

2014-01-01

We examine the potential of using graphene sheets (GSs) as sound insulating materials that can be used for nano-devices because of their small size, super electronic, and mechanical properties. In this study, a theoretical analysis is proposed to predict the sound transmission loss through multi-layered GSs, which are formed by stacks of GS and bound together by van der Waals (vdW) forces between individual layers. The result shows that the resonant frequencies of the sound transmission loss occur in the multi-layered GSs and the values are very high. Based on the present analytical solution, we predict the acoustic insulation property for various layers of sheets under both normal incident wave and acoustic field of random incidence source. The scheme could be useful in vibration absorption application of nano devices and materials

Theoretical analysis of sound transmission loss through graphene sheets

Energy Technology Data Exchange (ETDEWEB)

Natsuki, Toshiaki, E-mail: natsuki@shinshu-u.ac.jp [Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567 (Japan); Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Ni, Qing-Qing [Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda 386-8567 (Japan)

2014-11-17

We examine the potential of using graphene sheets (GSs) as sound insulating materials that can be used for nano-devices because of their small size, super electronic, and mechanical properties. In this study, a theoretical analysis is proposed to predict the sound transmission loss through multi-layered GSs, which are formed by stacks of GS and bound together by van der Waals (vdW) forces between individual layers. The result shows that the resonant frequencies of the sound transmission loss occur in the multi-layered GSs and the values are very high. Based on the present analytical solution, we predict the acoustic insulation property for various layers of sheets under both normal incident wave and acoustic field of random incidence source. The scheme could be useful in vibration absorption application of nano devices and materials.

Jump in the amplitude of a sound wave associated with contraction of a nitrogen discharge

International Nuclear Information System (INIS)

Galechyan, G.A.; Mkrtchyan, A.R.; Tavakalyan, L.B.

1993-01-01

The use of a sound wave created by an external source and directed along the positive column of a nitrogen discharge in order to make the discharge pass to the contracted state is studied experimentally. A phenomenon involving a jump in the sound wave amplitude, caused by the discharge contraction, is observed and studied. It is established that the amplitude of the sound wave as a function of the discharge current near the jump exhibits hysteresis. It is shown that in the field of a high-intensity sound wave causing the discharge to expand eliminates the jump in the sound amplitude. The dependence of the growth time of the sound amplitude caused by the jump in this quantity on the sound wave intensity is determined. 24 refs., 4 figs., 1 tab

Physiological correlates of sound localization in a parasitoid fly, Ormia ochracea

Science.gov (United States)

Oshinsky, Michael Lee

A major focus of research in the nervous system is the investigation of neural circuits. The question of how neurons connect to form functional units has driven modern neuroscience research from its inception. From the beginning, the neural circuits of the auditory system and specifically sound localization were used as a model system for investigating neural connectivity and computation. Sound localization lends itself to this task because there is no mapping of spatial information on a receptor sheet as in vision. With only one eye, an animal would still have positional information for objects. Since the receptor sheet in the ear is frequency oriented and not spatially oriented, positional information for a sound source does not exist with only one ear. The nervous system computes the location of a sound source based on differences in the physiology of the two ears. In this study, I investigated the neural circuits for sound localization in a fly, Ormia ochracea (Diptera, Tachinidae, Ormiini), which is a parasitoid of crickets. This fly possess a unique mechanically coupled hearing organ. The two ears are contained in one air sac and a cuticular bridge, that has a flexible spring-like structure at its center, connects them. This mechanical coupling preprocesses the sound before it is detected by the nervous system and provides the fly with directional information. The subject of this study is the neural coding of the location of sound stimuli by a mechanically coupled auditory system. In chapter 1, I present the natural history of an acoustic parasitoid and I review the peripheral processing of sound by the Ormian ear. In chapter 2, I describe the anatomy and physiology of the auditory afferents. I present this physiology in the context of sound localization. In chapter 3, I describe the directional dependent physiology for the thoracic local and ascending acoustic interneurons. In chapter 4, I quantify the threshold and I detail the kinematics of the phonotactic

Perception of Animacy from the Motion of a Single Sound Object.

