WorldWideScience

Sample records for underwater hearing abilities

  1. Underwater Hearing in Turtles.

    Science.gov (United States)

    Willis, Katie L

    2016-01-01

    The hearing of turtles is poorly understood compared with the other reptiles. Although the mechanism of transduction of sound into a neural signal via hair cells has been described in detail, the rest of the auditory system is largely a black box. What is known is that turtles have higher hearing thresholds than other reptiles, with best frequencies around 500 Hz. They also have lower underwater hearing thresholds than those in air, owing to resonance of the middle ear cavity. Further studies demonstrated that all families of turtles and tortoises share a common middle ear cavity morphology, with scaling best suited to underwater hearing. This supports an aquatic origin of the group. Because turtles hear best under water, it is important to examine their vulnerability to anthropogenic noise. However, the lack of basic data makes such experiments difficult because only a few species of turtles have published audiograms. There are also almost no behavioral data available (understandable due to training difficulties). Finally, few studies show what kinds of sounds are behaviorally relevant. One notable paper revealed that the Australian snake-necked turtle (Chelodina oblonga) has a vocal repertoire in air, at the interface, and under water. Findings like these suggest that there is more to the turtle aquatic auditory scene than previously thought.

  2. In-air and underwater hearing of the cormorant

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Wahlberg, Magnus; Christensen-Dalsgaard, Jakob

    Numerous studies have mapped the hearing abilities of birds in air but currently there is little or no data on how diving birds hear or react to sound under water. Therefore, it is unknown whether the ears and auditory system of diving birds are adapted to underwater hearing. In the present study...... 10 cm under water in a large water filled-tank while being artificially ventilated. ABR-responses to calibrated tone bursts produced by a woofer and an underwater speaker, respectively, were measured at different intensities and frequencies to obtain hearing threshold values in air and under water......Hz) under water. Generally, the cormorant ear was not very sensitive to sound, neither in air nor under water. The hearing abilities in water, however, were better than what would have been expected for a purely in-air adapted ear. (Supported by the Carlsberg Foundation 2009_01_0292 and the Danish Council...

  3. In-air and underwater hearing in the great cormorant (Phalacrocorax carbo)

    DEFF Research Database (Denmark)

    Johansen, Sasia; Larsen, Ole Næsbye; Christensen-Dalsgaard, Jakob

    2013-01-01

    The in-air and underwater hearing abilities of the great cormorant was measured using psychophysical and physiological techniques. The threshold of hearing was established at 3 frequencies in air and 4 frequencies underwater using a go-no go staircase psychophysical paradigm in an outdoor pen...... compared to other similar-sized birds. The hearing abilities in water are better than what would have been expected for a purely in-air adapted ear. [Work funded by the Carlsberg Foundation.]...

  4. Underwater hearing in the great cormorant (Phalacrocorax carbo sinensis)

    DEFF Research Database (Denmark)

    Hansen, Kirstin Anderson; Larsen, Ole Næsbye; Wahlberg, Magnus

    2016-01-01

    The underwater hearing threshold of a great cormorant (Phalacrocroax carbo sinensis) was measured at 2 kHz using psychophysical methods. Previous in-air and underwater testing suggests that cormorants have rather poor in-air hearing compared to other birds of similar size (Johansen, 2016). Prelim......The underwater hearing threshold of a great cormorant (Phalacrocroax carbo sinensis) was measured at 2 kHz using psychophysical methods. Previous in-air and underwater testing suggests that cormorants have rather poor in-air hearing compared to other birds of similar size (Johansen, 2016...

  5. Amphibious hearing in ringed seals (Pusa hispida): underwater audiograms, aerial audiograms and critical ratio measurements.

    Science.gov (United States)

    Sills, Jillian M; Southall, Brandon L; Reichmuth, Colleen

    2015-07-01

    Ringed seals (Pusa hispida) are semi-aquatic marine mammals with a circumpolar Arctic distribution. In this study, we investigate the amphibious hearing capabilities of ringed seals to provide auditory profiles for this species across the full range of hearing. Using psychophysical methods with two trained ringed seals, detection thresholds for narrowband signals were measured under quiet, carefully controlled environmental conditions to generate aerial and underwater audiograms. Masked underwater thresholds were measured in the presence of octave-band noise to determine critical ratios. Results indicate that ringed seals possess hearing abilities comparable to those of spotted seals (Phoca largha) and harbor seals (Phoca vitulina), and considerably better than previously reported for ringed and harp seals. Best sensitivity was 49 dB re. 1 µPa (12.8 kHz) in water, and -12 dB re. 20 µPa (4.5 kHz) in air, rivaling the acute hearing abilities of some fully aquatic and terrestrial species in their respective media. Critical ratio measurements ranged from 14 dB at 0.1 kHz to 31 dB at 25.6 kHz, suggesting that ringed seals--like other true seals--can efficiently extract signals from background noise across a broad range of frequencies. The work described herein extends similar research on amphibious hearing in spotted seals recently published by the authors. These parallel studies enhance our knowledge of the auditory capabilities of ice-living seals, and inform effective management strategies for these and related species in a rapidly changing Arctic environment. © 2015. Published by The Company of Biologists Ltd.

  6. The aquatic tympanic ear: convergent adaptations for underwater hearing in three tetrapods

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Wahlberg, Magnus; Larsen, Ole Næsbye

    pressure, low particle motion medium, and the consequence is that an efficient underwater ear is sensitive to sound pressure. It is often stated that underwater hearing can work efficiently without a middle ear apparatus by bone conduction, since sound is transmitted from water to inner ear tissue...... with little loss. However, the sensitivity of such an ear is limited by the very low particle motion in water. We report on underwater hearing in tetrapods ranging from totally aquatic (the clawed frog Xenopus laevis) and mostly aquatic (the red-eared slider Trachemys scripta) to mostly terrestrial (the...... is modified (cartilaginous or partly cartilaginous). In all three species, the lowest threshold to underwater sound is at this peak frequency and is around 80 dB re 1 µPa. The sensitivity to sound pressure is slightly lower in water than in air, making underwater hearing much more efficient in terms of sound...

  7. Specialization for underwater hearing by the tympanic middle ear of the turtle, Trachemys scripta elegans

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J.; Brandt, Christian; Willis, K. L.

    2012-01-01

    Turtles, like other amphibious animals, face a trade-off between terrestrial and aquatic hearing. We used laser vibrometry and auditory brainstem responses to measure their sensitivity to vibration stimuli and to airborne versus underwater sound. Turtles are most sensitive to sound underwater...

  8. Underwater hearing sensitivity of a male and a female Steller sea lion (Eumetopias jubatus)

    NARCIS (Netherlands)

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

    2005-01-01

    The unmasked underwater hearing sensitivities of an 8-year-old male and a 7-year-old female Steller sea lion were measured in a pool, by using behavioral psychophysics. The animals were trained with positive reinforcement to respond when they detected an acoustic signal and not to respond when they

  9. Underwater hearing sensivity of a male and female Steller sea lion (Eumetopias jubatus)

    NARCIS (Netherlands)

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

    2005-01-01

    The unmasked underwater hearing sensitivities of an 8-year-old male and a 7-year-old female Steller sea lion were measured in a pool, by using behavioral psychophysics. The animals were trained with positive reinforcement to respond when they detected an acoustic signal and not to respond when they

  10. Biophysics of underwater hearing in the clawed frog, Xenopus laevis

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Elepfandt, A

    1995-01-01

    Anesthetized clawed frogs (Xenopus laevis) were stimulated with underwater sound and the tympanic disk vibrations were studied using laser vibrometry. The tympanic disk velocities ranged from 0.01 to 0.5 mm/s (at a sound pressure of 2 Pa) in the frequency range of 0.4-4 kHz and were 20-40 dB higher...

  11. Towards Objective Measures of Functional Hearing Abilities

    DEFF Research Database (Denmark)

    Innes-Brown, Hamish; Tsongas, Renee; Marozeau, Jeremy

    2016-01-01

    Aims People with impaired hearing often have difficulties in hearing sounds in a noisy background. This problem is partially a result of the auditory systems reduced capacity to process temporal information in the sound signal. In this study we examined the relationships between perceptual sensit...

  12. Relations between psychophysical measures of spatial hearing and self-reported spatial-hearing abilities

    NARCIS (Netherlands)

    van Esch, T. E. M.; Lutman, M. E.; Vormann, M.; Lyzenga, J.; Hällgren, M.; Larsby, B.; Athalye, S. P.; Houtgast, T.; Kollmeier, B.; Dreschler, W. A.

    2015-01-01

    Objective: The aim of the present study was to investigate how well the virtual psychophysical measures of spatial hearing from the preliminary auditory profile predict self-reported spatial-hearing abilities. Design: Virtual spatial-hearings tests (conducted unaided, via headphones) and a

  13. Pragmatic Abilities of Children with Hearing Loss Using Cochlear Implants or Hearing Aids Compared to Hearing Children

    Science.gov (United States)

    Most, Tova; Shina-August, Ella; Meilijson, Sara

    2010-01-01

    This study characterized the profile of pragmatic abilities among 24 children with hearing loss (HL) aged 6.3-9.4 years, 13 using hearing aids (HAs) and 11 using cochlear implants (CIs), in comparison to those of 13 hearing children with similar chronological and language ages. All the children with HL used spoken language, attended regular…

  14. Cognitive Abilities Relate to Self-Reported Hearing Disability

    Science.gov (United States)

    Zekveld, Adriana A.; George, Erwin L. J.; Houtgast, Tammo; Kramer, Sophia E.

    2013-01-01

    Purpose: In this explorative study, the authors investigated the relationship between auditory and cognitive abilities and self-reported hearing disability. Method: Thirty-two adults with mild to moderate hearing loss completed the Amsterdam Inventory for Auditory Disability and Handicap (AIADH; Kramer, Kapteyn, Festen, & Tobi, 1996) and…

  15. Cognitive abilities relate to self-reported hearing disability

    NARCIS (Netherlands)

    Zekveld, A.A.; George, E.L.J.; Houtgast, T.; Kramer, S.E.

    2013-01-01

    Purpose: In this explorative study, the authors investigated the relationship between auditory and cognitive abilities and self-reported hearing disability. Method: Thirty-two adults with mild to moderate hearing loss completed the Amsterdam Inventory for Auditory Disability and Handicap (AIADH;

  16. Hearing ability in Danish symphony orchestra musicians

    DEFF Research Database (Denmark)

    Obeling, Lise; Poulsen, Torben

    1999-01-01

    equipment placed in various instrument groups. The average audiogram showed a decrease at higher frequencies similar to an age-related hearing loss. Each audiogram was corrected for the age of the person by means of the median from ISO 7029 and the average audiogram from these age-corrected individual...... audiograms showed no signs of hearing loss. The audiograms were also compared to the expected audiograms from ISO 1999, which takes account of the number of years at work, the number of playing hours per week, and the average sound level in the orchestra for the instrument group. In almost all cases...... the measured audiograms looked better than the predictions from ISO 1999. It may be concluded from this investigation that musicians cannot be expected to get pronounced audiometric hearing losses from playing in a symphony orchestra. It should be noted, though, that the data material is limited...

  17. Stereotype threat lowers older adults’ self-reported hearing abilities

    Science.gov (United States)

    Barber, Sarah J.; Lee, Soohyoung Rain

    2016-01-01

    Background Although stereotype threat is a well-documented phenomenon, previous studies examining it in older adults have almost exclusively focused on objective cognitive outcomes. Considerably less attention has been paid to the impact of stereotype threat on older adults’ subjective assessments of their own abilities or to the impact of stereotype threat in non-cognitive domains. Objective Older adults are stereotyped as having experienced not only cognitive declines, but physical declines as well. The current study tested the prediction that stereotype threat can negatively influence older adult's subjective hearing abilities. Methods To test this, 115 adults (M age = 50.02, range = 41-67) read either a positive or negative description about how aging affects hearing. All participants then answered a questionnaire in which they assessed their own hearing abilities. Results The impact of stereotype threat on self-reported hearing was moderated by chronological age. Participants in their 40's and early 50's were unaffected by the stereotype threat manipulation. In contrast, participants in their late 50's and 60's rated their hearing as being subjectively worse when under stereotype threat. Conclusion The current study provides a clear demonstration that stereotype threat negatively impacts older adults’ subjective assessments of their own abilities. It is also the first study to demonstrate an effect of stereotype threat within the domain of hearing. These results have important implications for researchers investigating age-related hearing decline. Stereotype threat can lead to overestimation of the prevalence of age-related hearing decline. It can also serve as a confounding variable when examining the psychosocial correlates of hearing loss. Because of this, researchers studying age-related hearing loss should aim to provide a stereotype-threat free testing environment and also include assessments of stereotype threat within their studies. PMID:26461273

  18. Stereotype Threat Lowers Older Adults' Self-Reported Hearing Abilities.

    Science.gov (United States)

    Barber, Sarah J; Lee, Soohyoung Rain

    2015-01-01

    Although stereotype threat is a well-documented phenomenon, previous studies examining it in older adults have almost exclusively focused on objective cognitive outcomes. Considerably less attention has been paid to the impact of stereotype threat on older adults' subjective assessments of their own abilities or to the impact of stereotype threat in noncognitive domains. Older adults are stereotyped as having experienced not only cognitive declines, but physical declines as well. The current study tested the prediction that stereotype threat can negatively influence older adults' subjective hearing abilities. To test this, 115 adults (mean age 50.03 years, range 41-67) read either a positive or negative description about how aging affects hearing. All participants then answered a questionnaire in which they assessed their own hearing abilities. The impact of stereotype threat on self-reported hearing was moderated by chronological age. Participants in their 40s and early 50s were unaffected by the stereotype threat manipulation. In contrast, participants in their late 50s and 60s rated their hearing as being subjectively worse when under stereotype threat. The current study provides a clear demonstration that stereotype threat negatively impacts older adults' subjective assessments of their own abilities. It is also the first study to demonstrate an effect of stereotype threat within the domain of hearing. These results have important implications for researchers investigating age-related hearing decline. Stereotype threat can lead to overestimation of the prevalence of age-related hearing decline. It can also serve as a confounding variable when examining the psychosocial correlates of hearing loss. Because of this, researchers studying age-related hearing loss should aim to provide a stereotype threat-free testing environment and also include assessments of stereotype threat within their studies. © 2015 S. Karger AG, Basel.

  19. Airborne and underwater hearing in the great cormorant (Phalacrocorax carbo) studied with ABR and laser vibrometry

    DEFF Research Database (Denmark)

    Huulvej, Tina; Wahlberg, Magnus; Christensen-Dalsgaard, Jakob

    mapped the hearing abilities of birds in air, but currently there is little or no data, physiological, psychophysical or behavioral, on how diving birds hear or react to sound under water. Therefore, it is unknown whether the ears of diving birds are adapted to hearing under water and to what extent...... anthropogenic noise influences their hearing during a dive. In the present study, we measured the audiogram of cormorants in air and under water and compared the results to biophysical measurements of eardrum vibrations. Methods We obtained audiograms from wild-caught Great Cormorants (Phalacrocorax carbo...

  20. Localization ability with bimodal hearing aids and bilateral cochlear implants

    Science.gov (United States)

    Seeber, Bernhard U.; Baumann, Uwe; Fastl, Hugo

    2004-09-01

    After successful cochlear implantation in one ear, some patients continue to use a hearing aid at the contralateral ear. They report an improved reception of speech, especially in noise, as well as a better perception of music when the hearing aid and cochlear implant are used in this bimodal combination. Some individuals in this bimodal patient group also report the impression of an improved localization ability. Similar experiences are reported by the group of bilateral cochlear implantees. In this study, a survey of 11 bimodally and 4 bilaterally equipped cochlear implant users was carried out to assess localization ability. Individuals in the bimodal implant group were all provided with the same type of hearing aid in the opposite ear, and subjects in the bilateral implant group used cochlear implants of the same manufacturer on each ear. Subjects adjusted the spot of a computer-controlled laser-pointer to the perceived direction of sound incidence in the frontal horizontal plane by rotating a trackball. Two subjects of the bimodal group who had substantial residual hearing showed localization ability in the bimodal configuration, whereas using each single device only the subject with better residual hearing was able to discriminate the side of sound origin. Five other subjects with more pronounced hearing loss displayed an ability for side discrimination through the use of bimodal aids, while four of them were already able to discriminate the side with a single device. Of the bilateral cochlear implant group one subject showed localization accuracy close to that of normal hearing subjects. This subject was also able to discriminate the side of sound origin using the first implanted device alone. The other three bilaterally equipped subjects showed limited localization ability using both devices. Among them one subject demonstrated a side-discrimination ability using only the first implanted device.

  1. Ontogenetic investigation of underwater hearing capabilities in loggerhead sea turtles (Caretta caretta) using a dual testing approach.

    Science.gov (United States)

    Lavender, Ashley L; Bartol, Soraya M; Bartol, Ian K

    2014-07-15

    Sea turtles reside in different acoustic environments with each life history stage and may have different hearing capacity throughout ontogeny. For this study, two independent yet complementary techniques for hearing assessment, i.e. behavioral and electrophysiological audiometry, were employed to (1) measure hearing in post-hatchling and juvenile loggerhead sea turtles Caretta caretta (19-62 cm straight carapace length) to determine whether these migratory turtles exhibit an ontogenetic shift in underwater auditory detection and (2) evaluate whether hearing frequency range and threshold sensitivity are consistent in behavioral and electrophysiological tests. Behavioral trials first required training turtles to respond to known frequencies, a multi-stage, time-intensive process, and then recording their behavior when they were presented with sound stimuli from an underwater speaker using a two-response forced-choice paradigm. Electrophysiological experiments involved submerging restrained, fully conscious turtles just below the air-water interface and recording auditory evoked potentials (AEPs) when sound stimuli were presented using an underwater speaker. No significant differences in behavior-derived auditory thresholds or AEP-derived auditory thresholds were detected between post-hatchling and juvenile sea turtles. While hearing frequency range (50-1000/1100 Hz) and highest sensitivity (100-400 Hz) were consistent in audiograms pooled by size class for both behavior and AEP experiments, both post-hatchlings and juveniles had significantly higher AEP-derived than behavior-derived auditory thresholds, indicating that behavioral assessment is a more sensitive testing approach. The results from this study suggest that post-hatchling and juvenile loggerhead sea turtles are low-frequency specialists, exhibiting little differences in threshold sensitivity and frequency bandwidth despite residence in acoustically distinct environments throughout ontogeny. © 2014

  2. Auditory Temporal-Organization Abilities in School-Age Children with Peripheral Hearing Loss

    Science.gov (United States)

    Koravand, Amineh; Jutras, Benoit

    2013-01-01

    Purpose: The objective was to assess auditory sequential organization (ASO) ability in children with and without hearing loss. Method: Forty children 9 to 12 years old participated in the study: 12 with sensory hearing loss (HL), 12 with central auditory processing disorder (CAPD), and 16 with normal hearing. They performed an ASO task in which…

  3. Development of a Shortened Version of the Spatial Hearing Questionnaire (SHQ-S) for Screening Spatial-Hearing Ability.

    Science.gov (United States)

    Ou, Hua; Perreau, Ann; Tyler, Richard S

    2017-09-18

    The Spatial Hearing Questionnaire (SHQ) was developed to address how to measure spatial-hearing ability in complex listening situations (Tyler, Perreau, & Ji, 2009). It has been translated and validated into various languages, including Chinese, Dutch, French, and Persian. Although the SHQ contains only 24 items, it could be time-consuming in a busy clinic to administer. The purposes of this study were to develop and validate a shortened version of the SHQ (SHQ-S) and to compare self-perceived spatial-hearing ability across adults with normal hearing (NH), hearing loss (HL), and cochlear implants (CIs). This was a retrospective study. The full version of the SHQ was administered to measure self-perceived spatial-hearing ability for 51 adults with NH at Augustana College, 47 adults with essentially mild to moderately severe sensorineural HL at Illinois State University, and 72 adult CI users at the University of Iowa. Exploratory factor analysis was performed for the full version for the data collected from adults with NH and HL. Appropriate items were chosen to develop the SHQ-S from the results of the exploratory factor analysis. Confirmatory factor analysis was then applied to test the factor structure of the SHQ-S for all participants. One-way analysis of variance was used to compare the self-perceived spatial-hearing performance scores between the 3 groups. The exploratory factor analysis revealed scores loaded on 2 factors. Six items from the full version were chosen accordingly. The results of the confirmatory factor analysis indicated that that a shortened version of 6 items is sufficient to measure spatial-hearing ability. The internal consistency reliability of the SHQ-S was high. The main effect of the one-way analysis of variance was significant for the groups, F(2, 167) = 36.0, p spatial-hearing ability than either the HL or the CI group (both adjusted p values spatial-hearing ability and screening for spatial-hearing difficulties. Participants with NH

  4. Language Outcomes in Children Who Are Deaf and Hard of Hearing: The Role of Language Ability Before Hearing Aid Intervention.

    Science.gov (United States)

    Daub, Olivia; Bagatto, Marlene P; Johnson, Andrew M; Cardy, Janis Oram

    2017-11-09

    Early auditory experiences are fundamental in infant language acquisition. Research consistently demonstrates the benefits of early intervention (i.e., hearing aids) to language outcomes in children who are deaf and hard of hearing. The nature of these benefits and their relation with prefitting development are, however, not well understood. This study examined Ontario Infant Hearing Program birth cohorts to explore predictors of performance on the Preschool Language Scale-Fourth Edition at the time of (N = 47) and after (N = 19) initial hearing aid intervention. Regression analyses revealed that, before the hearing aid fitting, severity of hearing loss negatively predicted 19% and 10% of the variance in auditory comprehension and expressive communication, respectively. After hearing aid fitting, children's standard scores on language measures remained stable, but they made significant improvement in their progress values, which represent individual skills acquired on the test, rather than standing relative to same-age peers. Magnitude of change in progress values was predicted by a negative interaction of prefitting language ability and severity of hearing loss for the Auditory Comprehension scale. These findings highlight the importance of considering a child's prefitting language ability in interpreting eventual language outcomes. Possible mechanisms of hearing aid benefit are discussed. https://doi.org/10.23641/asha.5538868.