Science.gov (United States)

Nielsen, Rasmus Høll; Vuust, Peter; Wallentin, Mikkel

2015-02-01

Research in the visual modality has shown that the presence of certain dynamics in the motion of an object has a strong effect on whether or not the entity is perceived as animate. Cues for animacy are, among others, self-propelled motion and direction changes that are seemingly not caused by entities external to, or in direct contact with, the moving object. The present study aimed to extend this research into the auditory domain by determining if similar dynamics could influence the perceived animacy of a sound source. In two experiments, participants were presented with single, synthetically generated 'mosquito' sounds moving along trajectories in space, and asked to rate how certain they were that each sound-emitting entity was alive. At a random point on a linear motion trajectory, the sound source would deviate from its initial path and speed. Results confirm findings from the visual domain that a change in the velocity of motion is positively correlated with perceived animacy, and changes in direction were found to influence animacy judgment as well. This suggests that an ability to facilitate and sustain self-movement is perceived as a living quality not only in the visual domain, but in the auditory domain as well. © 2015 SAGE Publications.

Optical Reading and Playing of Sound Signals from Vinyl Records

OpenAIRE

Hensman, Arnold; Casey, Kevin

2007-01-01

While advanced digital music systems such as compact disk players and MP3 have become the standard in sound reproduction technology, critics claim that conversion to digital often results in a loss of sound quality and richness. For this reason, vinyl records remain the medium of choice for many audiophiles involved in specialist areas. The waveform cut into a vinyl record is an exact replica of the analogue version from the original source. However, while some perceive this media as reproduc...

Characteristics and prediction of sound level in extra-large spaces

OpenAIRE

Wang, C.; Ma, H.; Wu, Y.; Kang, J.

2018-01-01

This paper aims to examine sound fields in extra-large spaces, which are defined in this paper as spaces used by people, with a volume approximately larger than 125,000m 3 and absorption coefficient less than 0.7. In such spaces inhomogeneous reverberant energy caused by uneven early reflections with increasing volume has a significant effect on sound fields. Measurements were conducted in four spaces to examine the attenuation of the total and reverberant energy with increasing source-receiv...

Comparing Feedback Types in Multimedia Learning of Speech by Young Children With Common Speech Sound Disorders: Research Protocol for a Pretest Posttest Independent Measures Control Trial.

Science.gov (United States)

Doubé, Wendy; Carding, Paul; Flanagan, Kieran; Kaufman, Jordy; Armitage, Hannah

2018-01-01

Children with speech sound disorders benefit from feedback about the accuracy of sounds they make. Home practice can reinforce feedback received from speech pathologists. Games in mobile device applications could encourage home practice, but those currently available are of limited value because they are unlikely to elaborate "Correct"/"Incorrect" feedback with information that can assist in improving the accuracy of the sound. This protocol proposes a "Wizard of Oz" experiment that aims to provide evidence for the provision of effective multimedia feedback for speech sound development. Children with two common speech sound disorders will play a game on a mobile device and make speech sounds when prompted by the game. A human "Wizard" will provide feedback on the accuracy of the sound but the children will perceive the feedback as coming from the game. Groups of 30 young children will be randomly allocated to one of five conditions: four types of feedback and a control which does not play the game. The results of this experiment will inform not only speech sound therapy, but also other types of language learning, both in general, and in multimedia applications. This experiment is a cost-effective precursor to the development of a mobile application that employs pedagogically and clinically sound processes for speech development in young children.

Time-lapse controlled-source electromagnetics using interferometry

NARCIS (Netherlands)

Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

In time-lapse controlled-source electromagnetics, it is crucial that the source and the receivers are positioned at exactly the same location at all times of measurement. We use interferometry by multidimensional deconvolution (MDD) to overcome problems in repeatability of the source location.

Embedded audio without beeps: synthesis and sound effects from cheap to steep

DEFF Research Database (Denmark)

Møbius, Nikolaj; Overholt, Dan

2015-01-01

, and wireless devices for the control of sound or music generated remotely. For example, studio creations can synthesize sound directly with an Arduino or a more powerful "Create USB Interface" board via Direct Digital Synthesis. Alternatively, they can control a program such as Pure Data (or other common...

Anti-sound and Acoustical Cloaks

Directory of Open Access Journals (Sweden)

Veturia CHIROIU

2016-12-01

Full Text Available The principles by which the acoustics can be mimicked in order to reduce or cancel the vibrational field are based on anti-sound concept which can be materialized by acoustic cloaks. Geometric transformations open an elegant way towards the unconstrained control of sound through acoustic metamaterials. Acoustic cloaks can be achieved through geometric transformations which bring exotic metamaterial properties into the acoustic equations. Our paper brings new ideas concerning the technological keys for manufacturing of novel metamaterials based on the spatial compression of Cantor structures, and the architecture of 3D acoustic cloaks in a given frequency band, with application to architectural acoustics.