  5. Evolution: Fossil Ears and Underwater Sonar.

    Science.gov (United States)

    Lambert, Olivier

    2016-08-22

    A key innovation in the history of whales was the evolution of a sonar system together with high-frequency hearing. Fossils of an archaic toothed whale's inner ear bones provide clues for a stepwise emergence of underwater echolocation ability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effects of Age and Hearing Impairment on the Ability to Benefit from Temporal and Spectral Modulation

    Science.gov (United States)

    Hall, Joseph W.; Buss, Emily; Grose, John H.; Roush, Patricia A.

    2011-01-01

    Objectives At poor signal-to-noise ratios, speech understanding may depend upon the ability to combine speech fragments that are distributed across time and frequency. The goal of this study was to determine the effects of development and hearing impairment on this ability. Design Listeners in the present study included adults and children with normal hearing and with hearing impairment. The children with normal hearing included a younger group (4.6 to 6.9 years of age, n=10) and an older group (7.3 to 11.1 years of age, n=11). The adults with normal hearing were 19–27 years of age (n=10). Adults (19–54 years of age, n=9) and children (7.2 to 10.7 years of age, n=8) with hearing impairment were also tested. The two groups with hearing impairment had comparable mild/moderate bilateral sensorineural hearing impairment. Masked speech reception thresholds for sentences were determined in a baseline condition of steady speech-shaped noise and in noise that was either temporally modulated, spectrally modulated, or both temporally and spectrally modulated. Results The results of normal-hearing listeners indicated higher masked speech reception thresholds for children than adults in steady noise. Adults and children showed the same magnitude of masking release for spectral modulation. Adults showed more masking release than the younger children for temporal modulation, and showed more masking release than both the younger and older children for combined temporal/spectral modulation. Comparing normal-hearing and hearing-impaired listeners, the hearing-impaired listeners had higher masked speech reception thresholds (SRTs) in the steady noise condition and reduced masking release in the modulated noise conditions. Neither the two-way interaction between age and hearing impairment nor the three-way interaction between age, hearing impairment, and masking configuration was significant. Conclusions Although the reduced masking release for temporal modulation shown by the

  7. Influence of hearing loss and cognitive abilities on language development in CHARGE Syndrome

    NARCIS (Netherlands)

    Vesseur, Annemarie; Langereis, Margreet; Free, Rolien; Snik, Ad; van Ravenswaaij-Arts, Conny; Mylanus, Emmanuel

    Hearing loss and cognitive delay are frequently occurring features in CHARGE syndrome that may contribute to impaired language development. However, not much is known about language development in patients with CHARGE syndrome. In this retrospective study, hearing loss, cognitive abilities, and

  8. Evaluation of hearing ability in Danish children at the time of school start and at the end of school

    DEFF Research Database (Denmark)

    Gissel, S.; Mortensen, Jens Tølbøll; Juul, S.

    2002-01-01

    Since previous studies have shown reduced hearing ability in children and adolescents at school start, this study was undertaken to evaluate the hearing ability in Danish children at the time of start and end of school. Children starting school in 1977, 1987, and 1997 from four minor municipalities...... in North Jutland County, Denmark were evaluated for hearing ability by a review of 1,605 school health records. We found a higher prevalence of impaired hearing ability in children who started school 1987 and 1997 compared to those who started school 1977. Reduced hearing was typically at high frequencies....... At the end of school, hearing ability of the year group 1977 was just as poor as for the year group 1987. Whether reduced hearing can influence the learning abilities of these children should be evaluated by further studies including information on the exposure to noise....

  9. Self-monitoring of listening abilities in normal-hearing children, normal-hearing adults, and children with cochlear implants.

    Science.gov (United States)

    Rothpletz, Ann M; Wightman, Frederic L; Kistler, Doris J

    2012-03-01

    Self-monitoring has been shown to be an essential skill for various aspects of our lives, including our health, education, and interpersonal relationships. Likewise, the ability to monitor one's speech reception in noisy environments may be a fundamental skill for communication, particularly for those who are often confronted with challenging listening environments, such as students and children with hearing loss. The purpose of this project was to determine if normal-hearing children, normal-hearing adults, and children with cochlear implants can monitor their listening ability in noise and recognize when they are not able to perceive spoken messages. Participants were administered an Objective-Subjective listening task in which their subjective judgments of their ability to understand sentences from the Coordinate Response Measure corpus presented in speech spectrum noise were compared to their objective performance on the same task. Participants included 41 normal-hearing children, 35 normal-hearing adults, and 10 children with cochlear implants. On the Objective-Subjective listening task, the level of the masker noise remained constant at 63 dB SPL, while the level of the target sentences varied over a 12 dB range in a block of trials. Psychometric functions, relating proportion correct (Objective condition) and proportion perceived as intelligible (Subjective condition) to target/masker ratio (T/M), were estimated for each participant. Thresholds were defined as the T/M required to produce 51% correct (Objective condition) and 51% perceived as intelligible (Subjective condition). Discrepancy scores between listeners' threshold estimates in the Objective and Subjective conditions served as an index of self-monitoring ability. In addition, the normal-hearing children were administered tests of cognitive skills and academic achievement, and results from these measures were compared to findings on the Objective-Subjective listening task. Nearly half of the

  10. The approximate number system and domain-general abilities as predictors of math ability in children with normal hearing and hearing loss.

    Science.gov (United States)

    Bull, Rebecca; Marschark, Marc; Nordmann, Emily; Sapere, Patricia; Skene, Wendy A

    2017-08-29

    Many children with hearing loss (CHL) show a delay in mathematical achievement compared to children with normal hearing (CNH). This study examined whether there are differences in acuity of the approximate number system (ANS) between CHL and CNH, and whether ANS acuity is related to math achievement. Working memory (WM), short-term memory (STM), and inhibition were considered as mediators of any relationship between ANS acuity and math achievement. Seventy-five CHL were compared with 75 age- and gender-matched CNH. ANS acuity, mathematical reasoning, WM, and STM of CHL were significantly poorer compared to CNH. Group differences in math ability were no longer significant when ANS acuity, WM, or STM was controlled. For CNH, WM and STM fully mediated the relationship of ANS acuity to math ability; for CHL, WM and STM only partially mediated this relationship. ANS acuity, WM, and STM are significant contributors to hearing status differences in math achievement, and to individual differences within the group of CHL. Statement of contribution What is already known on this subject? Children with hearing loss often perform poorly on measures of math achievement, although there have been few studies focusing on basic numerical cognition in these children. In typically developing children, the approximate number system predicts math skills concurrently and longitudinally, although there have been some contradictory findings. Recent studies suggest that domain-general skills, such as inhibition, may account for the relationship found between the approximate number system and math achievement. What does this study adds? This is the first robust examination of the approximate number system in children with hearing loss, and the findings suggest poorer acuity of the approximate number system in these children compared to hearing children. The study addresses recent issues regarding the contradictory findings of the relationship of the approximate number system to math ability

  11. Musicians′ ability to judge the risk of acquiring noise induced hearing loss

    Directory of Open Access Journals (Sweden)

    Björn Hagerman

    2013-01-01

    Full Text Available The objective of this research was to study musicians′ abilities to estimate the risk to obtain a hearing loss. Twenty-two professional musicians mainly playing classical music wore dosimeters during 2 working weeks. They also wrote a diary describing all their musical activities and tried to judge the percentage of time that every activity was harmful to their hearing. Half of the musicians seemed to be capable to reasonably judge the harmfulness of the music that they were exposed to. They started to judge the levels to be risky at 80 dB(A and regarded themselves as sligthly more susceptible to noise induced hearing loss than normal.

  12. Age-related changes in auditory and cognitive abilities in elderly persons with hearing aids fitted at the initial stages of hearing loss

    Directory of Open Access Journals (Sweden)

    C. Obuchi

    2011-03-01

    Full Text Available In this study, we investigated the relation between the use of hearing aids at the initial stages of hearing loss and age-related changes in the auditory and cognitive abilities of elderly persons. 12 healthy elderly persons participated in an annual auditory and cognitive longitudinal examination for three years. According to their hearing level, they were divided into 3 subgroups - the normal hearing group, the hearing loss without hearing aids group, and the hearing loss with hearing aids group. All the subjects underwent 4 tests: pure-tone audiometry, syllable intelligibility test, dichotic listening test (DLT, and Wechsler Adult Intelligence Scale-Revised (WAIS-R Short Forms. Comparison between the 3 groups revealed that the hearing loss without hearing aids group showed the lowest scores for the performance tasks, in contrast to the hearing level and intelligibility results. The other groups showed no significant difference in the WAIS-R subtests. This result indicates that prescription of a hearing aid during the early stages of hearing loss is related to the retention of cognitive abilities in such elderly people. However, there were no statistical significant correlations between the auditory and cognitive tasks.

  13. The role of hearing ability and speech distortion in the facilitation of articulatory motor cortex.

    Science.gov (United States)

    Nuttall, Helen E; Kennedy-Higgins, Daniel; Devlin, Joseph T; Adank, Patti

    2017-01-08

    Excitability of articulatory motor cortex is facilitated when listening to speech in challenging conditions. Beyond this, however, we have little knowledge of what listener-specific and speech-specific factors engage articulatory facilitation during speech perception. For example, it is unknown whether speech motor activity is independent or dependent on the form of distortion in the speech signal. It is also unknown if speech motor facilitation is moderated by hearing ability. We investigated these questions in two experiments. We applied transcranial magnetic stimulation (TMS) to the lip area of primary motor cortex (M1) in young, normally hearing participants to test if lip M1 is sensitive to the quality (Experiment 1) or quantity (Experiment 2) of distortion in the speech signal, and if lip M1 facilitation relates to the hearing ability of the listener. Experiment 1 found that lip motor evoked potentials (MEPs) were larger during perception of motor-distorted speech that had been produced using a tongue depressor, and during perception of speech presented in background noise, relative to natural speech in quiet. Experiment 2 did not find evidence of motor system facilitation when speech was presented in noise at signal-to-noise ratios where speech intelligibility was at 50% or 75%, which were significantly less severe noise levels than used in Experiment 1. However, there was a significant interaction between noise condition and hearing ability, which indicated that when speech stimuli were correctly classified at 50%, speech motor facilitation was observed in individuals with better hearing, whereas individuals with relatively worse but still normal hearing showed more activation during perception of clear speech. These findings indicate that the motor system may be sensitive to the quantity, but not quality, of degradation in the speech signal. Data support the notion that motor cortex complements auditory cortex during speech perception, and point to a role

  14. Bilateral bone conduction devices: improved hearing ability in children with bilateral conductive hearing loss.

    Science.gov (United States)

    Dun, Catharina A J; Agterberg, Martijn J H; Cremers, Cor W R J; Hol, Myrthe K S; Snik, Ad F M

    2013-01-01

    The aim of the study was to investigate whether children with bilateral conductive hearing loss benefit from their second device (i.e., the bilateral bone conduction device [BCD]). Speech recognition in noise was assessed in 10 children fitted with bilateral BCDs during childhood. Speech recognition was measured in 2 conditions with both BCDs active. Spatial resolution was tested with the Minimum Audible Angle test in the bilateral and monaural listening conditions. Children demonstrated an improvement in speech recognition when speech was presented from the front and noise was presented from the right-hand side as compared with both speech and noise being presented from the front. The minimum audible angle decreased from 57° in the best monaural condition to 13° in the bilateral condition. The audiological outcomes demonstrate the advantage of bilateral BCD fitting in children with bilateral conductive hearing loss.

  15. Binaural Hearing-Human Ability of Sound Source Localization

    OpenAIRE

    Parhizkari, Parvaneh

    2009-01-01

    Abstract The purpose of this project is to desig a systematical method in order to measure human directionality ability in horizontal plane with a single sound source. A completely virtual auditory model has been created in Matlab. The project consists of modeling binaural cues, designing digital filters, designing a test workbench, measuring listener's directionality and analyzing the data. The head related transfer function (HRTF) is computed by calculating the two most important binau...

  16. Enhancing Sequential Time Perception and Storytelling Ability of Deaf and Hard of Hearing Children

    Science.gov (United States)

    Ingber, Sara; Eden, Sigal

    2011-01-01

    A 3-month intervention was conducted to enhance the sequential time perception and storytelling ability of young children with hearing loss. The children were trained to arrange pictorial episodes of temporal scripts and tell the stories they created. Participants (N = 34, aged 4-7 years) were divided into 2 groups based on whether their…

  17. Relationship between lead in the blood and performance in the abilities from hearing process

    Directory of Open Access Journals (Sweden)

    Gonçalves, Thaís dos Santos

    2012-01-01

    Full Text Available Introduction: The contamination by lead affects all the nervous systems from the human body, mostly the nervous system. Objective: Investigate if there is correlation between the blood lead levels and the performance in tests of hearing process. Method: Retrospective study. 73 children, with ages between 7 to 15 years, residents in a area where happened emission of lead above the permitted, with level of blood lead level bigger or equal to 10 micrograms/dL, audiological exams (audiometry and tympanometry inside the normality patterns. To evaluate the hearing process were used the Auditory Fusion Test-Revised (AFT-R, subtest 1, and the dichotic test of digits (binaural integration stage. Was used the Spearman test to verify the correlation between the data. Results: The blood lead level varieties from 10 to 30,2 micrograms/dL, being the average corresponding to 15,8 micrograms/dL (standard deviation of 4,8. From those children, 60,3% presented a bad performance for the right ear and 67,3% presented a bad performance of the left ear. According to the results of the tests of correlation of Spearman, there were no significant statistical between the level of lead and the results of hearing processing tests. Conclusion: There were no correlation between the blood lead level and the performance in the abilities of the hearing process; however the contaminated children by the lead presented a lower performance in the abilities of the hearing processing.

  18. Hearing Ability in Working Life and Its Relationship With Sick Leave and Self-Reported Work Productivity

    NARCIS (Netherlands)

    Nachtegaal, J.; Festen, J.M.; Kramer, S.E.

    2012-01-01

    Objectives: Reduced hearing ability has been shown to influence various aspects of daily life, such as communication, psychosocial functioning, and working life. The aim of this study is to examine the association between hearing ability in noise and both sick leave and self-reported work

  19. Peripheral hearing loss reduces the ability of children to direct selective attention during multi-talker listening.

    Science.gov (United States)

    Holmes, Emma; Kitterick, Padraig T; Summerfield, A Quentin

    2017-07-01

    Restoring normal hearing requires knowledge of how peripheral and central auditory processes are affected by hearing loss. Previous research has focussed primarily on peripheral changes following sensorineural hearing loss, whereas consequences for central auditory processing have received less attention. We examined the ability of hearing-impaired children to direct auditory attention to a voice of interest (based on the talker's spatial location or gender) in the presence of a common form of background noise: the voices of competing talkers (i.e. during multi-talker, or "Cocktail Party" listening). We measured brain activity using electro-encephalography (EEG) when children prepared to direct attention to the spatial location or gender of an upcoming target talker who spoke in a mixture of three talkers. Compared to normally-hearing children, hearing-impaired children showed significantly less evidence of preparatory brain activity when required to direct spatial attention. This finding is consistent with the idea that hearing-impaired children have a reduced ability to prepare spatial attention for an upcoming talker. Moreover, preparatory brain activity was not restored when hearing-impaired children listened with their acoustic hearing aids. An implication of these findings is that steps to improve auditory attention alongside acoustic hearing aids may be required to improve the ability of hearing-impaired children to understand speech in the presence of competing talkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The relative contributions of speechreading and vocabulary to deaf and hearing children's reading ability.

    Science.gov (United States)

    Kyle, Fiona Elizabeth; Campbell, Ruth; MacSweeney, Mairéad

    2016-01-01

    Vocabulary knowledge and speechreading are important for deaf children's reading development but it is unknown whether they are independent predictors of reading ability. This study investigated the relationships between reading, speechreading and vocabulary in a large cohort of deaf and hearing children aged 5 to 14 years. 86 severely and profoundly deaf children and 91 hearing children participated in this study. All children completed assessments of reading comprehension, word reading accuracy, speechreading and vocabulary. Regression analyses showed that vocabulary and speechreading accounted for unique variance in both reading accuracy and comprehension for deaf children. For hearing children, vocabulary was an independent predictor of both reading accuracy and comprehension skills but speechreading only accounted for unique variance in reading accuracy. Speechreading and vocabulary are important for reading development in deaf children. The results are interpreted within the Simple View of Reading framework and the theoretical implications for deaf children's reading are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Impact of cognitive and linguistic ability on gaze behavior in children with hearing impairment

    Directory of Open Access Journals (Sweden)

    Olof eSandgren

    2013-11-01

    Full Text Available In order to explore verbal-nonverbal integration, we investigated the influence of cognitive and linguistic ability on gaze behavior during spoken language conversation between children with mild-to-moderate hearing impairment (HI and normal-hearing (NH peers. Ten HI-NH and ten NH-NH dyads performed a referential communication task requiring description of faces. During task performance, eye movements and speech were tracked. Cox proportional hazards regression was used to model associations between performance on cognitive and linguistic tasks and the probability of gaze to the conversational partner’s face. Analyses compare the listeners in each dyad (HI: n = 10, mean age = 12;6 years, SD = 2;0, mean better ear pure-tone average 33.0 dB HL, SD = 7.8; NH: n = 10, mean age = 13;7 years, SD = 1;11. Group differences in gaze behavior – with HI gazing more to the conversational partner than NH – remained significant despite adjustment for ability on receptive grammar, expressive vocabulary, and complex working memory. Adjustment for phonological short term memory, as measured by nonword repetition, removed group differences, revealing an interaction between group membership and nonword repetition ability. Stratified analysis showed a twofold increase of the probability of gaze-to-partner for HI with low phonological short term memory capacity, and a decreased probability for HI with high capacity, as compared to NH peers. The results revealed differences in gaze behavior attributable to performance on a phonological short term memory task. Participants with hearing impairment and low phonological short term memory capacity showed a doubled probability of gaze to the conversational partner, indicative of a visual bias. The results stress the need to look beyond the hearing impairment in diagnostics and intervention. Acknowledgment of the finding requires clinical assessment of children with hearing impairment to be supported by tasks tapping

  2. The effect of signal duration on the underwater hearing thresholds of two harbor seals (Phoca vitulina) for single tonal signals between 0.2 and 40 kHz

    NARCIS (Netherlands)

    Kastelein, R.A.; Hoek, L.; Wensveen, P.J.; Terhune, J.M.; Jong, C.A.F. de

    2010-01-01

    The underwater hearing sensitivities of two 2-year-old female harbor seals were quantified in a pool built for acoustic research by using a behavioral psycho-acoustic technique. The animals were trained only to respond when they detected an acoustic signal (“go/no-go” response). Detection thresholds

  3. Ontogenetic development of weberian ossicles and hearing abilities in the African bullhead catfish.

    Directory of Open Access Journals (Sweden)

    Walter Lechner

    Full Text Available BACKGROUND: The weberian apparatus of otophysine fishes facilitates sound transmission from the swimbladder to the inner ear to increase hearing sensitivity. It has been of great interest to biologists since the 19(th century. No studies, however, are available on the development of the weberian ossicles and its effect on the development of hearing in catfishes. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the development of the weberian apparatus and auditory sensitivity in the catfish Lophiobagrus cyclurus. Specimens from 11.3 mm to 85.5 mm in standard length were studied. Morphology was assessed using sectioning, histology, and X-ray computed tomography, along with 3D reconstruction. Hearing thresholds were measured utilizing the auditory evoked potentials recording technique. Weberian ossicles and interossicular ligaments were fully developed in all stages investigated except in the smallest size group. In the smallest catfish, the intercalarium and the interossicular ligaments were still missing and the tripus was not yet fully developed. Smallest juveniles revealed lowest auditory sensitivity and were unable to detect frequencies higher than 2 or 3 kHz; sensitivity increased in larger specimens by up to 40 dB, and frequency detection up to 6 kHz. In the size groups capable of perceiving frequencies up to 6 kHz, larger individuals had better hearing abilities at low frequencies (0.05-2 kHz, whereas smaller individuals showed better hearing at the highest frequencies (4-6 kHz. CONCLUSIONS/SIGNIFICANCE: Our data indicate that the ability of otophysine fish to detect sounds at low levels and high frequencies largely depends on the development of the weberian apparatus. A significant increase in auditory sensitivity was observed as soon as all weberian ossicles and interossicular ligaments are present and the chain for transmitting sounds from the swimbladder to the inner ear is complete. This contrasts with findings in another otophysine

  4. "Boxnep" advanced modular underwater robot

    OpenAIRE

    Buluev, Ilia

    2016-01-01

    The article discusses the relevance of the underwater vehicles' ability to solve a wide range of problems. The idea put in the basis of this research is designing a modular underwater robot. It allows to mount various equipment and test it in underwater environment. The paper deals with the concept of the robot and its characteristics.

  5. Musical Experience and the Aging Auditory System: Implications for Cognitive Abilities and Hearing Speech in Noise

    Science.gov (United States)

    Parbery-Clark, Alexandra; Strait, Dana L.; Anderson, Samira; Hittner, Emily; Kraus, Nina

    2011-01-01

    Much of our daily communication occurs in the presence of background noise, compromising our ability to hear. While understanding speech in noise is a challenge for everyone, it becomes increasingly difficult as we age. Although aging is generally accompanied by hearing loss, this perceptual decline cannot fully account for the difficulties experienced by older adults for hearing in noise. Decreased cognitive skills concurrent with reduced perceptual acuity are thought to contribute to the difficulty older adults experience understanding speech in noise. Given that musical experience positively impacts speech perception in noise in young adults (ages 18–30), we asked whether musical experience benefits an older cohort of musicians (ages 45–65), potentially offsetting the age-related decline in speech-in-noise perceptual abilities and associated cognitive function (i.e., working memory). Consistent with performance in young adults, older musicians demonstrated enhanced speech-in-noise perception relative to nonmusicians along with greater auditory, but not visual, working memory capacity. By demonstrating that speech-in-noise perception and related cognitive function are enhanced in older musicians, our results imply that musical training may reduce the impact of age-related auditory decline. PMID:21589653

  6. The effect of tinnitus on some psychoacoustical abilities in individuals with normal hearing sensitivity.

    Science.gov (United States)

    Jain, Chandni; Sahoo, Jitesh Prasad

    2014-01-01

    Tinnitus is the perception of a sound without an external source. It can affect auditory perception abilities in individuals with normal hearing sensitivity. The aim of the study was to determine the effect of tinnitus on psychoacoustic abilities in individuals with normal hearing sensitivity. The study was conducted on twenty subjects with tinnitus and twenty subjects without tinnitus. Tinnitus group was again divided into mild and moderate tinnitus based on the tinnitus handicap inventory. Differential limen of intensity, differential limen of frequency, gap detection test, modulation detection thresholds were done through the mlp toolbox in Matlab and speech in noise test was done with the help of Quick SIN in Kannada. RESULTS of the study showed that the clinical group performed poorly in all the tests except for differential limen of intensity. Tinnitus affects aspects of auditory perception like temporal resolution, speech perception in noise and frequency discrimination in individuals with normal hearing. This could be due to subtle changes in the central auditory system which is not reflected in the pure tone audiogram.