Sound Search Engine Concept

DEFF Research Database (Denmark)

2006-01-01

Sound search is provided by the major search engines, however, indexing is text based, not sound based. We will establish a dedicated sound search services with based on sound feature indexing. The current demo shows the concept of the sound search engine. The first engine will be realased June...

Method for measuring violin sound radiation based on bowed glissandi and its application to sound synthesis.

Science.gov (United States)

Perez Carrillo, Alfonso; Bonada, Jordi; Patynen, Jukka; Valimaki, Vesa

2011-08-01

This work presents a method for measuring and computing violin-body directional frequency responses, which are used for violin sound synthesis. The approach is based on a frame-weighted deconvolution of excitation and response signals. The excitation, consisting of bowed glissandi, is measured with piezoelectric transducers built into the bridge. Radiation responses are recorded in an anechoic chamber with multiple microphones placed at different angles around the violin. The proposed deconvolution algorithm computes impulse responses that, when convolved with any source signal (captured with the same transducer), produce a highly realistic violin sound very similar to that of a microphone recording. The use of motion sensors allows for tracking violin movements. Combining this information with the directional responses and using a dynamic convolution algorithm, helps to improve the listening experience by incorporating the violinist motion effect in stereo.

Direct Measurement of the Speed of Sound Using a Microphone and a Speaker

Science.gov (United States)

Gómez-Tejedor, José A.; Castro-Palacio, Juan C.; Monsoriu, Juan A.

2014-01-01

We present a simple and accurate experiment to obtain the speed of sound in air using a conventional speaker and a microphone connected to a computer. A free open source digital audio editor and recording computer software application allows determination of the time-of-flight of the wave for different distances, from which the speed of sound is…

A taste for words and sounds: a case of lexical-gustatory and sound-gustatory synesthesia

Directory of Open Access Journals (Sweden)

Olympia eColizoli

2013-10-01

Full Text Available Gustatory forms of synesthesia involve the automatic and consistent experience of tastes that are triggered by non-taste related inducers. We present a case of lexical-gustatory and sound-gustatory synesthesia within one individual, SC. Most words and a subset of nonlinguistic sounds induce the experience of taste, smell and physical sensations for SC. SC’s lexical-gustatory associations were significantly more consistent than those of a group of controls. We tested for effects of presentation modality (visual vs. auditory, taste-related congruency, and synesthetic inducer-concurrent direction using a priming task. SC’s performance did not differ significantly from a trained control group. We used functional magnetic resonance imaging to investigate the neural correlates of SC’s synesthetic experiences by comparing her brain activation to the literature on brain networks related to language, music and sound processing, in addition to synesthesia. Words that induced a strong taste were contrasted to words that induced weak-to-no tastes (tasty vs. tasteless words. Brain activation was also measured during passive listening to music and environmental sounds. Brain activation patterns showed evidence that two regions are implicated in SC’s synesthetic experience of taste and smell: the left anterior insula and left superior parietal lobe. Anterior insula activation may reflect the synesthetic taste experience. The superior parietal lobe is proposed to be involved in binding sensory information across sub-types of synesthetes. We conclude that SC’s synesthesia is genuine and reflected in her brain activation. The type of inducer (visual-lexical, auditory-lexical, and non-lexical auditory stimuli could be differentiated based on patterns of brain activity.

Coupled simulation of meteorological parameters and sound intensity in a narrow valley

Energy Technology Data Exchange (ETDEWEB)

Heimann, D. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Gross, G. [Hannover Univ. (Germany). Inst. fuer Meteorologie und Klimatologie

1997-07-01

A meteorological mesoscale model is used to simulate the inhomogeneous distribution of temperature and the appertaining development of thermal wind systems in a narrow two-dimensional valley during the course of a cloud-free day. A simple sound particle model takes up the simulated meteorological fields and calculates the propagation of noise which originates from a line source at one of the slopes of this valley. The coupled modeling system ensures consistency of topography, meteorological parameters and the sound field. The temporal behaviour of the sound intensity level across the valley is examined. It is only governed by the time-dependent meteorology. The results show remarkable variations of the sound intensity during the course of a day depending on the location in the valley. (orig.) 23 refs.