  7. Musical experience and the aging auditory system: implications for cognitive abilities and hearing speech in noise.

    Science.gov (United States)

    Parbery-Clark, Alexandra; Strait, Dana L; Anderson, Samira; Hittner, Emily; Kraus, Nina

    2011-05-11

    Much of our daily communication occurs in the presence of background noise, compromising our ability to hear. While understanding speech in noise is a challenge for everyone, it becomes increasingly difficult as we age. Although aging is generally accompanied by hearing loss, this perceptual decline cannot fully account for the difficulties experienced by older adults for hearing in noise. Decreased cognitive skills concurrent with reduced perceptual acuity are thought to contribute to the difficulty older adults experience understanding speech in noise. Given that musical experience positively impacts speech perception in noise in young adults (ages 18-30), we asked whether musical experience benefits an older cohort of musicians (ages 45-65), potentially offsetting the age-related decline in speech-in-noise perceptual abilities and associated cognitive function (i.e., working memory). Consistent with performance in young adults, older musicians demonstrated enhanced speech-in-noise perception relative to nonmusicians along with greater auditory, but not visual, working memory capacity. By demonstrating that speech-in-noise perception and related cognitive function are enhanced in older musicians, our results imply that musical training may reduce the impact of age-related auditory decline.

  8. Musical experience and the aging auditory system: implications for cognitive abilities and hearing speech in noise.

    Directory of Open Access Journals (Sweden)

    Alexandra Parbery-Clark

    Full Text Available Much of our daily communication occurs in the presence of background noise, compromising our ability to hear. While understanding speech in noise is a challenge for everyone, it becomes increasingly difficult as we age. Although aging is generally accompanied by hearing loss, this perceptual decline cannot fully account for the difficulties experienced by older adults for hearing in noise. Decreased cognitive skills concurrent with reduced perceptual acuity are thought to contribute to the difficulty older adults experience understanding speech in noise. Given that musical experience positively impacts speech perception in noise in young adults (ages 18-30, we asked whether musical experience benefits an older cohort of musicians (ages 45-65, potentially offsetting the age-related decline in speech-in-noise perceptual abilities and associated cognitive function (i.e., working memory. Consistent with performance in young adults, older musicians demonstrated enhanced speech-in-noise perception relative to nonmusicians along with greater auditory, but not visual, working memory capacity. By demonstrating that speech-in-noise perception and related cognitive function are enhanced in older musicians, our results imply that musical training may reduce the impact of age-related auditory decline.

  9. A comparison of pragmatic abilities of children who are deaf or hard of hearing and their hearing peers.

    Science.gov (United States)

    Paatsch, Louise E; Toe, Dianne M

    2014-01-01

    Pragmatic skills are the key to a satisfying and sustained conversation. Such conversation is critical for the development of meaningful friendships. Previous studies have investigated the conversational skills of deaf children while interacting with adults or when interacting with peers in structured referential tasks. There are few published studies that have compared the pragmatic skills of children who are deaf or hard of hearing (D/HH) in free conversation with their hearing peers. In this study, the conversational skills of 31 children who are D/HH when interacting with a hearing friend were compared with those of 31 pairs of hearing children. Findings suggest that school-aged children (Years 3-6 of study; aged 8-12 years) who are D/HH have a wide range of pragmatic skills that they use effectively when conversing with their hearing peers. Specifically, these children asked more questions, made more personal comments, initiated more topics, and took longer turns in their conversations with a hearing friend. In contrast, the conversations between hearing peers were very balanced with similar topic initiation, length of turn, numbers of questions, personal comments, and minimal answers. These findings will help teachers to provide support for both pragmatic and social skills in children who are D/HH.

  10. COMPARISON OF ABILITY OF OPPOSITION WORDS PROCESSING BETWEEN HEARING AND HEARING IMPAIRED STUDENT IN FIFTH GRADE IN TEHRAN

    Directory of Open Access Journals (Sweden)

    B SHAFIEI

    2003-12-01

    Full Text Available Introduction: Hearing impaired Persons have disorders in Communication. Theu are not able to learning many aspects of language Structures in Paroper time; quantity and quality. They can not Process these factors as same as Partners. In this research we going to assess and comparison opposite word in hearing and hearing impaired Student in fifth grade. This is a semantic research.
    Methods: Subjects of this research were hearing impaired students in fifth grade in tehramwohad + 70dbheaing loss in Best Binaural Average and in order to comparison with them, we selected hearing students in fifth grade. In this research four non linguistic factors were investigated (age, sex, words of Farsi language. The subjects must read these words and write an opposite Word in front of it. In this examination the quantity of types: right, false and without answers.
    Findings: The sequence of right answers had significant different in two group. The Sequence of learned words had significant different two groups. The time of processing in hearing students was shorter than hearing impaired students. The female subjects gave right answers more than male subjects. Discussion: The differences between bearing and hearing impaired students were in the quantity of answers specially in right answers and time of doing the test. probably these differences were due to lack of proper lexicon words and/or poor of it. The hearing students had more right answers and were shorter in time of processing.

  11. In-air and underwater hearing in the great cormorant (Phalacrocorax carbo sinensis)

    DEFF Research Database (Denmark)

    Johansen, Sasia; Larsen, Ole Næsbye; Christensen-Dalsgaard, Jakob

    2016-01-01

    Hearing thresholds of a great cormorant (Phalacrocorax carbo) were measured in air and under water using psychophysics. The lowest thresholds were at 2 kHz (45 dB re 20 μPa root-mean-square [rms] in air and 79 dB re 1 μPa rms in water). Auditory brainstem response measurements on one anesthetized...

  12. Hearing ability with age in northern European women: a new web-based approach to genetic studies.

    Directory of Open Access Journals (Sweden)

    Lisa E Wolber

    Full Text Available Age-related hearing impairment (ARHI affects 25-40% of individuals over the age of 65. Despite the high prevalence of this complex trait, ARHI is still poorly understood. We hypothesized that variance in hearing ability with age is largely determined by genetic factors. We collected audiologic data on females of Northern European ancestry and compared different audiogram representations. A web-based speech-to-noise ratio (SNR hearing test was compared with pure-tone thresholds to see if we could determine accurately hearing ability on people at home and the genetic contribution to each trait compared. Volunteers were recruited from the TwinsUK cohort. Hearing ability was determined using pure-tone audiometry and a web-based hearing test. Different audiogram presentations were compared for age-correlation and reflection of audiogram shape. Using structural equation modelling based on the classical twin model the heritability of ARHI, as measured by the different phenotypes, was estimated and shared variance between the web-based SNR test and pure-tone audiometry determined using bivariate modelling. Pure-tone audiometric data was collected on 1033 older females (age: 41-86. 1970 volunteers (males and females, age: 18-85 participated in the SNR. In the comparison between different ARHI phenotypes the difference between the first two principle components (PC1-PC2 best represented ARHI. The SNR test showed a sensitivity and specificity of 89% and 80%, respectively, in comparison with pure-tone audiogram data. Univariate heritability estimates ranged from 0.70 (95% CI: 0.63-0.76 for (PC1-PC2 to 0.56 (95% CI: 0.48-0.63 for PC2. The genetic correlation of PC1-PC2 and SNR was -0.67 showing that the 2 traits share variances attributed to additive genetic factors. Hearing ability showed considerable heritability in our sample. We have shown that the SNR test provides a useful surrogate marker of hearing. This will enable a much larger sample to be

  13. Early Hearing Loss and Language Abilities in Children with Down Syndrome

    Science.gov (United States)

    Laws, Glynis; Hall, Amanda

    2014-01-01

    Background: Although many children with Down syndrome experience hearing loss, there has been little research to investigate its impact on speech and language development. Studies that have investigated the association give inconsistent results. These have often been based on samples where children with the most severe hearing impairments have…

  14. Unilateral and bilateral cochlear implants and the implant-plus-hearing-aid profile: comparing self-assessed and measured abilities.

    Science.gov (United States)

    Noble, William; Tyler, Richard; Dunn, Camille; Bhullar, Navjot

    2008-08-01

    Patients fitted with one (CI) versus two (CI+CI) cochlear implants, and those fitted with one implant who retain a hearing aid in the non-implanted ear (CI+HA), were compared using the speech, spatial, and qualities of hearing scale (SSQ) (Gatehouse & Noble, 2004). The CI+CI profile yielded significantly higher ability ratings than the CI profile in the spatial hearing domain, and on most aspects of other qualities of hearing (segregation, naturalness, and listening effort). A subset of patients completed the SSQ prior to implantation, and the CI+CI profile showed consistently greater improvement than the CI profile across all domains. Patients in the CI+HA group self-rated no differently from the CI group, post-implant. Measured speech perception and localization performance showed some parallels with the self-rating outcomes. Overall, a unilateral CI provided significant benefit across most hearing functions reflected in the SSQ. Bilateral implantation offered further benefit across a substantial range of those functions.

  15. Underwater robots

    CERN Document Server

    Antonelli, Gianluca

    2014-01-01

    This book, now at the third edition, addresses the main control aspects in underwater manipulation tasks. The mathematical model with significant impact on the control strategy is discussed. The problem of controlling a 6-degrees-of-freedoms autonomous underwater vehicle is deeply investigated and a survey of fault detection/tolerant strategies for unmanned underwater vehicles is provided. Inverse kinematics, dynamic and interaction control for underwater vehicle-manipulator systems are then discussed. The code used to generate most of the numerical simulations is made available and briefly discussed.       

  16. THE EFFECT OF MIND MAPPING WITH PICTURE WORD CARDS TOWARD THE ABILITY OF EARLY READING FOR A HARD OF HEARING STUDENT

    Directory of Open Access Journals (Sweden)

    Nurika Miftakul Janah

    2016-12-01

    Full Text Available A Student with hard of hearing hasa limited vocabulary and difficulty understanding abstract words. The purposes of this research were to describe: (1 the ability of early reading for a hard of hearing student at the time before the intervention, (2 the ability of early reading for a hard of hearing student after the intervention, and (3 the effect of mind mapping with picture word card toward the ability of early reading for a hard of hearing student in the class I. This study used a single subject research (SSR with A-B-A design. These results indicated that there was a positive effect of the mind mapping with picture word card toward the ability of early reading for a hard of hearing student in the class I.

  17. Google™ underwater

    Science.gov (United States)

    Showstack, Randy

    2012-10-01

    The first underwater panoramic images were added to Google Maps™, the company announced on 25 September. This first “underwater Street View collection,” launched in partnership with the Caitlin Seaview Survey, provides people with the opportunity to “become the next virtual Jacques Cousteau.” For more information, see: maps.google.com/ocean.

  18. Hearing abilities and sound reception of broadband sounds in an adult Risso's dolphin (Grampus griseus).

    Science.gov (United States)

    Mooney, T Aran; Yang, Wei-Cheng; Yu, Hsin-Yi; Ketten, Darlene R; Jen, I-Fan

    2015-08-01

    While odontocetes do not have an external pinna that guides sound to the middle ear, they are considered to receive sound through specialized regions of the head and lower jaw. Yet odontocetes differ in the shape of the lower jaw suggesting that hearing pathways may vary between species, potentially influencing hearing directionality and noise impacts. This work measured the audiogram and received sensitivity of a Risso's dolphin (Grampus griseus) in an effort to comparatively examine how this species receives sound. Jaw hearing thresholds were lowest (most sensitive) at two locations along the anterior, midline region of the lower jaw (the lower jaw tip and anterior part of the throat). Responses were similarly low along a more posterior region of the lower mandible, considered the area of best hearing in bottlenose dolphins. Left- and right-side differences were also noted suggesting possible left-right asymmetries in sound reception or differences in ear sensitivities. The results indicate best hearing pathways may vary between the Risso's dolphin and other odontocetes measured. This animal received sound well, supporting a proposed throat pathway. For Risso's dolphins in particular, good ventral hearing would support their acoustic ecology by facilitating echo-detection from their proposed downward oriented echolocation beam.

  19. Predicting reading ability in teenagers who are deaf or hard of hearing: A longitudinal analysis of language and reading.

    Science.gov (United States)

    Worsfold, Sarah; Mahon, Merle; Pimperton, Hannah; Stevenson, Jim; Kennedy, Colin

    2018-04-13

    Deaf and hard of hearing (D/HH) children and young people are known to show group-level deficits in spoken language and reading abilities relative to their hearing peers. However, there is little evidence on the longitudinal predictive relationships between language and reading in this population. To determine the extent to which differences in spoken language ability in childhood predict reading ability in D/HH adolescents. and procedures: Participants were drawn from a population-based cohort study and comprised 53 D/HH teenagers, who used spoken language, and a comparison group of 38 normally hearing teenagers. All had completed standardised measures of spoken language (expression and comprehension) and reading (accuracy and comprehension) at 6-10 and 13-19 years of age. and results: Forced entry stepwise regression showed that, after taking reading ability at age 8 years into account, language scores at age 8 years did not add significantly to the prediction of Reading Accuracy z-scores at age 17 years (change in R 2  = 0.01, p = .459) but did make a significant contribution to the prediction of Reading Comprehension z-scores at age 17 years (change in R 2  = 0.17, p skills in middle childhood predict reading comprehension ability in adolescence. Continued intervention to support language development beyond primary school has the potential to benefit reading comprehension and hence educational access for D/HH adolescents. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Otolith morphology and hearing abilities in cave- and surface-dwelling ecotypes of the Atlantic molly, Poecilia mexicana (Teleostei: Poeciliidae)

    Science.gov (United States)

    Schulz-Mirbach, Tanja; Ladich, Friedrich; Riesch, Rüdiger; Plath, Martin

    2010-01-01

    Cave fish have rarely been investigated with regard to their inner ear morphology, hearing abilities, and acoustic communication. Based on a previous study that revealed morphological differences in the saccular otolith between a cave and two surface populations of Poecilia mexicana, we checked for additional differences in utricular and lagenar otoliths and tested whether different populations have similar hearing sensitivities. We found pronounced differences in the shape of all three otoliths. Otoliths of the saccule and lagena from cave fish differed from those of surface fish in the features of the face oriented towards the sensory epithelium. In addition, otoliths of the utricle and lagena were significantly heavier in cave fish. Auditory sensitivities were measured between 100 and 1500 Hz, utilizing the auditory evoked potential recording technique. We found similar hearing abilities in cave and surface fish, with greatest sensitivity between 200 and 300 Hz. An acoustic survey revealed that neither ecotype produced species-specific sounds. Our data indicate that cave dwelling altered the otolith morphology in Atlantic mollies, probably due to metabolic differences. Different otolith morphology, however, did not affect general auditory sensitivity or acoustic behavior. PMID:20430090

  1. Reading and Spelling Abilities of Deaf Adolescents with Cochlear Implants and Hearing Aids

    Science.gov (United States)

    Harris, Margaret; Terlektsi, Emmanouela

    2011-01-01

    A total of 86 deaf children aged between 12 and 16 years were recruited from schools for the deaf, specialist units attached to a school, and mainstream schools. Approximately one-third used hearing aids, one-third had received a cochlear implant before 42 months, and one-third had been implanted later. The 3 subgroups were matched for age and…

  2. Assessing speech recognition abilities with digits in noise in cochlear implant and hearing aid users

    NARCIS (Netherlands)

    Kaandorp, M.W.; Smits, J.C.M.; Merkus, P.; Goverts, S.T.; Festen, J.M.

    2015-01-01

    Objective: The primary objective of the study was to investigate the feasibility, reliability, and validity of the Dutch digits in noise (DIN) test for measuring speech recognition in hearing aid and cochlear implant users and compare results to the standard sentences-in-noise (SIN) test. Design:

  3. Underwater Vehicle

    National Research Council Canada - National Science Library

    Dick, James L

    2007-01-01

    There is thus provided an underwater vehicle having facility for maneuvering alongside a retrieving vehicle, as by manipulation of bow and stern planes, for engaging a hull surface of the retrieving...

  4. Learning to Learn: An Analysis of Early Learning Behaviours Demonstrated by Young Deaf/Hard-of-Hearing Children with High/Low Mathematics Ability

    Science.gov (United States)

    Pagliaro, Claudia M.; Kritzer, Karen L.

    2010-01-01

    Using a multiple case-study design, this study compares the early learning behaviours of young deaf/hard-of-hearing (d/hh) children with high/low mathematics ability (as defined by test score on the Test of Early Mathematics Ability-3). Children's simultaneous use of multiple learning behaviours was also examined as were contributing adult…

  5. Normal Hearing Ability but Impaired Auditory Selective Attention Associated with Prediction of Response to Donepezil in Patients with Alzheimer's Disease

    Science.gov (United States)

    Ouchi, Yoshitaka; Meguro, Kenichi; Akanuma, Kyoko; Kato, Yuriko; Yamaguchi, Satoshi

    2015-01-01

    Background. Alzheimer's disease (AD) patients have a poor response to the voices of caregivers. After administration of donepezil, caregivers often find that patients respond more frequently, whereas they had previously pretended to be “deaf.” We investigated whether auditory selective attention is associated with response to donepezil. Methods. The subjects were40 AD patients, 20 elderly healthy controls (HCs), and 15 young HCs. Pure tone audiometry was conducted and an original Auditory Selective Attention (ASA) test was performed with a MoCA vigilance test. Reassessment of the AD group was performed after donepezil treatment for 3 months. Results. Hearing level of the AD group was the same as that of the elderly HC group. However, ASA test scores decreased in the AD group and were correlated with the vigilance test scores. Donepezil responders (MMSE 3+) also showed improvement on the ASA test. At baseline, the responders had higher vigilance and lower ASA test scores. Conclusion. Contrary to the common view, AD patients had a similar level of hearing ability to healthy elderly. Auditory attention was impaired in AD patients, which suggests that unnecessary sounds should be avoided in nursing homes. Auditory selective attention is associated with response to donepezil in AD. PMID:26161001

  6. Lungfish Hearing

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Madsen, Peter Teglberg; Christensen-Dalsgaard, Jakob

    my after the first truly terrestrial tetrapods emerged. One of the major challenges is to understand the transitional stages from tetrapod ancestors to the tympanic tetrapod ear, for example how a non-tympanic ear functions in terrestrial hearing. Lungfish are the closest living relatives......Recent research has shown that tympanic middle ears evolved independently in the major vertebrate groups and represent independent experiments in terrestrial hearing. Furthermore, the tympanic ear emerged quite late – ap - proximately 120 mya after the origin of the tetrapods and approximately 70...... of the tetrapods, and the ear of lungfish may be similar to the ear of theearly tetrapods. We have studied the sensitivity of African lungfish to air-borne sound, underwater sound and vibrations. We show that lung - fish detect underwater sound pressure via pressure-to-par - ticle motion transduction by air...

  7. Improving speech-in-noise recognition for children with hearing loss: potential effects of language abilities, binaural summation, and head shadow.

    Science.gov (United States)

    Nittrouer, Susan; Caldwell-Tarr, Amanda; Tarr, Eric; Lowenstein, Joanna H; Rice, Caitlin; Moberly, Aaron C

    2013-08-01

    This study examined speech recognition in noise for children with hearing loss, compared it to recognition for children with normal hearing, and examined mechanisms that might explain variance in children's abilities to recognize speech in noise. Word recognition was measured in two levels of noise, both when the speech and noise were co-located in front and when the noise came separately from one side. Four mechanisms were examined as factors possibly explaining variance: vocabulary knowledge, sensitivity to phonological structure, binaural summation, and head shadow. Participants were 113 eight-year-old children. Forty-eight had normal hearing (NH) and 65 had hearing loss: 18 with hearing aids (HAs), 19 with one cochlear implant (CI), and 28 with two CIs. Phonological sensitivity explained a significant amount of between-groups variance in speech-in-noise recognition. Little evidence of binaural summation was found. Head shadow was similar in magnitude for children with NH and with CIs, regardless of whether they wore one or two CIs. Children with HAs showed reduced head shadow effects. These outcomes suggest that in order to improve speech-in-noise recognition for children with hearing loss, intervention needs to be comprehensive, focusing on both language abilities and auditory mechanisms.

  8. Relationship between swim bladder morphology and hearing abilities--a case study on Asian and African cichlids.

    Directory of Open Access Journals (Sweden)

    Tanja Schulz-Mirbach

    Full Text Available BACKGROUND: Several teleost species have evolved anterior extensions of the swim bladder which come close to or directly contact the inner ears. A few comparative studies have shown that these morphological specializations may enhance hearing abilities. This study investigates the diversity of swim bladder morphology in four Asian and African cichlid species and analyzes how this diversity affects their hearing sensitivity. METHODOLOGY/PRINCIPAL FINDINGS: We studied swim bladder morphology by dissections and by making 3D reconstructions from high-resolution microCT scans. The auditory sensitivity was determined in terms of sound pressure levels (SPL and particle acceleration levels (PAL using the auditory evoked potential (AEP recording technique. The swim bladders in Hemichromis guttatus and Steatocranus tinanti lacked anterior extensions and the swim bladder was considerably small in the latter species. In contrast, Paratilapia polleni and especially Etroplus maculatus possessed anterior extensions bringing the swim bladder close to the inner ears. All species were able to detect frequencies up to 3 kHz (SPL except S. tinanti which only responded to frequencies up to 0.7 kHz. P. polleni and E. maculatus showed significantly higher auditory sensitivities at 0.5 and 1 kHz than the two species lacking anterior swim bladder extensions. The highest auditory sensitivities were found in E. maculatus, which possessed the most intimate swim bladder-inner ear relationship (maximum sensitivity 66 dB re 1 µPa at 0.5 kHz. CONCLUSIONS: Our results indicate that anterior swim bladder extensions seem to improve mean absolute auditory sensitivities by 21-42 dB (SPLs and 21-36 dB (PALs between 0.5 and 1 kHz. Besides anterior extensions, the size of the swim bladder appears to be an important factor for extending the detectable frequency range (up to 3 kHz.

  9. The Speech Intelligibility Index and the Pure-Tone Average as Predictors of Lexical Ability in Children Fit with Hearing Aids

    Science.gov (United States)

    Stiles, Derek J.; Bentler, Ruth A.; McGregor, Karla K.

    2012-01-01

    Purpose: To determine whether a clinically obtainable measure of audibility, the aided Speech Intelligibility Index (SII; American National Standards Institute, 2007), is more sensitive than the pure-tone average (PTA) at predicting the lexical abilities of children who wear hearing aids (CHA). Method: School-age CHA and age-matched children with…

  10. Impacts of underwater noise on marine vertebrates

    NARCIS (Netherlands)

    Liebschner, Alexander; Seibel, Henrike; Teilmann, Jonas; Wittekind, Dietrich; Parmentier, Eric; Dähne, Michael; Dietz, Rune; Driver, Jörg; Elk, van Cornelis; Everaarts, Eligius; Findeisen, Henning; Kristensen, Jacob; Lehnert, Kristina; Lucke, Klaus; Merck, Thomas; Müller, Sabine; Pawliczka, Iwona; Ronnenberg, Katrin; Rosenberger, Tanja; Ruser, Andreas; Tougaard, Jakob; Schuster, Max; Sundermeyer, Janne; Sveegaard, Signe; Siebert, Ursula

    2016-01-01

    The project conducts application-oriented research on impacts of underwater noise on marine vertebrates in the North and Baltic Seas. In distinct subprojects, the hearing sensitivity of harbor porpoises and gray seals as well as the acoustic tolerance limit of harbor porpoises to impulsive noise

  11. Auditory Evoked Potentials for the Evaluation of Hearing Sensitivity in Navy Dolphins. Modification P00002: Assessment of Hearing Sensitivity in Adult Male Elephant Seals

    Science.gov (United States)

    2006-12-30

    is likely frequency dependent. electrical leakage to the water. Differences between the in-air The limitations in the jawphone calibration mean that...method provides noticeable gains given the vari- moto , M., Sato, 0., Suga, N., and Yanagisawa, K. (1968). "Electrophysi- ability inherent in evoked...underwater (seawater provides an alternative dress a need for periodic hearing assessment of dolphins at low resistance path for the electrical

  12. Underwater manipulator

    Science.gov (United States)

    Schrum, P.B.; Cohen, G.H.

    1993-04-20

    Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer [plus minus]45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer [plus minus]10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion.

  13. Underwater manipulator

    International Nuclear Information System (INIS)

    Schrum, P.B.; Cohen, G.H.

    1993-01-01

    Self-contained, waterproof, water-submersible, remote-controlled apparatus is described for manipulating a device, such as an ultrasonic transducer for measuring crack propagation on an underwater specimen undergoing shock testing. The subject manipulator includes metal bellows for transmittal of angular motions without the use of rotating shaft seals or O-rings. Inside the manipulator, a first stepper motor controls angular movement. In the preferred embodiment, the bellows permit the first stepper motor to move an ultrasonic transducer ±45 degrees in a first plane and a second bellows permit a second stepper motor to move the transducer ±10 degrees in a second plane orthogonal to the first. In addition, an XY motor-driven table provides XY motion

  14. Study of the Ability of Articulation Index (Al for Predicting the Unaided and Aided Speech Recognition Performance of 25 to 65 Years Old Hearing-Impaired Adults

    Directory of Open Access Journals (Sweden)

    Ghasem Mohammad Khani

    2001-05-01

    Full Text Available Background: In recent years there has been increased interest in the use of Al for assessing hearing handicap and for measuring the potential effectiveness of amplification system. AI is an expression of proportion of average speech signal that is audible to a given patient, and it can vary between 0.0 to 1.0. Method and Materials: This cross-sectional analytical study was carried out in department of audiology, rehabilitation, faculty, IUMS form 31 Oct 98 to 7 March 1999, on 40 normal hearing persons (80 ears; 19 males and 21 females and 40 hearing impaired persons (61 ears; 36 males and 25 females, 25-65 years old with moderate to moderately severe SNI-IL The pavlovic procedure (1988 for calculating Al, open set taped standard mono syllabic word lists, and the real -ear probe- tube microphone system to measure insertion gain were used, through test-retest. Results: 1/A significant correlation was shown between the Al scores and the speech recognition scores of normal hearing and hearing-impaired group with and without the hearing aid (P<0.05 2/ There was no significant differences in age group & sex: also 3 In test-retest measures of the insertion gain in each test and 4/No significant in test-retest of speech recognition test score. Conclusion: According to these results the Al can predict the unaided and aided monosyllabic recognition test scores very well, and age and sex variables have no effect on its ability. Therefore with respect to high reliability of the Al results and its simplicity, easy -to- use, cost effective, and little time consuming for calculation, its recommended the wide use of the Al, especially in clinical situation.

  15. EFFECTS ABILITIES MOTION IN SPACE OF CHILDREN WHO ARE DEAF OR HARD-OF-HEARING, WITHOUT USE OF EYESIGHT

    Directory of Open Access Journals (Sweden)

    Husnija Hasanbegović

    2014-09-01

    Full Text Available This study investigates knowledge on use of body extremities and body in space by children who are deaf or hard-of-hearing. A random sample of 60 participants was used in the study, with chronological age of 6 to 8 years. Experimental group of 30 participants involved pupils who are deaf or hard-of-hearing both male and female who attend school in Sarajevo (Bosnia and Herzegovina. Control group of 30 participants involved pupils who are typically hearing both male and female who were chronologically matched to the participants in the experimental group. Measuring instruments were created for the purpose of extracting quantitative data analysis, scaled from 1 to 5 units of measurement. The results are showed significant differences between children who are deaf or hard-of-hearing and children who are typically hearing (F=23, 08 p=0.00. The children who are deaf or hard-of-hearing showed significantly weaker knowledge of perception of body movements.

  16. Underwater Sound Reference Division

    Data.gov (United States)

    Federal Laboratory Consortium — The Underwater Sound Reference Division (USRD) serves as the U.S. standardizing activity in the area of underwater acoustic measurements, as the National Institute...

  17. EFFECTS ABILITIES MOTION IN SPACE OF CHILDREN WHO ARE DEAF OR HARD-OF-HEARING, WITHOUT USE OF EYESIGHT

    Directory of Open Access Journals (Sweden)

    Husnija Hasanbegović

    2014-09-01

    Full Text Available This study investigates knowledge on use of body extremities and body in space by children who are deaf or hard-ofhearing. A random sample of 60 participants was used in the study, with chronological age of 6 to 8 years. Experimental group of 30 participants involved pupils who are deaf or hard-of-hearing both male and female who attend school in Sarajevo (Bosnia and Herzegovina. Control group of 30 participants involved pupils who are typically hearing both male and female who were chronologically matched to the participants in the experimental group. Measuring instruments were created for the purpose of extracting quantitative data analysis, scaled from 1 to 5 units of measurement. The results are showed significant differences between children who are deaf or hard-of-hearing and children who are typically hearing (F=23, 08 p=0.00. The children who are deaf or hard-of-hearing showed significantly weaker knowledge of perception of body movements.

  18. A comparison of speech intonation production and perception abilities of Farsi speaking cochlear implanted and normal hearing children.

    Science.gov (United States)

    Moein, Narges; Khoddami, Seyyedeh Maryam; Shahbodaghi, Mohammad Rahim

    2017-10-01

    Cochlear implant prosthesis facilitates spoken language development and speech comprehension in children with severe-profound hearing loss. However, this prosthesis is limited in encoding information about fundamental frequency and pitch that are essentially for recognition of speech prosody. The purpose of the present study is to investigate the perception and production of intonation in cochlear implant children and comparison with normal hearing children. This study carried out on 25 cochlear implanted children and 50 children with normal hearing. First, using 10 action pictures statements and questions sentences were extracted. Fundamental frequency and pitch changes were identified using Praat software. Then, these sentences were judged by 7 adult listeners. In second stage 20 sentences were played for child and he/she determined whether it was in a question form or statement one. Performance of cochlear implanted children in perception and production of intonation was significantly lower than children with normal hearing. The difference between fundamental frequency and pitch changes in cochlear implanted children and children with normal hearing was significant (P speech and language pathologists should consider intervention of intonation in treatment program of cochlear implanted children. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Cortical and Sensory Causes of Individual Differences in Selective Attention Ability among Listeners with Normal Hearing Thresholds

    Science.gov (United States)

    Shinn-Cunningham, Barbara

    2017-01-01

    Purpose: This review provides clinicians with an overview of recent findings relevant to understanding why listeners with normal hearing thresholds (NHTs) sometimes suffer from communication difficulties in noisy settings. Method: The results from neuroscience and psychoacoustics are reviewed. Results: In noisy settings, listeners focus their…

  20. Semantic processing in deaf and hard-of-hearing children: Large N400 mismatch effects in brain responses, despite poor semantic ability

    Directory of Open Access Journals (Sweden)

    Petter Kallioinen

    2016-08-01

    Full Text Available Difficulties in auditory and phonological processing affect semantic processing in speech comprehension of deaf and hard-of-hearing (DHH children. However, little is known about brain responses of semantic processing in this group. We investigated event-related potentials (ERPs in DHH children with cochlear implants (CI and/or hearing aids (HA, and in normally hearing controls (NH. We used a semantic priming task with spoken word primes followed by picture targets. In both DHH children and controls, response differences between matching and mismatching targets revealed a typical N400-effect associated with semantic processing. Children with CI had the largest mismatch response despite poor semantic abilities overall, children with CI also had the largest ERP differentiation between mismatch types, with small effects of within-category mismatches (target from same category as prime and large effects between-category mismatches (were target is from a different category than prime. NH and HA children had similar responses to both mismatch types. While the large and differentiated ERP responses in the CI group were unexpected and should be interpreted with caution, the results could reflect less precision in semantic processing among children with CI, or a stronger reliance on predictive processing.

  1. Underwater Geotechnical Foundations

    National Research Council Canada - National Science Library

    Lee, Landris

    2001-01-01

    This report provides an overview and description of the design and construction of underwater geotechnical foundations and offers preliminary guidance based on past and current technology applications...

  2. Underwater gait analysis in Parkinson's disease.

    Science.gov (United States)

    Volpe, Daniele; Pavan, Davide; Morris, Meg; Guiotto, Annamaria; Iansek, Robert; Fortuna, Sofia; Frazzitta, Giuseppe; Sawacha, Zimi

    2017-02-01

    Although hydrotherapy is one of the physical therapies adopted to optimize gait rehabilitation in people with Parkinson disease, the quantitative measurement of gait-related outcomes has not been provided yet. This work aims to document the gait improvements in a group of parkinsonians after a hydrotherapy program through 2D and 3D underwater and on land gait analysis. Thirty-four parkinsonians and twenty-two controls were enrolled, divided into two different cohorts. In the first one, 2 groups of patients underwent underwater or land based walking training; controls underwent underwater walking training. Hence pre-treatment 2D underwater and on land gait analysis were performed, together with post-treatment on land gait analysis. Considering that current literature documented a reduced movement amplitude in parkinsonians across all lower limb joints in all movement planes, 3D underwater and on land gait analysis were performed on a second cohort of subjects (10 parkinsonians and 10 controls) who underwent underwater gait training. Baseline land 2D and 3D gait analysis in parkinsonians showed shorter stride length and slower speed than controls, in agreement with previous findings. Comparison between underwater and on land gait analysis showed reduction in stride length, cadence and speed on both parkinsonians and controls. Although patients who underwent underwater treatment exhibited significant changes on spatiotemporal parameters and sagittal plane lower limb kinematics, 3D gait analysis documented a significant (p<0.05) improvement in all movement planes. These data deserve attention for research directions promoting the optimal recovery and maintenance of walking ability. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  3. Habilidades pragmáticas em crianças deficientes auditivas: estudo de casos e controles Pragmatic abilities in hearing impaired children: a case-control study

    Directory of Open Access Journals (Sweden)

    Luana Curti

    2010-01-01

    Full Text Available OBJETIVO: Avaliar as habilidades pragmáticas de um grupo de crianças deficientes auditivas e compará-las a seus pares normo-ouvintes. MÉTODOS: Estudo de casos e controles composto por 32 crianças de ambos os gêneros com idades entre dois e seis anos. Dentre estas, 16 deficientes auditivas de grau moderadamente severo a profundo sem outros comprometimentos orgânicos (casos e 16 crianças normo-ouvintes sem queixas fonoaudiológicas (controle pareadas por idade. A avaliação e a análise da pragmática foram realizadas a partir do Teste ABFW-Pragmática, seguindo as instruções do protocolo. RESULTADOS: A média de idade das crianças estudadas foi quatro anos (DP=1,3; houve diferença significativa em relação ao número de atos comunicativos por minuto entre casos e controles (p=0,001. As crianças deficientes auditivas apresentaram menos iniciativas comunicativas do que as crianças normo-ouvintes e o meio comunicativo gestual foi utilizado por 13 (81, 3% destas e por cinco (32,2% das crianças normo-ouvintes (p=0,004. Não houve diferença entre os grupos em relação às intenções comunicativas (p=0,465. CONCLUSÃO: As crianças deficientes auditivas foram capazes de interagir em situações contextualizadas utilizando-se de funções comunicativas semelhantes às das ouvintes, e se diferiram destas quanto ao meio comunicativo mais utilizado.PURPOSE: To evaluate the pragmatic abilities of a group of hearing impaired children, and compare them with normal-listener peers. METHODS: Case-control study composed by 32 children of both genders with ages between two and six years, paired by age: 16 hearing impaired with moderately severe to profound hearing loss without other organic dysfunctions (cases, and 16 children with normal hearing with no Speech-Language Pathology complaints (control. The evaluation and analysis of pragmatic abilities were carried out based on the ABFW-Pragmatics Test, following instructions of its own protocol

  4. Underwater Scene Composition

    Science.gov (United States)

    Kim, Nanyoung

    2009-01-01

    In this article, the author describes an underwater scene composition for elementary-education majors. This project deals with watercolor with crayon or oil-pastel resist (medium); the beauty of nature represented by fish in the underwater scene (theme); texture and pattern (design elements); drawing simple forms (drawing skill); and composition…

  5. Effect of Workplace Noise on Hearing Ability in Tile and Ceramic Industry Workers in Iran: A 2-Year Follow-Up Study

    OpenAIRE

    Mostaghaci, Mehrdad; Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang; Bahaloo, Maryam; Mollasadeghi, Abolfazl; Davari, Mohammad Hossein

    2013-01-01

    Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. Methods. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according t...

  6. Underwater 3D filming

    Directory of Open Access Journals (Sweden)

    Roberto Rinaldi

    2014-12-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  7. Underwater Glider System Study

    OpenAIRE

    Jenkins, Scott A; Humphreys, Douglas E; Sherman, Jeff; Osse, Jim; Jones, Clayton; Leonard, Naomi; Graver, Joshua; Bachmayer, Ralf; Clem, Ted; Carroll, Paul; Davis, Philip; Berry, Jon; Worley, Paul; Wasyl, Joseph

    2003-01-01

    The goals of this study are to determine how to advance from present capabilities of underwater glider (and hybrid motorglider) technology to what could be possible within the next few years; and to identify critical research issues that must be resolved to make such advancements possible. These goals were pursued by merging archival flight data with numerical model results and system spreadsheet analysis to extrapolate from the present state-of-the–art in underwater (UW) gliders to potential...

  8. The effects of maternal stress and child language ability on behavioral outcomes of children with congenital hearing loss at 18-24months.

    Science.gov (United States)

    Topol, Deborah; Girard, Nicole; St Pierre, Lucille; Tucker, Richard; Vohr, Betty

    2011-12-01

    Prior studies have shown that children with congenital hearing loss have increased rates of behavior disorders. Child hearing loss has also been reported to be associated with increased maternal stress. Little is known about the behavior or the predictors of behavioral outcomes of children with hearing loss identified early and receiving Early Intervention services. The objective of this study was to identify the behavioral outcomes in early identified children with hearing loss and control hearing children at 18-24 months of age and to examine the impact of stress on early behavior development. It was hypothesized that children with hearing loss will have more behavior problems, and maternal stress will be associated with child behavior problems. Prospective observational. Children with and without congenital hearing loss and their mothers. The Parenting Stress Index and the Child Behavior Checklist. Children with hearing loss had increased scores for withdrawn and internalizing behavior. In multivariate analyses after adjusting for hearing loss, Neonatal Intensive Care Unit stay, and socioeconomic status, maternal stress independently contributed to higher scores for internalizing behavior, externalizing behavior, and total behavior problems. Maternal stress is an important correlate of behavior problems for children with hearing loss and should be considered by Early Intervention providers. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Effect of Workplace Noise on Hearing Ability in Tile and Ceramic Industry Workers in Iran: A 2-Year Follow-Up Study

    Directory of Open Access Journals (Sweden)

    Mehrdad Mostaghaci

    2013-01-01

    Full Text Available Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. Methods. This follow-up study was conducted on 555 workers (totally 1110 ears. Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear. Results. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%, 49 (8.83%, 22 (3.96%, and 63 (11.35% subjects in the first and second years of follow-up in the right and left ears, respectively. Conclusions. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices.

  10. Effect of workplace noise on hearing ability in tile and ceramic industry workers in Iran: a 2-year follow-up study.

    Science.gov (United States)

    Mostaghaci, Mehrdad; Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang; Bahaloo, Maryam; Mollasadeghi, Abolfazl; Davari, Mohammad Hossein

    2013-01-01

    Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%), 49 (8.83%), 22 (3.96%), and 63 (11.35%) subjects in the first and second years of follow-up in the right and left ears, respectively. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices.

  11. Strong tracking adaptive Kalman filters for underwater vehicle dead reckoning

    Science.gov (United States)

    Xiao, Kun; Fang, Shao-Ji; Pang, Yong-Jie

    2007-06-01

    To impove underwater vehicle dead reckoning, a developed strong tracking adaptive kalman filter is proposed. The filter is improved with an additional adaptive factor and an estimator of measurement noise covariance. Since the magnitude of fading factor is changed adaptively, the tracking ability of the filter is still enhanced in low velocity condition of underwater vehicles. The results of simulation tests prove the presented filter effective.

  12. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Conductive hearing loss (CHL) occurs because of a mechanical problem in the outer or middle ear. This may be ...

  13. Validation of the Hearing Implant Sound Quality Index (HISQUI19) to assess Spanish-speaking cochlear implant users' auditory abilities in everyday communication situations.

    Science.gov (United States)

    Calvino, Miryam; Gavilán, Javier; Sánchez-Cuadrado, Isabel; Pérez-Mora, Rosa M; Muñoz, Elena; Lassaletta, Luis

    2016-01-01

    The Spanish-language HISQUI19 is a reliable and easy-to-use tool for quantifying the self-perceived level of auditory benefit that cochlear implant (CI) users experience in everyday listening situations. To validate the Spanish-language version of The Hearing Implant Sound Quality Index (HISQUI19), a questionnaire for quantifying the self-perceived level of auditory benefit that CI users experience in everyday listening situations. Adult Spanish-speaking subjects with a CI were asked to complete a Spanish-language version of the HISQUI19. Reliability of the questionnaire was determined using Cronbach's α coefficient; exploratory factor analyses with a rotated (varimax) factor solution was applied to check construct validity; external validity was confirmed using Pearson's correlation. Test-re-test analysis was also performed. The MED-EL Assessment Database was used to assist in the administration, reporting, and data collection. Sixty-six of 77 subjects completed and returned the HISQUI19. The mean score auditory ability score (mean ± standard deviation) of the HISQUI19 was 79.9 ± 24.0, a 'moderate' auditory benefit. An inverse relationship was found between the HISQUI19 score and age at implantation. Gender and side of implantation did not influence self-perceived functioning. The objective measures (disyllables tested without lip-reading and in quiet) were correlated with the Total Score.

  14. Resources for Underwater Robotics Education

    Science.gov (United States)

    Wallace, Michael L.; Freitas, William M.

    2016-01-01

    4-H clubs can build and program underwater robots from raw materials. An annotated resource list for engaging youth in building underwater remotely operated vehicles (ROVs) is provided. This article is a companion piece to the Research in Brief article "Building Teen Futures with Underwater Robotics" in this issue of the "Journal of…

  15. Tribological properties of fish scale inspired underwater superoleophobic hierarchical structure in aqueous environment

    Science.gov (United States)

    Lian, Zhongxu; Xu, Jinkai; Wan, Yanling; Li, Yiquan; Yu, Zhanjiang; Liu, Qimeng; Yu, Huadong

    2017-10-01

    Underwater superoleophobic surfaces are becoming increasingly important in regard to self-cleaning, anti-fouling, oil droplet transportation and water/oil separation. Although a great number of underwater superoleophobic surfaces have been demonstrated, their tribological properties remain impractical for the purposes of real-life applications. Herein, a two-step method of high speed wire electrical discharge machining and boiling water treatment was adopted to fabricate fish scale inspired underwater oil repellent hierarchical structure on an aluminum (Al) alloy 5083 surface. The hierarchical roughness and hydroxyl groups were obtained on the surface, and the surface exhibited the ability to prevent contact with organic fluids when submerged in water. Moreover, the tribological properties of underwater superoleophobic Al surfaces in aqueous environments were analyzed. The average friction coefficient of underwater superoleophobic surfaces was decreased compared with the polished Al surface. We believe that this research will contribute to the engineering application of underwater superoleophobic surfaces in the future.

  16. Routing strategies for underwater gliders

    Science.gov (United States)

    Davis, Russ E.; Leonard, Naomi E.; Fratantoni, David M.