The sound manifesto

Science.gov (United States)

O'Donnell, Michael J.; Bisnovatyi, Ilia

2000-11-01

Computing practice today depends on visual output to drive almost all user interaction. Other senses, such as audition, may be totally neglected, or used tangentially, or used in highly restricted specialized ways. We have excellent audio rendering through D-A conversion, but we lack rich general facilities for modeling and manipulating sound comparable in quality and flexibility to graphics. We need coordinated research in several disciplines to improve the use of sound as an interactive information channel. Incremental and separate improvements in synthesis, analysis, speech processing, audiology, acoustics, music, etc. will not alone produce the radical progress that we seek in sonic practice. We also need to create a new central topic of study in digital audio research. The new topic will assimilate the contributions of different disciplines on a common foundation. The key central concept that we lack is sound as a general-purpose information channel. We must investigate the structure of this information channel, which is driven by the cooperative development of auditory perception and physical sound production. Particular audible encodings, such as speech and music, illuminate sonic information by example, but they are no more sufficient for a characterization than typography is sufficient for characterization of visual information. To develop this new conceptual topic of sonic information structure, we need to integrate insights from a number of different disciplines that deal with sound. In particular, we need to coordinate central and foundational studies of the representational models of sound with specific applications that illuminate the good and bad qualities of these models. Each natural or artificial process that generates informative sound, and each perceptual mechanism that derives information from sound, will teach us something about the right structure to attribute to the sound itself. The new Sound topic will combine the work of computer

Experimental analysis of considering the sound pressure distribution pattern at the ear canal entrance as an unrevealed head-related localization clue

Institute of Scientific and Technical Information of China (English)

TONG Xin; QI Na; MENG Zihou

2018-01-01

By analyzing the differences between binaural recording and real listening,it was deduced that there were some unrevealed auditory localization clues,and the sound pressure distribution pattern at the entrance of ear canal was probably a clue.It was proved through the listening test that the unrevealed auditory localization clues really exist with the reduction to absurdity.And the effective frequency bands of the unrevealed localization clues were induced and summed.The result of finite element based simulations showed that the pressure distribution at the entrance of ear canal was non-uniform,and the pattern was related to the direction of sound source.And it was proved that the sound pressure distribution pattern at the entrance of the ear canal carried the sound source direction information and could be used as an unrevealed localization cluc.The frequency bands in which the sound pressure distribution patterns had significant differences between front and back sound source directions were roughly matched with the effective frequency bands of unrevealed localization clues obtained from the listening tests.To some extent,it supports the hypothesis that the sound pressure distribution pattern could be a kind of unrevealed auditory localization clues.

Speed of sound in biodiesel produced by low power ultrasound

Science.gov (United States)

Oliveira, P. A.; Silva, R. M. B.; Morais, G. C.; Alvarenga, A. V.; Costa-Felix, R. P. B.

2018-03-01

The quality control of the biodiesel produced is an important issue to be addressed for every manufacturer or retailer. The speed of sound is a property that has an influence on the quality of the produced fuel. This work presents the evaluation about the speed of sound in biodiesel produced with the aid of low power ultrasound in the frequencies of 1 MHz and 3 MHz. The speed of sound was measured by pulse-echo technique. The ultrasonic frequency used during reaction affects the speed of sound in biodiesel. The larger expanded uncertainty for adjusted curve was 4.9 m.s-1.

Unsound Sound

DEFF Research Database (Denmark)

Knakkergaard, Martin

2016-01-01

This article discusses the change in premise that digitally produced sound brings about and how digital technologies more generally have changed our relationship to the musical artifact, not simply in degree but in kind. It demonstrates how our acoustical conceptions are thoroughly challenged...... by the digital production of sound and, by questioning the ontological basis for digital sound, turns our understanding of the core term substance upside down....

Urban stormwater source control policies: why and how?

Directory of Open Access Journals (Sweden)

G. Petrucci

2014-09-01

Full Text Available Stormwater source control is becoming a common strategy for urban stormwater management in many countries. It relies on regulations or other policy instruments compelling or inciting implementation, for each new urban development, of small-scale facilities to locally store and manage stormwater. Local authorities that pioneered source control since the 1980s have already observed that small-scale facilities systematically implemented over a catchment are able to influence its hydrological behaviour. This capability is the main strength of source control, as it allows compensation for the negative effects of urbanization. Yet, it also represents its main risk: if initial decision-making is not sufficiently accurate, source control can produce long-term negative effects. Because of its current spreading, source control will acquire an increasing role as a driver of hydrological changes in urban catchments, and the directions of these changes depend on current policy-making practices. This paper presents an analysis and a critical discussion of the main objectives that policy-makers attribute to stormwater source control. The investigation is based on a sample of French case studies, completed by a literature review for international comparison. It identifies four main objectives, some typical of urban stormwater management and some more innovative: flood reduction, receiving waters protection, sustainable development, costs reduction. The discussion focuses on how current policy-making practices are able to translate these objectives in concrete policy instruments, and on which knowledge and tools could improve this process. It is shown that for some objectives, basic knowledge is available, but the creation of policy instruments which are effective at the catchment scale and adapted to local conditions is still problematic. For other objectives, substantial lacks of knowledge exist, casting doubts on long-term effectiveness of current policy

Wind turbine sound pressure level calculations at dwellings.