    2009-02-01

    Gliders are autonomous underwater vehicles that achieve long operating range by moving at speeds comparable to those of, or slower than, typical ocean currents. This paper addresses routing gliders to rapidly reach a specified waypoint or to maximize the ability to map a measured field, both in the presence of significant currents. For rapid transit in a frozen velocity field, direct minimization of travel time provides a trajectory "ray" equation. A simpler routing algorithm that requires less information is also discussed. Two approaches are developed to maximize the mapping ability, as measured by objective mapping error, of arrays of vehicles. In order to produce data sets that are readily interpretable, both approaches focus sampling near predetermined "ideal tracks" by measuring mapping skill only on those tracks, which are laid out with overall mapping skill in mind. One approach directly selects each vehicle's headings to maximize instantaneous mapping skill integrated over the entire array. Because mapping skill decreases when measurements are clustered, this method automatically coordinates glider arrays to maintain spacing. A simpler method that relies on manual control for array coordination employs a first-order control loop to balance staying close to the ideal track and maintaining vehicle speed to maximize mapping skill. While the various techniques discussed help in dealing with the slow speed of gliders, nothing can keep performance from being degraded when current speeds are comparable to vehicle speed. This suggests that glider utility could be greatly enhanced by the ability to operate high speeds for short periods when currents are strong.

  17. Hearing Loss in Children

    Science.gov (United States)

    ... services to help you and your child. Language: English (US) Español (Spanish) Recommend on Facebook Tweet Share Compartir Hearing loss can affect a child’s ability to develop communication, language, and social skills. The earlier children with hearing loss start getting ...

  18. Underwater laser detection system

    Science.gov (United States)

    Gomaa, Walid; El-Sherif, Ashraf F.; El-Sharkawy, Yasser H.

    2015-02-01

    The conventional method used to detect an underwater target is by sending and receiving some form of acoustic energy. But the acoustic systems have limitations in the range resolution and accuracy; while, the potential benefits of a laserbased underwater target detection include high directionality, high response, and high range accuracy. Lasers operating in the blue-green region of the light spectrum(420 : 570nm)have a several applications in the area of detection and ranging of submersible targets due to minimum attenuation through water ( less than 0.1 m-1) and maximum laser reflection from estimated target (like mines or submarines) to provide a long range of detection. In this paper laser attenuation in water was measured experimentally by new simple method by using high resolution spectrometer. The laser echoes from different targets (metal, plastic, wood, and rubber) were detected using high resolution CCD camera; the position of detection camera was optimized to provide a high reflection laser from target and low backscattering noise from the water medium, digital image processing techniques were applied to detect and discriminate the echoes from the metal target and subtract the echoes from other objects. Extraction the image of target from the scattering noise is done by background subtraction and edge detection techniques. As a conclusion, we present a high response laser imaging system to detect and discriminate small size, like-mine underwater targets.

  19. Underwater Gliders: A Review

    Directory of Open Access Journals (Sweden)

    Javaid Muhammad Yasar

    2014-07-01

    Full Text Available Underwater gliders are a type of underwater vehicle that transverse the oceans by shifting its buoyancy, during which its wings develop a component of the downward motion in the horizontal plane, thus producing a forward force. They are primarily used in oceanography sensing and data collection and play an important role in ocean research and development. Although there have been considerable developments in these gliders since the development of the first glider concept in 1989, to date, no review of these gliders have been done. This paper reviews existing underwater gliders, with emphasis on their respective working principles, range and payload capacity. All information on gliders available in the public domain or published in literature from the year 2000-2013 was reviewed. The majority of these gliders have an operational depth of 1000 m and a payload of less than 25 kg. The exception is a blend-body shape glider, which has a payload of approximately 800 kg and an operational depth around about 300 m. However, the commercialization of these gliders has been limited with only three know examples that have been successfully commercialized.

  20. Deep Learning Methods for Underwater Target Feature Extraction and Recognition

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-01-01

    Full Text Available The classification and recognition technology of underwater acoustic signal were always an important research content in the field of underwater acoustic signal processing. Currently, wavelet transform, Hilbert-Huang transform, and Mel frequency cepstral coefficients are used as a method of underwater acoustic signal feature extraction. In this paper, a method for feature extraction and identification of underwater noise data based on CNN and ELM is proposed. An automatic feature extraction method of underwater acoustic signals is proposed using depth convolution network. An underwater target recognition classifier is based on extreme learning machine. Although convolution neural networks can execute both feature extraction and classification, their function mainly relies on a full connection layer, which is trained by gradient descent-based; the generalization ability is limited and suboptimal, so an extreme learning machine (ELM was used in classification stage. Firstly, CNN learns deep and robust features, followed by the removing of the fully connected layers. Then ELM fed with the CNN features is used as the classifier to conduct an excellent classification. Experiments on the actual data set of civil ships obtained 93.04% recognition rate; compared to the traditional Mel frequency cepstral coefficients and Hilbert-Huang feature, recognition rate greatly improved.

  1. Development and validation of a questionnaire for hearing implant users to self-assess their auditory abilities in everyday communication situations: the Hearing Implant Sound Quality Index (HISQUI19).

    Science.gov (United States)

    Amann, Edda; Anderson, Ilona

    2014-09-01

    The Hearing Implant Sound Quality Index (HISQUI19) seems to be a valid tool for quantifying the self-perceived level of auditory benefit that cochlear implant (CI) users experience in everyday listening situations. Additional research is, however, required. To develop and validate a user-friendly instrument for quantifying the self-perceived level of auditory benefit that CI users experience in everyday listening situations. This was an explorative, uncontrolled, single-group, cross-sectional study. Items for the HISQUI19 were decided upon using user input and verified by professionals. The HISQUI19 was assessed on 75 CI users from hearing implant centres in Germany and Austria to determine the questions. The HISQUI19, consisting of 19 items scored on a 7-point Likert scale, was validated. Subjects older than 60 years at time of implantation did not have significantly higher mean values than subjects younger than 60 years. Gender and whether subjects are unilateral or bilateral implant CI users did not influence self-perceived functioning. Subjects with ≤20 years of hearing loss reported no significantly higher functioning than those with >20 years of hearing loss.

  2. Carbon Nanotube Underwater Acoustic Thermophone

    Science.gov (United States)

    2016-09-23

    Attorney Docket No. 300009 1 of 8 A CARBON NANOTUBE UNDERWATER ACOUSTIC THERMOPHONE STATEMENT OF GOVERNMENT INTEREST [0001] The...the Invention [0003] The present invention is an acoustically transparent carbon nanotube thermophone. (2) Description of the Prior Art [0004...amplitude of the resulting sound waves. [0006] Recently, there has been development of underwater acoustic carbon nanotube (CNT) yarn sheets capable

  3. Underwater gas tornado

    Science.gov (United States)

    Byalko, Alexey V.

    2013-07-01

    We present the first experimental observation of a new hydrodynamic phenomenon, the underwater tornado. Simple measurements show that the tornado forms a vortex of the Rankine type, i.e. the rising gas rotates as a solid body and the liquid rotates with a velocity decreasing hyperbolically with the radius. We obtain the dependence of the tornado radius a on the gas stream value j theoretically: a ∼ j2/5. Processing of a set of experiments yielded the value 0.36 for the exponent in this expression. We also report the initial stages of the theoretical study of this phenomenon.

  4. Genetics Home Reference: age-related hearing loss

    Science.gov (United States)

    ... Description Age-related hearing loss (also known as presbycusis) is a decrease in hearing ability that happens ... age-related old-aged sensorineural hearing impairment presbyacusia presbycusis Related Information How are genetic conditions and genes ...

  5. Numerical Estimation in Deaf and Hearing Adults

    Science.gov (United States)

    Bull, Rebecca; Marschark, Marc; Sapere, Patty; Davidson, Wendy A.; Murphy, Derek; Nordmann, Emily

    2011-01-01

    Deaf students often lag behind hearing peers in numerical and mathematical abilities. Studies of hearing children with mathematical difficulties highlight the importance of estimation skills as the foundation for formal mathematical abilities, but research with adults is limited. Deaf and hearing college students were assessed on the…

  6. Desempenho nas habilidades auditivas de atenção seletiva e memória auditiva em um grupo de idosos protetizados: influência de perda auditiva, idade e gênero Performance in the auditory abilities of selective attention and hearing memory in a group of elderly with hearing aids: Influence of hearing loss, age and gender

    Directory of Open Access Journals (Sweden)

    Leonardo Henrique Buss

    2012-01-01

    Full Text Available OBJETIVOS: verificar o desempenho nas habilidades auditivas de atenção seletiva e memória auditiva de idosos protetizados e relacioná-lo com o grau e configuração de perda auditiva, o gênero e a idade. MÉTODO: foram avaliados 29 idosos de 60 a 84 anos, sendo 17 (58,62% do gênero feminino e 12 (41,38% do gênero masculino. As avaliações realizadas incluíram meatoscopia, audiometria tonal liminar e aplicação do teste SSW em português. RESULTADOS: a análise dos dados permitiu verificar que, neste grupo de indivíduos, a idade e o grau de perda auditiva influenciaram significantemente nos escores obtidos na avaliação do processamento auditivo, diferentemente das demais variáveis. Os idosos que apresentaram perda auditiva de grau leve com configuração horizontal obtiveram escores significantemente superiores na avaliação do processamento auditivo comparados com os portadores de perda auditiva de grau moderado com configuração horizontal ou grau moderado com configuração descendente. Idosos pertencentes a faixa etária de 60-69 obtiveram desempenho superiormente significante comparado com idosos na faixa etária de 80-89 CONCLUSÃO: concluiu-se que o grau de perda auditiva e a idade influenciam nos resultados da avaliação do processamento auditivo. O gênero e a configuração de perda auditiva não foram fatores determinantes na avaliação do processamento auditivo.PURPOSE: to verify the performance in the auditory abilities of selective attention and hearing memory of elderly with prosthesis and relate it to the degree and the configuration of hearing loss, the gender and the age. METHOD: 29 elderly people from 60 to 84 years old were evaluated, 17 of them (58,62% females and 12 (41,38% males. The evaluations carried out included meatoscopy, audiometry evaluation and the use of the SSW test in Portuguese. RESULTS: the analysis of the data showed that, in this group of individuals, the age and the degree of auditory loss

  7. OFDM for underwater acoustic communications

    CERN Document Server

    Zhou, Shengli

    2014-01-01

    A blend of introductory material and advanced signal processing and communication techniques, of critical importance to underwater system and network development This book, which is the first to describe the processing techniques central to underwater OFDM, is arranged into four distinct sections: First, it describes the characteristics of underwater acoustic channels, and stresses the difference from wireless radio channels. Then it goes over the basics of OFDM and channel coding. The second part starts with an overview of the OFDM receiver, and develops various modules for the receiver des

  8. Development and experiments of the Sea-Wing underwater glider

    Science.gov (United States)

    Yu, Jian-Cheng; Zhang, Ai-Qun; Jin, Wen-Ming; Chen, Qi; Tian, Yu; Liu, Chong-Jie

    2011-12-01

    Underwater gliders, which glide through water columns by use of a pair of wings, are efficient long-distance, long-duration marine environment observatory platforms. The Sea-Wing underwater glider, developed by the Shenyang Institute of Automation, CAS, is designed for the application of deep-sea environment variables observation. The system components, the mechanical design, and the control system design of the Sea-Wing underwater glider are described in this paper. The pitch and roll adjusting models are derived based on the mechanical design, and the adjusting capabilities for the pitch and roll are analyzed according to the models. Field experiments have been carried out for validating the gliding motion and the ability of measuring ocean environment variables. Experimental results of the motion performances of the glider are presented.

  9. A Review of the Emerging Field of Underwater Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Emily Chua

    2016-11-01

    Full Text Available Mass spectrometers are versatile sensor systems, owing to their high sensitivity and ability to simultaneously measure multiple chemical species. Over the last two decades, traditional laboratory-based membrane inlet mass spectrometers have been adapted for underwater use. Underwater mass spectrometry has drastically improved our capability to monitor a broad suite of gaseous compounds (e.g., dissolved atmospheric gases, light hydrocarbons, and volatile organic compounds in the aquatic environment. Here we provide an overview of the progress made in the field of underwater mass spectrometry since its inception in the 1990s to the present. In particular, we discuss the approaches undertaken by various research groups in developing in situ mass spectrometers. We also provide examples to illustrate how underwater mass spectrometers have been used in the field. Finally, we present future trends in the field of in situ mass spectrometry. Most of these efforts are aimed at improving the quality and spatial and temporal scales of chemical measurements in the ocean. By providing up-to-date information on underwater mass spectrometry, this review offers guidance for researchers interested in adapting this technology as well as goals for future progress in the field.

  10. QFD-based conceptual design of an autonomous underwater robot

    Directory of Open Access Journals (Sweden)

    Thip Pasawang

    2015-12-01

    Full Text Available Autonomous underwater robots in the past few years have been designed according to the individual concepts and experiences of the researchers. To design a robot, which meets all the requirements of potential users, is an advanced work. Hence, a systematic design method that could include users’ preferences and requirements is needed. This paper presents the quality function deployment (QFD technique to design an autonomous underwater robot focusing on the Thai Navy military mission. Important user requirements extracted from the QFD method are the ability to record videos, operating at depth up to 10 meters, the ability to operate remotely with cable and safety concerns related to water leakages. Less important user requirements include beauty, using renewable energy, operating remotely with radio and ability to work during night time. The important design parameters derived from the user requirements are a low cost-controller, an autonomous control algorithm, a compass sensor and vertical gyroscope, and a depth sensor. Of low-importance ranked design parameters include the module design, use clean energy, a low noise electric motor, remote surveillance design, a pressure hull, and a beautiful hull form design. The study results show the feasibility of using QFD techniques to systematically design the autonomous underwater robot to meet user requirements. Mapping between the design and expected parameters and a conceptual drafting design of an autonomous underwater robot are also presented.

  11. Underwater plasma arc cutting

    International Nuclear Information System (INIS)

    Leautier, R.; Pilot, G.

    1991-01-01

    This report describes the work done to develop underwater plasma arc cutting techniques, to characterise aerosols from cutting operations on radioactive and non-radioactive work-pieces, and to develop suitable ventilation and filtration techniques. The work has been carried out in the framework of a contract between CEA-CEN Cadarache and the Commission of European Communities. Furthermore, this work has been carried out in close cooperation with CEA-CEN Saclay mainly for secondary emissions and radioactive analysis. The contract started in May 1986 and was completed in December 1988 by a supplementary agreement. This report has been compiled from several progress reports submitted during the work period, contains the main findings of the work and encloses the results of comparative tests on plasma arc cutting

  12. Safety aspects for underwater vehicles

    Digital Repository Service at National Institute of Oceanography (India)

    Madhan, R.; Navelkar, G.S.; Desa, E.S.; Afzulpurkar, S.; Prabhudesai, S.P.; Dabholkar, N.; Mascarenhas, A.A.M.Q.; Maurya, P.

    . This stresses for implementation of multiple safety measures of a high degree so that the platform operates continuously in a fail-safe mode. This paper discusses issues on safety measures implemented on the autonomous underwater platforms namely MAYA AUV...

  13. Underwater optical wireless communication network

    Science.gov (United States)

    Arnon, Shlomi

    2010-01-01

    The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  14. Hearing Screening

    Science.gov (United States)

    Johnson-Curiskis, Nanette

    2012-01-01

    Hearing levels are threatened by modern life--headsets for music, rock concerts, traffic noises, etc. It is crucial we know our hearing levels so that we can draw attention to potential problems. This exercise requires that students receive a hearing screening for their benefit as well as for making the connection of hearing to listening.

  15. An explanatory model of underwater adaptation

    Directory of Open Access Journals (Sweden)

    Joaquín Colodro

    Full Text Available The underwater environment is an extreme environment that requires a process of human adaptation with specific psychophysiological demands to ensure survival and productive activity. From the standpoint of existing models of intelligence, personality and performance, in this explanatory study we have analyzed the contribution of individual differences in explaining the adaptation of military personnel in a stressful environment. Structural equation analysis was employed to verify a model representing the direct effects of psychological variables on individual adaptation to an adverse environment, and we have been able to confirm, during basic military diving courses, the structural relationships among these variables and their ability to predict a third of the variance of a criterion that has been studied very little to date. In this way, we have confirmed in a sample of professionals (N = 575 the direct relationship of emotional adjustment, conscientiousness and general mental ability with underwater adaptation, as well as the inverse relationship of emotional reactivity. These constructs are the psychological basis for working under water, contributing to an improved adaptation to this environment and promoting risk prevention and safety in diving activities.

  16. Collective Modular Underwater Robotic System for Long-Term Autonomous Operation

    DEFF Research Database (Denmark)

    Christensen, David Johan; Andersen, Jens Christian; Blanke, Mogens

    This paper provides a brief overview of an underwater robotic system for autonomous inspection in confined offshore underwater structures. The system, which is currently in development, consist of heterogeneous modular robots able to physically dock and communicate with other robots, transport...... tools and robots, and recharge their batteries while underwater. These properties will provide the system, when fully developed, with unique capabilities such as ability to adapt robotic morphology and function to the current task and tolerate failures leading to long-term autonomous operations....

  17. Underwater cutting techniques developments

    International Nuclear Information System (INIS)

    Bach, F.-W.

    1990-01-01

    The primary circuit structures of different nuclear powerplants are constructed out of stainless steels, ferritic steels, plated ferritic steels and alloys of aluminium. According to the level of the specific radiation of these structures, it is necessary for dismantling to work with remote controlled cutting techniques. The most successful way to protect the working crew against exposure of radiation is to operate underwater in different depths. The following thermal cutting processes are more or less developed to work under water: For ferritic steels only - flame cutting; For ferritic steels, stainless steels, cladded steels and aluminium alloys - oxy-arc-cutting, arc-waterjet-cutting with a consumable electrode, arc-saw-cutting, plasma-arc-cutting and plasma-arc-saw. The flame cutting is a burning process, all the other processes are melt-cutting processes. This paper explains the different techniques, giving a short introduction of the theory, a discussion of the possibilities with the advantages and disadvantages of these processes giving a view into the further research work in this interesting field. (author)

  18. Current amplification models of sensorineurall and conductive hearing loss

    OpenAIRE

    Ostojić, Sanja; Mikić, Branka; Mirić, Danica

    2012-01-01

    The main function of a hearing aid is to improve auditory and language abilities of hearing impaired users. The amplification model has to be adapted according to age, degree and type of hearing loss. The goal of this paper is to analyze the current amplification models of sensorineural and conductive hearing loss which can provide a high quality of speech perception and sounds at any degree of hearing loss. The BAHA is a surgically implantable system for treatment of conductive hearing loss ...

  19. Modelling cavitating flow around underwater missiles

    Directory of Open Access Journals (Sweden)

    Fabien Petitpas

    2011-12-01

    Full Text Available The diffuse interface model of Saurel et al. (2008 is used for the computation of compressible cavitating flows around underwater missiles. Such systems use gas injection and natural cavitation to reduce drag effects. Consequently material interfaces appear separating liquid and gas. These interfaces may have a really complex dynamics such that only a few formulations are able to predict their evolution. Contrarily to front tracking or interface reconstruction method the interfaces are computed as diffused numerical zones, that are captured in a routinely manner, as is done usually with gas dynamics solvers for shocks and contact discontinuity. With the present approach, a single set of partial differential equations is solved everywhere, with a single numerical scheme. This leads to very efficient solvers. The algorithm derived in Saurel et al. (2009 is used to compute cavitation pockets around solid bodies. It is first validated against experiments done in cavitation tunnel at CNU. Then it is used to compute flows around high speed underwater systems (Shkval-like missile. Performance data are then computed showing method ability to predict forces acting on the system.

  20. Design of Autonomous Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Tadahiro Hyakudome

    2011-03-01

    Full Text Available There are concerns about the impact that global warming will have on our environment, and which will inevitably result in expanding deserts and rising water levels. While a lot of underwater vehicles are utilized, AUVs (Autonomous Underwater Vehicle were considered and chosen, as the most suitable tool for conduction survey concerning these global environmental problems. AUVs can comprehensive survey because the vehicle does not have to be connected to the support vessel by tether cable. When such underwater vehicles are made, it is necessary to consider about the following things. 1 Seawater and Water Pressure Environment, 2 Sink, 3 There are no Gas or Battery Charge Stations, 4 Global Positioning System cannot use, 5 Radio waves cannot use. In the paper, outline of above and how deal about it are explained.

  1. What do we need to hear a beat? The influence of attention, musical abilities, and accents on the perception of metrical rhythm

    NARCIS (Netherlands)

    Bouwer, F.L.

    2016-01-01

    In this dissertation, I examine beat perception, the process that allows us to make music together. I explore the effects of attention, musical abilities, and accents on beat perception. Additionally, I address several methodological issues that arise when probing beat perception with event-related

  2. About Hearing

    Science.gov (United States)

    ... th ) nerve, this is referred to as a " conductive hearing loss. " Common causes are excess wax in the outer ... or middle ear. Implications: When there is a " conductive hearing loss, " this typically causes sound to be muffled or ...

  3. Underwater laser imaging system (UWLIS)

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  4. Underwater measurements of muon intensity

    Science.gov (United States)

    Fedorov, V. M.; Pustovetov, V. P.; Trubkin, Y. A.; Kirilenkov, A. V.

    1985-01-01

    Experimental measurements of cosmic ray muon intensity deep underwater aimed at determining a muon absorption curve are of considerable interest, as they allow to reproduce independently the muon energy spectrum at sea level. The comparison of the muon absorption curve in sea water with that in rock makes it possible to determine muon energy losses caused by nuclear interactions. The data available on muon absorption in water and that in rock are not equivalent. Underground measurements are numerous and have been carried out down to the depth of approx. 15km w.e., whereas underwater muon intensity have been measured twice and only down to approx. 3km deep.

  5. Hearing Problems

    Science.gov (United States)

    ... of hearing loss is called OCCUPATIONAL. Self CarePrevent occupational hearing loss by wearing protective ear plugs or earmuffs. Once ... t be reversed. If you think you have occupational hearing loss, see your doctor. Start OverDiagnosisEarwax blockage, called CERUMINOSIS, ...

  6. Hearing Loss

    Science.gov (United States)

    ... use information from the test to fit your child with hearing aids. A hearing aid is a small electronic device that your baby wears in or behind the ear. It makes some sounds louder and helps your baby hear spoken words. ... VRA) . This test is used with children between 6 months and 2½ years old. It ...