Science.gov (United States)

Keith, Stephen E; Feder, Katya; Voicescu, Sonia A; Soukhovtsev, Victor; Denning, Allison; Tsang, Jason; Broner, Norm; Leroux, Tony; Richarz, Werner; van den Berg, Frits

2016-03-01

This paper provides calculations of outdoor sound pressure levels (SPLs) at dwellings for 10 wind turbine models, to support Health Canada's Community Noise and Health Study. Manufacturer supplied and measured wind turbine sound power levels were used to calculate outdoor SPL at 1238 dwellings using ISO [(1996). ISO 9613-2-Acoustics] and a Swedish noise propagation method. Both methods yielded statistically equivalent results. The A- and C-weighted results were highly correlated over the 1238 dwellings (Pearson's linear correlation coefficient r > 0.8). Calculated wind turbine SPLs were compared to ambient SPLs from other sources, estimated using guidance documents from the United States and Alberta, Canada.

Vespertilionid bats control the width of their biosonar sound beam dynamically during prey pursuit

DEFF Research Database (Denmark)

Jakobsen, Lasse; Surlykke, Annemarie

2010-01-01

Animals using sound for communication emit directional signals, focusing most acoustic energy in one direction. Echolocating bats are listening for soft echoes from insects. Therefore, a directional biosonar sound beam greatly increases detection probability in the forward direction and decreases...

Orphan sources control in the Republic of Korea

International Nuclear Information System (INIS)

Kim, C.-W.

2001-01-01

In this paper, the orphan source control programme in Korea will be discussed. Orphan sources are, in general, classified into three groups: 1) Illegally trafficking radioactive sources; 2) Domestic loss of radioactive sources due to the bankruptcy of licensees or authorized suppliers; and 3) Contaminated metal scrap, which has been imported. There are, currently, two approaches going on to control and manage orphan sources in Korea. First, the Korean regulatory authority (Ministry of Science and Technology: MOST) will fully run an information system on radiation safety to effectively trace and monitor all radioactive sources in the country by the year 2001. Second, the regulatory authority strongly advises steel mill companies to closely scrutinize and inspect scrap metal through a scrap monitoring system when they attempt to reutilize it in order to prevent it from being contaminated by uncontrolled sources. The Korea Institute of Nuclear Safety (KINS), a regulatory expert organization, is carrying out a three-year multiphase project to control and monitor orphan sources in Korea. The system, called the Information System on Integrated Radiation Safety (ISIRS) on the inter- and intra-net system has been developed to effectively control and accurately monitor radioactive sources on a real time basis since 1998. If the system is successfully set up as scheduled by the middle of May next year, the regulatory authority will be able to control any reutilization of uncontrolled sources efficiently. At the same time, the system can also provide, not only licensees, suppliers, or perspective end users but also the Korean general public of interests with information on radiation safety, safe radiation management tools and public services. The system has been created because of the necessity to effectively control radioactive sources safely. Also, it serves to prepare necessary protective measures in a timely manner for abnormal events of uncontrolled radiation from

Early Sound Symbolism for Vowel Sounds

Directory of Open Access Journals (Sweden)

Ferrinne Spector

2013-06-01

Full Text Available Children and adults consistently match some words (e.g., kiki to jagged shapes and other words (e.g., bouba to rounded shapes, providing evidence for non-arbitrary sound–shape mapping. In this study, we investigated the influence of vowels on sound–shape matching in toddlers, using four contrasting pairs of nonsense words differing in vowel sound (/i/ as in feet vs. /o/ as in boat and four rounded–jagged shape pairs. Crucially, we used reduplicated syllables (e.g., kiki vs. koko rather than confounding vowel sound with consonant context and syllable variability (e.g., kiki vs. bouba. Toddlers consistently matched words with /o/ to rounded shapes and words with /i/ to jagged shapes (p < 0.01. The results suggest that there may be naturally biased correspondences between vowel sound and shape.

Controllable Micro-Particle Rotation and Transportation Using Sound Field Synthesis Technique

Directory of Open Access Journals (Sweden)