  7. Captive Bottlenose Dolphins Do Discriminate Human-Made Sounds Both Underwater and in the Air

    Science.gov (United States)

    Lima, Alice; Sébilleau, Mélissa; Boye, Martin; Durand, Candice; Hausberger, Martine; Lemasson, Alban

    2018-01-01

    Bottlenose dolphins (Tursiops truncatus) spontaneously emit individual acoustic signals that identify them to group members. We tested whether these cetaceans could learn artificial individual sound cues played underwater and whether they would generalize this learning to airborne sounds. Dolphins are thought to perceive only underwater sounds and their training depends largely on visual signals. We investigated the behavioral responses of seven dolphins in a group to learned human-made individual sound cues, played underwater and in the air. Dolphins recognized their own sound cue after hearing it underwater as they immediately moved toward the source, whereas when it was airborne they gazed more at the source of their own sound cue but did not approach it. We hypothesize that they perhaps detected modifications of the sound induced by air or were confused by the novelty of the situation, but nevertheless recognized they were being “targeted.” They did not respond when hearing another group member’s cue in either situation. This study provides further evidence that dolphins respond to individual-specific sounds and that these marine mammals possess some capacity for processing airborne acoustic signals. PMID:29445350

  8. Hearing aids for mild to moderate hearing loss in adults.

    Science.gov (United States)

    Ferguson, Melanie A; Kitterick, Pádraig T; Chong, Lee Yee; Edmondson-Jones, Mark; Barker, Fiona; Hoare, Derek J

    2017-09-25

    The main clinical intervention for mild to moderate hearing loss is the provision of hearing aids. These are routinely offered and fitted to those who seek help for hearing difficulties. By amplifying and improving access to sounds, and speech sounds in particular, the aim of hearing aid use is to reduce the negative consequences of hearing loss and improve participation in everyday life. To evaluate the effects of hearing aids for mild to moderate hearing loss in adults. The Cochrane ENT Information Specialist searched the ENT Trials Register; the Cochrane Register of Studies Online; MEDLINE; PubMed; EMBASE; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 23 March 2017. Randomised controlled trials (RCTs) of hearing aids compared to a passive or active control in adults with mild to moderate hearing loss. We used the standard methodological procedures expected by Cochrane. The primary outcomes in this review were hearing-specific health-related quality of life and the adverse effect pain. Secondary outcomes were health-related quality of life, listening ability and the adverse effect noise-induced hearing loss. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics. We included five RCTs involving 825 participants. The studies were carried out in the USA and Europe, and were published between 1987 and 2017. Risk of bias across the studies varied. Most had low risk for selection, reporting and attrition bias, and a high risk for performance and detection bias because blinding was inadequate or absent.All participants had mild to moderate hearing loss. The average age across all five studies was between 69 and 83 years. The duration of the studies ranged between six weeks and six months.There was a large beneficial effect of hearing aids on hearing-specific health-related quality of life associated with participation in daily life as

  9. An Underwater Color Image Quality Evaluation Metric.

    Science.gov (United States)

    Yang, Miao; Sowmya, Arcot

    2015-12-01

    Quality evaluation of underwater images is a key goal of underwater video image retrieval and intelligent processing. To date, no metric has been proposed for underwater color image quality evaluation (UCIQE). The special absorption and scattering characteristics of the water medium do not allow direct application of natural color image quality metrics especially to different underwater environments. In this paper, subjective testing for underwater image quality has been organized. The statistical distribution of the underwater image pixels in the CIELab color space related to subjective evaluation indicates the sharpness and colorful factors correlate well with subjective image quality perception. Based on these, a new UCIQE metric, which is a linear combination of chroma, saturation, and contrast, is proposed to quantify the non-uniform color cast, blurring, and low-contrast that characterize underwater engineering and monitoring images. Experiments are conducted to illustrate the performance of the proposed UCIQE metric and its capability to measure the underwater image enhancement results. They show that the proposed metric has comparable performance to the leading natural color image quality metrics and the underwater grayscale image quality metrics available in the literature, and can predict with higher accuracy the relative amount of degradation with similar image content in underwater environments. Importantly, UCIQE is a simple and fast solution for real-time underwater video processing. The effectiveness of the presented measure is also demonstrated by subjective evaluation. The results show better correlation between the UCIQE and the subjective mean opinion score.

  10. Calibration of Underwater Sound Transducers

    OpenAIRE

    H.R.S. Sastry

    1983-01-01

    The techniques of calibration of underwater sound transducers for farfield, near-field and closed environment conditions are reviewed in this paper .The design of acoustic calibration tank is mentioned. The facilities available at Naval Physical & Oceanographic Laboratory, Cochin for calibration of transducers are also listed.

  11. Underwater nuclear power plant structure

    International Nuclear Information System (INIS)

    Severs, S.; Toll, H.V.

    1982-01-01

    A structure for an underwater nuclear power generating plant comprising a triangular platform formed of tubular leg and truss members upon which are attached one or more large spherical pressure vessels and one or more small cylindrical auxiliary pressure vessels. (author)

  12. Underwater Robots Surface in Utah

    Science.gov (United States)

    Hurd, Randy C.; Hacking, Kip S.; Damarjian, Jennifer L.; Wright, Geoffrey A.; Truscott, Tadd

    2015-01-01

    Underwater robots (or ROVs: Remotely Operated Vehicles as they are typically called in industry) have recently become a very popular instructional STEM activity. Nationally, ROVs have been used in science and technology classrooms for several years in cities such as Seattle, San Diego, Virginia Beach, and other coastal areas. In the past two…

  13. A Study of Relationship between the Acoustic Sensitivity of Vestibular System and the Ability to Trigger Sound-Evoked Muscle Reflex of the Middle Ear in Adults with Normal Hearing

    Directory of Open Access Journals (Sweden)

    S.F. Emami

    2014-07-01

    Full Text Available Introduction & Objective: The vestibular system is sound sensitive and the sensitivity is related to the saccule. The vestibular afferents are projected to the middle ear muscles (such as the stapedius. The goal of this research was studying the relationship between the vestibular hearing and the sound-evoked muscle reflex of the middle ear to 500 HZ. Materials & Methods: This study was a cross sectional-comparison done in audiology department of Sheikholreis C‍‍linic (Hamadan, Iran. The study groups consisted of thirty healthy people and thirty patients with benign paroxysmal positional vertigo. Inclusion criteria of the present study were to have normal hearing on pure tone audiometry, acoustic reflex, and speech discrimination scores. Based on ipsilateral acoustic reflex test at 500HZ, they were divided to normal and abnormal groups. Then they were evaluated by cervical vestibular evoked myogenic potentials (cVEMPs and finally classified in three groups (N Normal ear , (CVUA Contra lateral vertiginous ear with unaffected saccular sensitivity to sound,(IVA Ipsilateral vertiginous ear with affected saccular sensitivity to sound. Results: Thirty affected ears (IVA with decreased vestibular excitability as detected by ab-normal cVEMPs, revealed abnormal findings of acoustic reflex at 500HZ. Whereas, both un-affected (CVUA and normal ears (N had normal results. Multiple comparisons of mean values of cVEMPs (p13,n23 and acoustic reflex at500HZ among the three groups were sig-nificant. The correlation between acoustic reflex at 500HZ and p13 latencies was significant. The n23 latencies showed significant correlation with acoustic reflex at 500HZ. Conclusion: The vestibular sensitivity to sound retains the ability to trigger sound-evoked re-flex of the middle ear at 500 HZ. (Sci J Hamadan Univ Med Sci 2014; 21 (2:99-104

  14. Can audiometric results predict qualitative hearing improvements in bone-anchored hearing aid recipients?

    Science.gov (United States)

    McNeil, M L; Gulliver, M; Morris, D P; Makki, F M; Bance, M

    2014-01-01

    Patients receiving a bone-anchored hearing aid have well-documented improvements in their quality of life and audiometric performance. However, the relationship between audiometric measurements and subjective improvement is not well understood. Adult patients enrolled in the Nova Scotia bone-anchored hearing aid programme were identified. The pure tone average for fitting the sound-field threshold, as well as the better and worse hearing ear bone conduction and air conduction levels, were collected pre-operatively. Recipients were asked to complete the Speech, Spatial and Qualities of Hearing questionnaire; their partners were asked to complete a pre- and post-bone anchored hearing aid fitting Hearing Handicap Inventory for Adults questionnaire. Forty-eight patients who completed and returned the Speech, Spatial and Qualities of Hearing questionnaire had partners who completed the Hearing Handicap Inventory for Adults questionnaire. The results from the Speech, Spatial and Qualities of Hearing questionnaire correlated with the sound-field hearing threshold post-bone-anchored hearing aid fitting and the pure tone average of the better hearing ear bone conduction (total Speech, Spatial and Qualities of Hearing Scale to the pre-operative better hearing ear air curve (r = 0.3); worse hearing ear air curve (r = 0.27); post-operative, bone-anchored hearing aid-aided sound-field thresholds (r = 0.35)). An improvement in sound-field threshold correlated only with spatial abilities. In the Hearing Handicap Inventory for Adults questionnaire, there was no correlation between the subjective evaluation of each patient and their partner. The subjective impressions of hearing aid recipients with regards to speech reception and the spatial qualities of hearing correlate well with pre-operative audiometric results. However, the overall magnitude of sound-field improvement predicts an improvement of spatial perception, but not other aspects of hearing, resulting in hearing aid

  15. Conductive hearing loss and bone conduction devices: restored binaural hearing?

    Science.gov (United States)

    Agterberg, Martijn J H; Hol, Myrthe K S; Cremers, Cor W R J; Mylanus, Emmanuel A M; van Opstal, John; Snik, Ad F M

    2011-01-01

    An important aspect of binaural hearing is the proper detection of interaural sound level differences and interaural timing differences. Assessments of binaural hearing were made in patients with acquired unilateral conductive hearing loss (UCHL, n = 11) or congenital UCHL (n = 10) after unilateral application of a bone conduction device (BCD), and in patients with bilateral conductive or mixed hearing loss after bilateral BCD application. Benefit (bilateral versus unilateral listening) was assessed by measuring directional hearing, compensation of the acoustic head shadow, binaural summation and binaural squelch. Measurements were performed after an acclimatization time of at least 10 weeks. Unilateral BCD application was beneficial, but there was less benefit in the patients with congenital UCHL as compared to patients with acquired UCHL. In adults with bilateral hearing loss, bilateral BCD application was clearly beneficial as compared to unilateral BCD application. Binaural summation was present, but binaural squelch could not be proven. To explain the poor results in the patients with congenital UCHL, two factors seemed to be important. First, a critical period in the development of binaural hearing might affect the binaural hearing abilities. Second, crossover stimulation, referring to additional stimulation of the cochlea contralateral to the BCD side, might deteriorate binaural hearing in patients with UCHL. Copyright © 2011 S. Karger AG, Basel.

  16. Age-related hearing loss in sea lions and their scientists

    Science.gov (United States)

    Schusterman, Ronald J.; Southall, Brandon; Kastak, David; Reichmuth Kastak, Colleen

    2002-05-01

    Interest in the hearing capabilities of California sea lions (Zalophus californianus) was first stimulated by the echolocation hypothesis and more recently by rising concern about coastal noise pollution. During a series of audiometric tests, we measured the absolute hearing sensitivity of two sea lions and two of their human investigators. Aerial hearing curves for each subject were obtained with a go/no-go procedure and standard psychophysics. Additionally, underwater hearing curves were obtained for the sea lions using the same procedures. Underwater, the older sea lion (22-25 years of age) showed hearing losses relative to the younger sea lion (13-16 years) that ranged from 10 dB at lower frequencies to 50 dB near the upper frequency limit. The older sea lions' hearing losses in air were consistent with those measured underwater. The older human (69 years) tested also showed losses relative to the younger human (22 years). These differences ranged from 15 dB at lower frequencies up to 35 dB at the highest frequency tested. The results obtained in this study document age-related hearing losses in sea lions and humans. The findings are consistent with data on presbycusis in other mammalian species, showing that maximum hearing loss occurs at the highest frequencies.

  17. The cormorant ear – an adaptation to underwater hearing?

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Wahlberg, Magnus; Christensen-Dalsgaard, Jakob

    anatomy. Wild-caught fledglings were anesthetized and their auditory brainstem response (ABR) to clicks and tone bursts was measured, first in an anechoic box in air and then in a large water-filled tank with their head and neck submerged 10 cm below the surface. The overall shape of air audiograms...... piston, which is reminiscent of the turtle ear....

  18. Beaked and Baleen Whale Hearing: Modeling Responses to Underwater Noise

    Science.gov (United States)

    2009-06-01

    Ketten, D. R. 1994. The role of temporal bone imaging in cochlear implants. Curr. Opn. Otol. & HN Surg., Otology -Neurotology. 2 (5): 401-408... Otology and Laryngology. 107 (11): 1-16. Ketten, D. R. and D. Wartzok. 1990. Three-dimensional reconstructions of the dolphin cochlea. In

  19. Network Computing for Distributed Underwater Acoustic Sensors

    Science.gov (United States)

    2014-03-31

    Physical layer in UASNs Our main investigations are about underwater communications using acoustic waves. Elec- tromagnetic and optical waves do not...Shengli, Z., and Jun-Hong, C. (2008), Prospects and problems of wireless communication for underwater sensor networks, Wirel. Commun . Mob. Comput., 8(8... Wireless Communications , 9(9), 2934–2944. [21] Pompili, D. and Akyildiz, I. (2010), A multimedia cross-layer protocol for underwater acoustic sensor networks

  20. Cooperative OFDM underwater acoustic communications

    CERN Document Server

    Cheng, Xilin; Cheng, Xiang

    2016-01-01

    Following underwater acoustic channel modeling, this book investigates the relationship between coherence time and transmission distances. It considers the power allocation issues of two typical transmission scenarios, namely short-range transmission and medium-long range transmission. For the former scenario, an adaptive system is developed based on instantaneous channel state information. The primary focus is on cooperative dual-hop orthogonal frequency division multiplexing (OFDM). This book includes the decomposed fountain codes designed to enable reliable communications with higher energy efficiency. It covers the Doppler Effect, which improves packet transmission reliability for effective low-complexity mirror-mapping-based intercarrier interference cancellation schemes capable of suppressing the intercarrier interference power level. Designed for professionals and researchers in the field of underwater acoustic communications, this book is also suitable for advanced-level students in electrical enginee...

  1. International Conference on Underwater Environment

    CERN Document Server

    Jaulin, Luc; Creuze, Vincent; Debese, Nathalie; Quidu, Isabelle; Clement, Benoît; Billon-Coat, Annick

    2016-01-01

    This volume constitutes the results of the International Conference on Underwater Environment, MOQESM’14, held at “Le Quartz” Conference Center in Brest, France, on October 14-15, 2014, within the framework of the 9th Sea Tech Week, International Marine Science and Technology Event. The objective of MOQESM'14 was to bring together researchers from both academia and industry, interested in marine robotics and hydrography with application to the coastal environment mapping and underwater infrastructures surveys. The common thread of the conference is the combination of technical control, perception, and localization, typically used in robotics, with the methods of mapping and bathymetry. The papers presented in this book focus on two main topics. Firstly, coastal and infrastructure mapping is addressed, focusing not only on hydrographic systems, but also on positioning systems, bathymetry, and remote sensing. The proposed methods rely on acoustic sensors such as side scan sonars, multibeam echo sounders, ...

  2. Buying a Hearing Aid

    Science.gov (United States)

    ... other medical information about your ears and health. Conductive Hearing Loss: A hearing loss is conductive when there is ... be available for these and other forms of conductive hearing loss. Sensorineural Hearing Loss: A hearing loss is sensorineural ...

  3. Adaptive Processes in Hearing

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Christensen-Dalsgaard, Jakob; Tranebjærg, Lisbeth

    2018-01-01

    induced by hearing impairment and the compensation provided by hearing devices. These devices themselves are now able to adapt to the listener’s individual environment, attentional state, and behavior. These topics related to auditory adaptation, in the broad sense of the term, were central to the 6th......Our auditory environment is constantly changing and evolving over time, requiring us to rapidly adapt to a complex dynamic sensory input. This adaptive ability of our auditory system can be observed at different levels, from individual cell responses to complex neural mechanisms and behavior...... International Symposium on Auditory and Audiological Research held in Nyborg, Denmark, in August 2017. The symposium addressed adaptive processes in hearing from different angles, together with a wide variety of other auditory and audiological topics. The papers in this special issue result from some...

  4. Do Hearing Protectors Protect Hearing?

    Science.gov (United States)

    Groenewold, Matthew R.; Masterson, Elizabeth A.; Themann, Christa L.; Davis, Rickie R.

    2015-01-01

    Background We examined the association between self-reported hearing protection use at work and incidence of hearing shifts over a 5-year period. Methods Audiometric data from 19,911 workers were analyzed. Two hearing shift measures—OSHA standard threshold shift (OSTS) and high-frequency threshold shift (HFTS)—were used to identify incident shifts in hearing between workers’ 2005 and 2009 audiograms. Adjusted odds ratios were generated using multivariable logistic regression with multi-level modeling. Results The odds ratio for hearing shift for workers who reported never versus always wearing hearing protection was nonsignificant for OSTS (OR 1.23, 95% CI 0.92–1.64) and marginally significant for HFTS (OR 1.26, 95% CI 1.00–1.59). A significant linear trend towards increased risk of HFTS with decreased use of hearing protection was observed (P = 0.02). Conclusion The study raises concern about the effectiveness of hearing protection as a substitute for noise control to prevent noise-induced hearing loss in the workplace. Am. J. Ind. Med. 57:1001–1010, 2014. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:24700499

  5. Underwater Coatings for Contamination Control

    International Nuclear Information System (INIS)

    Julia L. Tripp; Kip Archibald; Ann-Marie Phillips; Joseph Campbell

    2004-01-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included (1) Test Area North (TAN-607) with epoxy painted concrete walls; (2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; (3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and (4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55 F to 80 F dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: (1) Be easy to apply; (2) Adhere well to the four surfaces of interest; (3) Not change or have a negative impact on water chemistry or clarity; (4) Not be hazardous in final applied form; and (5) Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates

  6. Hearing Aids

    Science.gov (United States)

    ... prefer the open-fit hearing aid because their perception of their voice does not sound “plugged up.” ... My voice sounds too loud. The “plugged-up” sensation that causes a hearing aid user’s voice to ...

  7. Identifying the barriers and facilitators to optimal hearing aid self-efficacy.

    Science.gov (United States)

    Meyer, Carly; Hickson, Louise; Fletcher, Amanda

    2014-02-01

    Many older adults with hearing impairment are not confident in their ability to use hearing aids (i.e. experience low hearing aid self-efficacy), which has been found to be a barrier to hearing help-seeking and hearing aid use. This study aimed to determine what factors were associated with achieving adequate hearing aid self-efficacy. A retrospective research design was employed wherein hearing aid self-efficacy was the primary outcome. Explanatory variables included personal demographics, visual disability, and experiences related to participants' hearing ability and hearing aids. A total of 307 older adults with hearing impairment participated in the study (147 non hearing aid owners and 160 hearing aid owners). Non-hearing aid owners were more likely to report adequate hearing aid self-efficacy if they reported no visual disability, had experienced hearing loss for longer, reported more positive support from a significant other, and were not anxious about wearing hearing aids. Hearing aid owners were more likely to report adequate hearing aid self-efficacy if they had had a positive hearing aid experience and no visual disability. More research is needed to develop and evaluate intervention approaches that promote optimal levels of hearing aid self-efficacy among older adults with hearing impairment.

  8. Adult hearing screening: the Cyprus Pilot Program

    Directory of Open Access Journals (Sweden)

    C. Thodi

    2011-03-01

    Full Text Available Hearing loss is the third most common condition affecting adults over 65 (Cruickshanks et al., 1998. It can affect quality of life, limiting the ability to communicate efficiently, and leading to isolation, psychological strain, and functional decline (LaForge, Spector, Sternberg, 1992; Yueh, Shapiro, MacLean, Shekelle, 2003. Communication limitations impinge on the person directly, as well as the family, friends, and social circle. Reports on hearing loss among adults indicate that less than 25% of people who can benefit from amplification are actually using hearing aids, and that people diagnosed with a hearing loss delay seeking amplification by about seven years (Kochkin, 1997. Often, family members are the driving force behind a person with a hearing loss who decides to seek help. Adult hearing screening programs might have a positive effect on raising public awareness on hearing loss and its implications, and shortening delay time for intervention. There is no routine hearing screening for the adult population in Cyprus. The health system provides hearing tests for beneficiaries upon physician recommendation or self-referral. The Cyprus pilot adult hearing screening program (ΑΠΑΣ- EVERYONE- Greek acronym for Screening- Intervention-Hearing-Participation to Life screened hearing in retired adults.

  9. Hearing Impairment

    Science.gov (United States)

    ... interpreted as sound. The cochlea is like a piano: specific areas along the length of the cochlea ... of permanent hearing loss and usually people can benefit from cochlear implants. In some other cases, the ...

  10. Model based image restoration for underwater images

    Science.gov (United States)

    Stephan, Thomas; Frühberger, Peter; Werling, Stefan; Heizmann, Michael

    2013-04-01

    The inspection of offshore parks, dam walls and other infrastructure under water is expensive and time consuming, because such constructions must be inspected manually by divers. Underwater buildings have to be examined visually to find small cracks, spallings or other deficiencies. Automation of underwater inspection depends on established water-proved imaging systems. Most underwater imaging systems are based on acoustic sensors (sonar). The disadvantage of such an acoustic system is the loss of the complete visual impression. All information embedded in texture and surface reflectance gets lost. Therefore acoustic sensors are mostly insufficient for these kind of visual inspection tasks. Imaging systems based on optical sensors feature an enormous potential for underwater applications. The bandwidth from visual imaging systems reach from inspection of underwater buildings via marine biological applications through to exploration of the seafloor. The reason for the lack of established optical systems for underwater inspection tasks lies in technical difficulties of underwater image acquisition and processing. Lightening, highly degraded images make a computational postprocessing absolutely essential.

  11. Relationship between hearing complaint and hearing loss among older people

    Directory of Open Access Journals (Sweden)

    Teixeira, Adriane Ribeiro

    2009-03-01

    Full Text Available Introduction: Presbycusis is a public health problem. Despite its high prevalence, many elders do not have their hearing ability investigated periodically, because they do not have a specific complaint. Objective: To check whether there is a relationship between the complaint and the presence of hearing loss in elder people. Method: Transversal study in elders from a neighborhood in the city of Canoas, Rio Grande do Sul. After the definition of the neighborhood's geographic boundaries, all houses were visited, the older people's addresses were ascertained and the invitations to take part in the research were provided. A questionnaire survey was applied which had a question about hearing loss complaint and air-conducted hearing thresholds were obtained and studied. Out of the 72 identified elders 50 elders agreed to participate, 35 (70% women, and 15 (30% men. Results: It was confirmed that only 12 (24% elders showed a specific complaint of hearing loss, although 33 (66% elders showed slight, moderate, severe and profound hearing losses. Conclusion: Data analysis confirmed there was no relationship between the complaint and the presence of hearing loss in the assessed group, and demonstrated the need to forward the elders for audiological evaluation even without any specific complaint.

  12. Does hearing aid use affect audiovisual integration in mild hearing impairment?

    Science.gov (United States)

    Gieseler, Anja; Tahden, Maike A S; Thiel, Christiane M; Colonius, Hans

    2018-02-16

    There is converging evidence for altered audiovisual integration abilities in hearing-impaired individuals and those with profound hearing loss who are provided with cochlear implants, compared to normal-hearing adults. Still, little is known on the effects of hearing aid use on audiovisual integration in mild hearing loss, although this constitutes one of the most prevalent conditions in the elderly and, yet, often remains untreated in its early stages. This study investigated differences in the strength of audiovisual integration between elderly hearing aid users and those with the same degree of mild hearing loss who were not using hearing aids, the non-users, by measuring their susceptibility to the sound-induced flash illusion. We also explored the corresponding window of integration by varying the stimulus onset asynchronies. To examine general group differences that are not attributable to specific hearing aid settings but rather reflect overall changes associated with habitual hearing aid use, the group of hearing aid users was tested unaided while individually controlling for audibility. We found greater audiovisual integration together with a wider window of integration in hearing aid users compared to their age-matched untreated peers. Signal detection analyses indicate that a change in perceptual sensitivity as well as in bias may underlie the observed effects. Our results and comparisons with other studies in normal-hearing older adults suggest that both mild hearing impairment and hearing aid use seem to affect audiovisual integration, possibly in the sense that hearing aid use may reverse the effects of hearing loss on audiovisual integration. We suggest that these findings may be particularly important for auditory rehabilitation and call for a longitudinal study.

  13. 4th Pacific Rim Underwater Acoustics Conference

    CERN Document Server

    Xu, Wen; Cheng, Qianliu; Zhao, Hangfang

    2016-01-01

    These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

  14. A new technique for robot vision in autonomous underwater vehicles using the color shift in underwater imaging

    Science.gov (United States)

    2017-06-01

    FOR ROBOT VISION IN AUTONOMOUS UNDERWATER VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING by Jake A. Jones June 2017 Thesis Advisor... VEHICLES USING THE COLOR SHIFT IN UNDERWATER IMAGING 5. FUNDING NUMBERS 6. AUTHOR(S) Jake A. Jones 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS...underwater vehicles (AUVs), robot vision, autonomy, visual odometry, underwater color shift, optical properties of water 15. NUMBER OF PAGES 75 16

  15. Robotics Vision-based Heuristic Reasoning for Underwater Target Tracking and Navigation

    Directory of Open Access Journals (Sweden)

    Chua Kia

    2008-11-01

    Full Text Available This paper presents a robotics vision-based heuristic reasoning system for underwater target tracking and navigation. This system is introduced to improve the level of automation of underwater Remote Operated Vehicles (ROVs operations. A prototype which combines computer vision with an underwater robotics system is successfully designed and developed to perform target tracking and intelligent navigation. This study focuses on developing image processing algorithms and fuzzy inference system for the analysis of the terrain. The vision system developed is capable of interpreting underwater scene by extracting subjective uncertainties of the object of interest. Subjective uncertainties are further processed as multiple inputs of a fuzzy inference system that is capable of making crisp decisions concerning where to navigate. The important part of the image analysis is morphological filtering. The applications focus on binary images with the extension of gray-level concepts. An open-loop fuzzy control system is developed for classifying the traverse of terrain. The great achievement is the system's capability to recognize and perform target tracking of the object of interest (pipeline in perspective view based on perceived condition. The effectiveness of this approach is demonstrated by computer and prototype simulations. This work is originated from the desire to develop robotics vision system with the ability to mimic the human expert's judgement and reasoning when maneuvering ROV in the traverse of the underwater terrain.

  16. Jellyfish inspired underwater unmanned vehicle

    Science.gov (United States)

    Villanueva, Alex; Bresser, Scott; Chung, Sanghun; Tadesse, Yonas; Priya, Shashank

    2009-03-01

    An unmanned underwater vehicle (UUV) was designed inspired by the form and functionality of a Jellyfish. These natural organisms were chosen as bio-inspiration for a multitude of reasons including: efficiency of locomotion, lack of natural predators, proper form and shape to incorporate payload, and varying range of sizes. The structure consists of a hub body surrounded by bell segments and microcontroller based drive system. The locomotion of UUV was achieved by shape memory alloy "Biometal Fiber" actuation which possesses large strain and blocking force with adequate response time. The main criterion in design of UUV was the use of low-profile shape memory alloy actuators which act as artificial muscles. In this manuscript, we discuss the design of two Jellyfish prototypes and present experimental results illustrating the performance and power consumption.

  17. Underwater sympathetic detonation of pellet explosive

    Science.gov (United States)

    Kubota, Shiro; Saburi, Tei; Nagayama, Kunihito

    2017-06-01

    The underwater sympathetic detonation of pellet explosives was taken by high-speed photography. The diameter and the thickness of the pellet were 20 and 10 mm, respectively. The experimental system consists of the precise electric detonator, two grams of composition C4 booster and three pellets, and these were set in water tank. High-speed video camera, HPV-X made by Shimadzu was used with 10 Mfs. The underwater explosions of the precise electric detonator, the C4 booster and a pellet were also taken by high-speed photography to estimate the propagation processes of the underwater shock waves. Numerical simulation of the underwater sympathetic detonation of the pellet explosives was also carried out and compared with experiment.

  18. Underwater Grass Comeback Helps Chesapeake Bay

    Science.gov (United States)

    The fortified Susquehanna Flats, the largest bed of underwater grasses in the Chesapeake Bay, seems able to withstand a major weather punch. Its resilience is contributing to an overall increase in the Bay’s submerged aquatic vegetation.

  19. Underwater Object Segmentation Based on Optical Features

    Directory of Open Access Journals (Sweden)

    Zhe Chen

    2018-01-01

    Full Text Available Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object of interest, and, therefore, we can initially identify the region of target objects if the collimation of artificial light is recognized. Based on this concept, we propose an optical feature extraction, calculation, and decision method to identify the collimated region of artificial light as a candidate object region. Then, the second phase employs a level set method to segment the objects of interest within the candidate region. This two-phase structure largely removes background noise and highlights the outline of underwater objects. We test the performance of the method with diverse underwater datasets, demonstrating that it outperforms previous methods.

  20. Sensor network architectures for monitoring underwater pipelines.

    Science.gov (United States)

    Mohamed, Nader; Jawhar, Imad; Al-Jaroodi, Jameela; Zhang, Liren

    2011-01-01

    This paper develops and compares different sensor network architecture designs that can be used for monitoring underwater pipeline infrastructures. These architectures are underwater wired sensor networks, underwater acoustic wireless sensor networks, RF (radio frequency) wireless sensor networks, integrated wired/acoustic wireless sensor networks, and integrated wired/RF wireless sensor networks. The paper also discusses the reliability challenges and enhancement approaches for these network architectures. The reliability evaluation, characteristics, advantages, and disadvantages among these architectures are discussed and compared. Three reliability factors are used for the discussion and comparison: the network connectivity, the continuity of power supply for the network, and the physical network security. In addition, the paper also develops and evaluates a hierarchical sensor network framework for underwater pipeline monitoring.

  1. Underwater photogrammetry successful in Spain and France

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    Underwater photogrammetry has been used to measure distortions in fuel assembly alignment pins in the upper internals of the Almarez and Dampierre PWRs. Photogrammetry is a three-dimensional precision measurement method using photographic techniques for the on-site measurement phase. On the strength of the operations at the two PWRs, underwater photogrammetry is now considered as a practical and effective technique for dimensional inspection at nuclear plants. (U.K.)

  2. Underwater noise levels in UK waters

    OpenAIRE

    Merchant, Nathan D.; Brookes, Kate L.; Faulkner, Rebecca C.; Bicknell, Anthony W. J.; Godley, Brendan J.; Witt, Matthew J.

    2016-01-01

    Underwater noise from human activities appears to be rising, with ramifications for acoustically sensitive marine organisms and the functioning of marine ecosystems. Policymakers are beginning to address the risk of ecological impact, but are constrained by a lack of data on current and historic noise levels. Here, we present the first nationally coordinated effort to quantify underwater noise levels, in support of UK policy objectives under the EU Marine Strategy Framework Directive (MSFD). ...

  3. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  4. An underwater optical wireless communication network

    Science.gov (United States)

    Arnon, Shlomi

    2009-08-01

    The growing need for underwater observation and sub-sea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, bio-geochemical, evolutionary and ecological changes in the sea, ocean and lake environments and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. We present models of three kinds of optical wireless communication links a) a line-of-sight link, b) a modulating retro-reflector link and c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered lighted it was possible to mitigate this decrease in some cases. We conclude from the analysis that a high data rate underwater optical wireless network is a feasible solution for emerging applications such as UUV to UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  5. HEARING LOSS, ITS IMPLICATIONS AND PUBLIC HEALTH INTERVENTIONS

    OpenAIRE

    Suneela; Kalika

    2015-01-01

    Globally, over 5% of world’s population (More than 360 million population), have disabling hearing loss according to new global estimates on prevalence; 91% of these are adults and 9% of these are children. Overall, prevalence of disabling hearing loss in children all over the world is 1.7%.1 Prevalence of hearing loss in South Asia in pediatric age group is 2.4%. Consequences of hearing impairment include inability to interpret speech sounds, often producing a reduced ability to ...

  6. Verbal and Spatial Analogical Reasoning in Deaf and Hearing Children: The Role of Grammar and Vocabulary

    Science.gov (United States)

    Edwards, Lindsey; Figueras, Berta; Mellanby, Jane; Langdon, Dawn

    2011-01-01

    The extent to which cognitive development and abilities are dependent on language remains controversial. In this study, the analogical reasoning skills of deaf and hard of hearing children are explored. Two groups of children (deaf and hard of hearing children with either cochlear implants or hearing aids and hearing children) completed tests of…

  7. Hearing Loss

    Science.gov (United States)

    ... law Sound level, decibels Duration, daily BASED ON OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION, 2008 90 8 hours 92 6 hours 95 4 hours 97 3 hours 100 2 hours 102 1.5 hours 105 1 hour 110 30 minutes 115 15 minutes or less Complications Hearing loss can have a significant effect on your quality ...

  8. Design and implementation of omni-directional light source and receiving system used in underwater wireless optical communication

    Science.gov (United States)

    Rao, Jionghui; Yao, Wenming; Chen, Nannan

    2013-08-01

    Underwater wireless optical communication is a communication mode which uses light as an information carrier and water as transmission medium. As a result of the inherent characteristics of the light waves, underwater wireless optical communication has the advantages of high transmission rate, good security, and strong anti-interference ability. It is suitable for high-speed, short-range communication between underwater mobile vehicles. Underwater optical wireless communication system designed in this paper is composed of the omni-directional communication light source and the receiving system. In the omni-directional communication light source, the laser beams with small divergence angle of 532nm wavelength produced by modulated laser are expanded through a combination refraction-reflection solid and then obtain more than 2π space divergence angle. The paper use TRACEPRO simulation tool to help design a combination solid composed of the lens, conical reflector and parabolic reflector, and test in the air and underwater, the result shows that the effect is fine. Unlike in the air, light attenuation is heavy in the water and a large range of variations in light intensity at different distances appear during underwater optical communication. In order to overcome this problem, the paper use a small photomultiplier as the detection device, design the receiving system using the automatic gain control technique. Underwater wireless optical communication system designed in this paper has the characteristics of small size, low power dissipation and the omni-directional communication function, it is suitable for application in the UUV, AUV, Swimmer Delivery Vehicle (SDV) and other underwater mobile platform, it realizes point-to-point communications and point-to-multipoint communications.

  9. Underwater Noise Modeling in Lithuanian Area of the Baltic Sea

    Directory of Open Access Journals (Sweden)

    Donatas Bagočius

    2017-09-01

    Full Text Available Along with rising awareness of public and scientific societies about environmental and ecological impacts of underwater noise, the need for underwater noise modelling in the shallow Lithuanian area of Baltic Sea emerged. Marine Strategy Framework Directive issues regarding underwater noise indicators refers to possibility of evaluation of Good Environmental State using underwater noise measurements as well as possibility to model underwater noise. Main anthropogenic underwater noise contributor in the Seas is the shipping lanes as known due to date, with no exclusion of Lithuanian Baltic Sea area. In this manuscript, it is presented the methods of development of simplistic underwater ambient noise model purposed for computation of underwater soundscape in shallow area of the Lithuanian Baltic Sea.

  10. Underwater Sensor Networks: A New Energy Efficient and Robust Architecture

    NARCIS (Netherlands)

    Climent, Salvador; Capella, Juan Vincente; Meratnia, Nirvana; Serrano, Juan José

    2012-01-01

    The specific characteristics of underwater environments introduce new challenges for networking protocols. In this paper, a specialized architecture for underwater sensor networks (UWSNs) is proposed and evaluated. Experiments are conducted in order to analyze the suitability of this protocol for

  11. Hearing Loss in Children: Types of Hearing Loss

    Science.gov (United States)

    ... hearing. There are four types of hearing loss: Conductive Hearing Loss Hearing loss caused by something that stops sounds ... Hearing Loss Hearing loss that includes both a conductive and a sensorineural hearing loss. Auditory Neuropathy Spectrum Disorder Hearing loss that occurs ...

  12. Magnetohydrodynamic underwater vehicular propulsion systems

    International Nuclear Information System (INIS)

    Swallom, D.W.; Sadovnik, I.; Gibbs, J.S.; Gurol, H.; Nguyen, L.

    1990-01-01

    The development of magnetohydrodynamic propulsion systems for underwater vehicles is discussed. According to the authors, it is a high risk endeavor that offers the possibility of a number of significant advantages over conventional propeller propulsion systems. These advantages may include the potential for greater stealth characteristics, increased maneuverability, enhanced survivability, elimination of cavitation limits, and addition of a significant emergency propulsion system. The possibility of increased stealth is by far the most important advantage. A conceptual design study has been completed with numerical results that shows that these advantages may be obtained with a magnetohydrodynamic propulsion system in an annular configuration externally surrounding a generic study submarine that is neutrally buoyant and can operate with the existing submarine propulsion system power plant. The classical submarine mission requirements make the use of these characteristics of the magnetohydrodynamic propulsion system particularly appropriate for submarine missions. The magnetohydrodynamic annular propulsion system for a generic attack class submarine has been designed to take advantage of the magnetohydrodynamic thruster characteristics

  13. Health-related quality of life in adults with hearing impairment before and after hearing-aid rehabilitation in Finland.

    Science.gov (United States)

    Niemensivu, Riina; Manchaiah, Vinaya; Roine, Risto P; Kentala, Erna; Sintonen, Harri

    2015-01-01

    The aim of this study was to evaluate health-related quality of life (HRQoL) in adults with hearing impairment in Finland before and after hearing rehabilitation. The study was prospective with hearing-aid rehabilitation as the intervention. The data was collected, using the 15D instrument, before and six months after hearing-aid rehabilitation. The data was analysed using t-tests and multiple linear regression methods. The study sample included 949 adults with hearing impairment, and the control group included a sample of age- and gender-standardized general population. The study population had significantly poorer HRQoL on most dimensions of the 15D when compared to the control group both before and after hearing-aid rehabilitation. Hearing-aid rehabilitation resulted in improved mean scores on the dimensions of hearing and in the overall 15D score that were statistically significant, although the mean improvement in the overall score was marginal. Self-reported hearing ability can better predict the change in HRQoL, as a result of a hearing aid, when compared with measured hearing sensitivity. The study supports the hypothesis that on average, use of a unilateral hearing aid results in improved subjective hearing and marginal improvement in HRQoL in adults with hearing impairment.

  14. What is important for hearing aid satisfaction? Application of the expectancy-disconfirmation model.

    Science.gov (United States)

    Meyer, Carly; Hickson, Louise; Khan, Asad; Walker, David

    2014-01-01

    Between 68.1-89.5% of clients report that they are satisfied with their hearing aids. Two variables that are thought to contribute to dissatisfaction with hearing aids are product performance, and a mismatch between performance and client prefitting expectations about hearing-aid performance (i.e., disconfirmation). A focus on variables related to satisfaction is relevant to improving hearing rehabilitation services. The aim of this study was to determine if measures of hearing-aid performance and disconfirmation, specifically related to hearing ability and hearing-aid problems, were associated with overall hearing-aid satisfaction among a sample of hearing-aid users. A retrospective research design was employed. A total of 123 individuals participated in the study (57% male; mean age: 72 yr). All participants owned hearing aids. A personal details questionnaire and the Profile of Hearing Aid Consumer Satisfaction questionnaire (Wong et al, 2009) were completed by participants, 3-12 mo after they obtained hearing aids. Overall hearing-aid satisfaction was a dichotomized variable (satisfaction vs. dissatisfaction); therefore, logistic regression modeling was applied to the data to determine which variables were associated with overall hearing-aid satisfaction. Sixty-one percent of the sample reported that they were satisfied with their hearing aids. Hearing-aid satisfaction was associated with the ability to hear with hearing aids and better-than-expected performance in this same area; fewer hearing-aid problems; and fewer problems with hearing-aid manipulation, hearing-aid appearance, and wearer discomfort than were anticipated before hearing-aid fitting. It is recommended that to improve hearing-aid satisfaction, clinicians should ensure optimal hearing-aid benefit in the listening situations that the person with hearing impairment most wants to hear better; reduce the likelihood of hearing-aid problems occurring; and promote positive disconfirmation (performance

  15. Measurements on Hearing

    DEFF Research Database (Denmark)

    Poulsen, Torben

    1996-01-01

    Background material for measurements of hearing for grammar school pupils. The note gives the necessary background for the exercise 'Measurement on Hearing'. The topics comprise sound and decibel, the ear, basic psychoacoustics, hearing threshold, audiometric measurement methods, speech and speech...

  16. OI Issues: Hearing Loss

    Science.gov (United States)

    ... loss can occur at any age, including childhood. Conductive Hearing Loss : Usually results from a physical problem in the ... This type of test can determine if the hearing loss is conductive or sensorineural. Adults who have an identified hearing ...

  17. Satisfaction of Elderly Hearing Aid Users

    Science.gov (United States)

    Kozlowski, Lorena; Ribas, Angela; Almeida, Gleide; Luz, Idalina

    2016-01-01

    Introduction The impact of auditory sensory deprivation in the life of an individual is enormous because it not only affects one's ability to properly understand auditory information, but also the way people relate to their environment and their culture. The monitoring of adult and elderly subjects with hearing loss is intended to minimize the difficulties and handicaps that occur as a consequence of this pathology. Objective To evaluate the level of user satisfaction with hearing aids. Methods A clinical and experimental study involving 91 elderly hearing aid users. We used the questionnaire Satisfaction with Amplification in Daily Life to determine the degree of the satisfaction provided by hearing aids. We evaluated mean global score, subscales, as well as the variables time to use, age, and degree of hearing loss. Results Mean global score was 4.73, the score for Positive Effects 5.45, Negative Factors 3.2, demonstrating that they were satisfied; Services and Costs 5.98: very satisfied ; 3.65 Personal Image: dissatisfied. We observed statistically significant difference for the time of hearing aid use, age, and degree of hearing loss. Conclusion The SADL is a tool, simple and easy to apply and in this study we can demonstrate the high degree of satisfaction with the hearing aids by the majority of the sample collected, increasing with time of use and a greater degree of hearing loss. PMID:28050214

  18. How to Get Hearing Aids

    Science.gov (United States)

    ... Consumer Products Hearing Aids How to get Hearing Aids Share Tweet Linkedin Pin it More sharing options ... my hearing aids? How do I get hearing aids? Before getting a hearing aid, you should consider ...

  19. Survivability design for a hybrid underwater vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong [State Key Lab of Ocean Engineering, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-03-10

    A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system.

  20. Survivability design for a hybrid underwater vehicle

    International Nuclear Information System (INIS)

    Wang, Biao; Wu, Chao; Li, Xiang; Zhao, Qingkai; Ge, Tong

    2015-01-01

    A novel hybrid underwater robotic vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes: operate as an untethered autonomous vehicle in autonomous underwater vehicle (AUV) mode and operate under remote control connected to the surface vessel by a lightweight, fiber optic tether in remotely operated vehicle (ROV) mode. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes, survivability has been placed on an equal level with the other design attributes of the HROV since the beginning of the project. This paper reports the survivability design elements for the HROV including basic vehicle design of integrated navigation and integrated communication, emergency recovery strategy, distributed architecture, redundant bus, dual battery package, emergency jettison system and self-repairing control system

  1. Recent developments in underwater repair welding

    International Nuclear Information System (INIS)

    Offer, H.P.; Chapman, T.L.; Willis, E.R.; Maslakowski, J.; Van Diemen, P.; Smith, B.W.

    2001-01-01

    As nuclear plants age and reactor internal components begin to show increased evidence of age-related phenomena such as corrosion and fatigue, interest in the development of cost-effective mitigation and repair remedies grows. One technology currently receiving greater development and application program focus is underwater welding. Underwater welding, as used herein, is the application of weld metal to a substrate surface that is wet, but locally dry in the immediate area surrounding the welding torch. The locally dry environment is achieved by the use of a mechanical device that is specifically designed for water exclusion from the welding torch, surface to be welded, and the welding groove. This paper will explore recent developments in the use of underwater welding as a mitigation and repair technique. (author)

  2. Long-term results of hearing preservation cochlear implant surgery in patients with residual low frequency hearing.

    Science.gov (United States)

    Moteki, Hideaki; Nishio, Shin-Ya; Miyagawa, Maiko; Tsukada, Keita; Iwasaki, Satoshi; Usami, Shin-Ichi

    2017-05-01

    Differences were found between patients with stable hearing and those with progressive hearing loss in the lower frequencies with respect to the rate of progression in the contralateral ear. It is suggested that the electric acoustic stimulation (EAS) can provide improvement in hearing ability over the long-term if residual hearing might be lost to some extent. To evaluate the long-term threshold changes in the low frequency hearing of the implanted ear as compared with the non-implanted ear, and the hearing abilities with EAS along with the extent of residual hearing. Seventeen individuals were enrolled and received the EAS implant with a 24-mm FLEXeas electrode array. Hearing thresholds and speech perception were measured pre- and post-operatively for 1-5 years. Post-operative hearing preservation (HP) rates were calculated using the preservation numerical scale. The average linear regression coefficient for the decline in hearing preservation score was -6.9 for the implanted ear and the patients were subsequently categorized into two groups: those with better than average, stable hearing; and those with worse than average, progressive hearing loss. EAS showed better results than electric stimulation alone, in spite of an absence of speech perception with acoustic stimulation.

  3. Efficient Modelling Methodology for Reconfigurable Underwater Robots

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Cornelius; Blanke, Mogens; Schjølberg, Ingrid

    2016-01-01

    This paper considers the challenge of applying reconfigurable robots in an underwater environment. The main result presented is the development of a model for a system comprised of N, possibly heterogeneous, robots dynamically connected to each other and moving with 6 Degrees of Freedom (DOF......). This paper presents an application of the Udwadia-Kalaba Equation for modelling the Reconfigurable Underwater Robots. The constraints developed to enforce the rigid connection between robots in the system is derived through restrictions on relative distances and orientations. To avoid singularities...... in the orientation and, thereby, allow the robots to undertake any relative configuration the attitude is represented in Euler parameters....

  4. Underwater laser cutting of metallic structures

    International Nuclear Information System (INIS)

    Alfille, J.P.; Schildknecht, J.; Ramaswami, V.S.

    1993-01-01

    In the frame of an european contract, the feasibility of the underwater cutting with a CO 2 laser power is studied. The aim of this work is the dismantling metallic structures of reactors pools. The paper analyzes the general concept of the experimental device, the underwater cutting head, the experimenting vessel, examples of cuttings in dismantling situation with a 500 W CO 2 laser, and examples of cuttings with a 5 kW CO 2 laser. (author). 2 refs., 9 figs., 2 tabs

  5. Underwater noise from offshore oil production vessels.

    Science.gov (United States)

    Erbe, Christine; McCauley, Robert; McPherson, Craig; Gavrilov, Alexander

    2013-06-01

    Underwater acoustic recordings of six Floating Production Storage and Offloading (FPSO) vessels moored off Western Australia are presented. Monopole source spectra were computed for use in environmental impact assessments of underwater noise. Given that operations on the FPSOs varied over the period of recording, and were sometimes unknown, the authors present a statistical approach to noise level estimation. No significant or consistent aspect dependence was found for the six FPSOs. Noise levels did not scale with FPSO size or power. The 5th, 50th (median), and 95th percentile source levels (broadband, 20 to 2500 Hz) were 188, 181, and 173 dB re 1 μPa @ 1 m, respectively.

  6. The Effects of Hearing Aids on Localization of White Noise by Blind Subjects.

    Science.gov (United States)

    Bergen, Bruce R.

    1980-01-01

    An investigation was conducted to observe the effects of hearing aids on the ability of 20 blind veterans to localize white noise. In all cases, Ss performed more poorly on a localization task while wearing a hearing aid. (Author)

  7. Dismantling of JPDR reactor internals by underwater plasma arc cutting technique using robotic manipulator

    International Nuclear Information System (INIS)

    Yokota, M.

    1988-01-01

    The actual dismantling of JPDR started on December 4, 1986. As of now, equipment that surrounds the reactor has mostly been removed to provide working space in reactor containment prior to the dismantling of reactor internals. Some reactor internals have been successfully dismantled using the underwater arc cutting system with a robotic manipulator during the period of January to March 1988. The cutting system is composed of an underwater plasma arc cutting device and a robotic manipulator. The cut off reactor internals were core spray block, feedwater sparger and stabilizers for fuel upper grid tube. The plasma arc cutting device was developed to dismantle the reactor internals underwater. It mainly consists of a plasma torch, power and gas supply systems for the torch, and by-product treatment systems. It has the cutting ability of 130 mm thickness stainless steel underwater. The robotic manipulator has seven degrees of freedom of movement, enabling it to move in almost the same way as the arm of a human being. The arm of the robot is mounted on a supporting device which is suspended by three chains from the support structure set on a service floor. A plasma torch is griped by the robotic hand; its position to the structure to be cut is controlled from a remote control room, about 100 meters outside the reactor containment

  8. Femtosecond laser fabrication of robust underwater superoleophobic and anti-oil surface on sapphire

    Science.gov (United States)

    Chu, Dongkai; Yin, Kai; Dong, Xinran; Luo, Zhi; Duan, Ji-An

    2017-11-01

    Due to the presence of unique micro/nanostructures on the surface, fish's scale exhibits underwater superoleophobicity and keeps clean even in oil-polluted water. Inspired from this, we propose a facile method for the fabrication of underwater superoleophobic and anti-oil sapphire surface with line-patterned nanostructures by femtosecond laser. The as-prepared surface shows great superoleophobicity that the oil contact angles can reach up to 153° for 1, 2-dichloroethane droplets in water and low oil-adhesion. At the same time, the relationship between the microgrooves' period and surface wettability is studied, and the results indicate that the underwater superoleophobicity and low oil-adhesion can be achieved using a wide range of processing parameters. Meanwhile, the obtained surface is demonstrated to exhibit excellent stability. Moreover, the self-cleaning anti-oil ability of the as-prepared surface is conducted, and the potential mechanism of which is discussed. This technique has potential applications for the fabrication of underwater oil repelling devices and microfluidics.

  9. DOA Estimation for Underwater Wideband Weak Targets Based on Coherent Signal Subspace and Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Jun Li

    2018-03-01

    Full Text Available Direction of arrival (DOA estimation is the basis for underwater target localization and tracking using towed line array sonar devices. A method of DOA estimation for underwater wideband weak targets based on coherent signal subspace (CSS processing and compressed sensing (CS theory is proposed. Under the CSS processing framework, wideband frequency focusing is accompanied by a two-sided correlation transformation, allowing the DOA of underwater wideband targets to be estimated based on the spatial sparsity of the targets and the compressed sensing reconstruction algorithm. Through analysis and processing of simulation data and marine trial data, it is shown that this method can accomplish the DOA estimation of underwater wideband weak targets. Results also show that this method can considerably improve the spatial spectrum of weak target signals, enhancing the ability to detect them. It can solve the problems of low directional resolution and unreliable weak-target detection in traditional beamforming technology. Compared with the conventional minimum variance distortionless response beamformers (MVDR, this method has many advantages, such as higher directional resolution, wider detection range, fewer required snapshots and more accurate detection for weak targets.

  10. Spreadsheet decision support model for MK 16 underwater breathing apparatus repair parts inventory management

    OpenAIRE

    Butler, Peter B.

    1994-01-01

    This thesis proposes a spreadsheet-based decision support model for determining the most effective repair parts inventory for the MK 16 Underwater Breathing Apparatus (MK 16). Incorporating U.S. Navy demand information, the model provides the inventory manager the ability to modify repair parts inventories as changes occur to the order and shipping times, tempo of operations, or the number of MK 16 assigned. The thesis explores the current methods of MK 16 repair parts inventory design and re...

  11. IVO develops a new repair technique for underwater sites. Viscous doughlike substance underwater cracks

    Energy Technology Data Exchange (ETDEWEB)

    Klingstedt, G.; Leisio, C. [ed.

    1998-07-01

    A viscous sealant is revolutionizing repair of the stone and concrete masonry of underwater dams, bridges and canals. There is now no need for expensive and time-consuming cofferdams, since a diver can extrude quick-setting mortar into underwater structures needing repair. This technique has worked well in recent years in various parts of Finland even in strongly flowing water. IVO experts are now starting to look more beyond the borders of Finland

  12. Hearing and hearing conservation practices among Australia′s professional orchestral musicians

    Directory of Open Access Journals (Sweden)

    Ian O′Brien

    2014-01-01

    Full Text Available Orchestral musicians are an at-risk population for noise-induced hearing loss. Following strategic approaches to mitigate exposure, many must use earplugs to safeguard their hearing, although reported usage rates are poor. Australia has progressive hearing conservation programs within many of its orchestras, yet little is known of earplug usage rates, abilities with earplugs or self-perceived hearing loss in this population. To help direct and inform future approaches to hearing conservation in Australia′s orchestras a questionnaire assessing hearing conservation behaviors and the prevalence of self-perceived hearing loss was distributed. A total of 580 musicians across eight professional orchestras were surveyed, with 367 completed surveys (63% returned. Eighty percent of respondents reported a risk of hearing damage in the orchestra, 64% used earplugs of some type at least some of the time and 83% found this use difficult/impossible. Forty-three percent reported a hearing loss, including 54% in pit orchestras and 46% of those ≤50 years of age. Brass players were least likely to use earplugs, most likely to report usage difficulties and most likely of those ≤50 years of age to report a hearing loss. While earplug usage rates in Australia are encouraging and may be linked to hearing conservation measures in the orchestras, the widespread difficulty reported with the use of these earplugs, the prevalence of self-reported hearing loss and the continued vulnerability of those most at-risk indicate improvements in both earplug design and further education for musicians are required to progress hearing conservation options for this population.

  13. Underwater Advanced Time-Domain Electromagnetic System

    Science.gov (United States)

    2017-03-03

    sufficiently waterproofed ...................................................................... 20 Objective: Calibration method can be used both topside... additional background variability is observed at early times, as illustrated in Figure 15. The layout of this figure is the same as Figure 14. Now the...are discussed in the following sections and summarized in Table 5. Objective: System is sufficiently waterproofed The array remained underwater up to

  14. Underwater Adhesives Retrofit Pipelines with Advanced Sensors

    Science.gov (United States)

    2015-01-01

    Houston-based Astro Technology Inc. used a partnership with Johnson Space Center to pioneer an advanced fiber-optic monitoring system for offshore oil pipelines. The company's underwater adhesives allow it to retrofit older deepwater systems in order to measure pressure, temperature, strain, and flow properties, giving energy companies crucial data in real time and significantly decreasing the risk of a catastrophe.

  15. Detection of Underwater UXOs in Mud

    Science.gov (United States)

    2013-04-01

    2nd International Conference on Underwater Acoustic Measurements, Crete, Greece, 2007. 16 [10] P.T. Gough and D.W. Hawkins “Imaging algorithms...course. Runs 275 and 325 folla.v the same trad < and run 322 foUows a track on the opposite side of the swath. The LF SAS image of run 325 is shown

  16. Adaptive turbo equalization for underwater acoustic communication

    NARCIS (Netherlands)

    Cannelli, L; Leus, G.; Dol, H.S.; Walree, P.A. van

    2013-01-01

    In this paper a multiband transceiver designed for underwater channels is presented. Multi-branch filtering at the receiver is used to leverage the diversity offered by a multi-scale multi-lag scenario. The multi-branch bank of filters is constructed by estimating scale and delay coefficients

  17. Underwater noise generated by offshore pile driving

    NARCIS (Netherlands)

    Tsouvalas, A.

    2015-01-01

    Anthropogenic noise emission in the marine environment has always been an environmental issue of serious concern. In particular, the noise generated during the installation of foundation piles is considered to be one of the most significant sources of underwater noise pollution. This is mainly

  18. Can Baby Hear?

    Science.gov (United States)

    ... born in the United States are deaf or hard-of-hearing. Research shows that early intervention with hearing devices and educational services can help children with hearing loss to develop language skills at the same rate as their hearing peers. ...

  19. Measuring Levels of Stress and Depression in Mothers of Children Using Hearing Aids and Cochlear Implants: A Comparative Study

    Science.gov (United States)

    Prakash, Santhi S; Prakash, S. G. R.; Ravichandran, Aparna; Susan, K. Y.; Alex, Winnie

    2013-01-01

    Hearing impairment is an exceptional circumstance that restricts the child's ability to communicate verbally. Depression is a common stress-related response for hearing parents of children with hearing loss. Evidence suggests that mothers are more inclined than fathers to experience depression in response to their child's hearing loss (Mavrolas,…

  20. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But prevention is possible and effective: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  1. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss ? do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but prevention is possible. For example, hearing protection devices can prevent 80% of tinnitus cases.

  2. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But PREVENTION IS POSSIBLE AND EFFECTIVE: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  3. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but PREVENTION IS POSSIBLE. For example, hearing protection devices can prevent 80% of tinnitus cases.

  4. The Master Hearing Aid

    Science.gov (United States)

    Curran, James R.

    2013-01-01

    As early as the 1930s the term Master Hearing Aid (MHA) described a device used in the fitting of hearing aids. In their original form, the MHA was a desktop system that allowed for simulated or actual adjustment of hearing aid components that resulted in a changed hearing aid response. Over the years the MHA saw many embodiments and contributed to a number of rationales for the fitting of hearing aids. During these same years, the MHA was viewed by many as an inappropriate means of demonstrating hearing aids; the audio quality of the desktop systems was often superior to the hearing aids themselves. These opinions and the evolution of the MHA have molded the modern perception of hearing aids and the techniques used in the fitting of hearing aids. This article reports on a history of the MHA and its influence on the fitting of hearing aids. PMID:23686682

  5. Enabling Persistent Autonomy for Underwater Gliders with Ocean Model Predictions and Terrain Based Navigation

    Directory of Open Access Journals (Sweden)

    Andrew eStuntz

    2016-04-01

    Full Text Available Effective study of ocean processes requires sampling over the duration of long (weeks to months oscillation patterns. Such sampling requires persistent, autonomous underwater vehicles, that have a similarly long deployment duration. The spatiotemporal dynamics of the ocean environment, coupled with limited communication capabilities, make navigation and localization difficult, especially in coastal regions where the majority of interesting phenomena occur. In this paper, we consider the combination of two methods for reducing navigation and localization error; a predictive approach based on ocean model predictions and a prior information approach derived from terrain-based navigation. The motivation for this work is not only for real-time state estimation, but also for accurately reconstructing the actual path that the vehicle traversed to contextualize the gathered data, with respect to the science question at hand. We present an application for the practical use of priors and predictions for large-scale ocean sampling. This combined approach builds upon previous works by the authors, and accurately localizes the traversed path of an underwater glider over long-duration, ocean deployments. The proposed method takes advantage of the reliable, short-term predictions of an ocean model, and the utility of priors used in terrain-based navigation over areas of significant bathymetric relief to bound uncertainty error in dead-reckoning navigation. This method improves upon our previously published works by 1 demonstrating the utility of our terrain-based navigation method with multiple field trials, and 2 presenting a hybrid algorithm that combines both approaches to bound navigational error and uncertainty for long-term deployments of underwater vehicles. We demonstrate the approach by examining data from actual field trials with autonomous underwater gliders, and demonstrate an ability to estimate geographical location of an underwater glider to 2

  6. Verbal and spatial analogical reasoning in deaf and hearing children: the role of grammar and vocabulary.

    Science.gov (United States)

    Edwards, Lindsey; Figueras, Berta; Mellanby, Jane; Langdon, Dawn

    2011-01-01

    The extent to which cognitive development and abilities are dependent on language remains controversial. In this study, the analogical reasoning skills of deaf and hard of hearing children are explored. Two groups of children (deaf and hard of hearing children with either cochlear implants or hearing aids and hearing children) completed tests of verbal and spatial analogical reasoning. Their vocabulary and grammar skills were also assessed to provide a measure of language attainment. Results indicated significant differences between the deaf and hard of hearing children (regardless of type of hearing device) and their hearing peers on vocabulary, grammar, and verbal reasoning tests. Regression analyses revealed that in the group of deaf and hard of hearing children, but not in the hearing group, the language measures were significant predictors of verbal analogical reasoning, when age and spatial analogical reasoning ability were controlled for. The implications of these findings are discussed.

  7. Stability analysis of hybrid-driven underwater glider

    Science.gov (United States)

    Niu, Wen-dong; Wang, Shu-xin; Wang, Yan-hui; Song, Yang; Zhu, Ya-qiang

    2017-10-01

    Hybrid-driven underwater glider is a new type of unmanned underwater vehicle, which combines the advantages of autonomous underwater vehicles and traditional underwater gliders. The autonomous underwater vehicles have good maneuverability and can travel with a high speed, while the traditional underwater gliders are highlighted by low power consumption, long voyage, long endurance and good stealth characteristics. The hybrid-driven underwater gliders can realize variable motion profiles by their own buoyancy-driven and propeller propulsion systems. Stability of the mechanical system determines the performance of the system. In this paper, the Petrel-II hybrid-driven underwater glider developed by Tianjin University is selected as the research object and the stability of hybrid-driven underwater glider unitedly controlled by buoyancy and propeller has been targeted and evidenced. The dimensionless equations of the hybrid-driven underwater glider are obtained when the propeller is working. Then, the steady speed and steady glide path angle under steady-state motion have also been achieved. The steady-state operating conditions can be calculated when the hybrid-driven underwater glider reaches the desired steady-state motion. And the steadystate operating conditions are relatively conservative at the lower bound of the velocity range compared with the range of the velocity derived from the method of the composite Lyapunov function. By calculating the hydrodynamic coefficients of the Petrel-II hybrid-driven underwater glider, the simulation analysis has been conducted. In addition, the results of the field trials conducted in the South China Sea and the Danjiangkou Reservoir of China have been presented to illustrate the validity of the analysis and simulation, and to show the feasibility of the method of the composite Lyapunov function which verifies the stability of the Petrel-II hybrid-driven underwater glider.

  8. Novel-word learning in children with normal hearing and hearing loss.

    Science.gov (United States)

    Stelmachowicz, Patricia G; Pittman, Andrea L; Hoover, Brenda M; Lewis, Dawna E

    2004-02-01

    The goal of this study was to assess performance on a novel-word learning task by normal-hearing and hearing-impaired children for words varying in form (noun versus verb), stimulus level (50 versus 60 dB SPL), and number of repetitions (4 versus 6). It was hypothesized that novel-word learning would be significantly poorer in the subjects with hearing loss, would increase with both level and repetition, and would be better for nouns than verbs. Twenty normal-hearing and 11 hearing-impaired children (6 to 9 yr old) participated in this study. Each child viewed a 4-minute animated slide show containing 8 novel words. The effects of hearing status, word form, repetition, and stimulus level were examined systematically. The influence of audibility, word recognition, chronological age, and lexical development also were evaluated. After hearing the story twice, children were asked to identify each word from a set of four pictures. Overall performance was 60% for the normal-hearing children and 41% for the children with hearing loss. Significant predictors of performance were PPVT raw scores, hearing status, stimulus level, and repetitions. The variables age, audibility, word recognition scores, and word form were not significant predictors. Results suggest that a child's ability to learn new words can be predicted from vocabulary size, stimulus level, number of exposures, and hearing status. Further, the sensitivity to presentation level observed in this novel-word learning task suggests that this type of paradigm may be an effective tool for studying various forms of hearing aid signal processing algorithms.

  9. Underwater videography and photography in Gulf of Kachchh. Sponsored by Gujarat Ecological Society, Vadodara, Gujarat

    Digital Repository Service at National Institute of Oceanography (India)

    Marine Archaeology Centre (MAC) has been carrying out underwater explorations and excavations of ancient ports and sunken shipwrecks to preserve underwater cultural heritage. MAC has the infrastructure facility to carry out underwater investigations...

  10. Hydrodynamic Coefficients Identification and Experimental Investigation for an Underwater Vehicle

    Directory of Open Access Journals (Sweden)

    Shaorong XIE

    2014-02-01

    Full Text Available Hydrodynamic coefficients are the foundation of unmanned underwater vehicles modeling and controller design. In order to reduce identification complexity and acquire necessary hydrodynamic coefficients for controllers design, the motion of the unmanned underwater vehicle was separated into vertical motion and horizontal motion models. Hydrodynamic coefficients were regarded as mapping parameters from input forces and moments to output velocities and acceleration of the unmanned underwater vehicle. The motion models of the unmanned underwater vehicle were nonlinear and Genetic Algorithm was adopted to identify those hydrodynamic coefficients. To verify the identification quality, velocities and acceleration of the unmanned underwater vehicle was measured using inertial sensor under the same conditions as Genetic Algorithm identification. Curves similarity between measured velocities and acceleration and those identified by Genetic Algorithm were used as optimizing standard. It is found that the curves similarity were high and identified hydrodynamic coefficients of the unmanned underwater vehicle satisfied the measured motion states well.

  11. Delay Tolerance in Underwater Wireless Communications: A Routing Perspective

    Directory of Open Access Journals (Sweden)

    Safdar Hussain Bouk

    2016-01-01

    Full Text Available Similar to terrestrial networks, underwater wireless networks (UWNs also aid several critical tasks including coastal surveillance, underwater pollution detection, and other maritime applications. Currently, once underwater sensor nodes are deployed at different levels of the sea, it is nearly impossible or very expensive to reconfigure the hardware, for example, battery. Taking this issue into account, considerable amount of research has been carried out to ensure minimum energy costs and reliable communication between underwater nodes and base stations. As a result, several different network protocols were proposed for UWN, including MAC, PHY, transport, and routing. Recently, a new paradigm was introduced claiming that the intermittent nature of acoustic channel and signal resulted in designing delay tolerant routing schemes for the UWN, known as an underwater delay tolerant network. In this paper, we provide a comprehensive survey of underwater routing protocols with emphasis on the limitations, challenges, and future open issues in the context of delay tolerant network routing.

  12. Acoustically Induced Streaming Flows near a Model Cod Otolith and their Potential Implications for Fish Hearing

    Energy Technology Data Exchange (ETDEWEB)

    Kotas, Charlotte W [ORNL; Rogers, Peter [Georgia Institute of Technology; Yoda, Minami [Georgia Institute of Technology

    2011-01-01

    The ears of fishes are remarkable sensors for the small acoustic disturbances associated with underwater sound. For example, each ear of the Atlantic cod (Gadus morhua) has three dense bony bodies (otoliths) surrounded by fluid and tissue, and detects sounds at frequencies from 30 to 500 Hz. Atlantic cod have also been shown to localize sounds. However, how their ears perform these functions is not fully understood. Steady streaming, or time-independent, flows near a 350% scale model Atlantic cod otolith immersed in a viscous fluid were studied to determine if these fluid flows contain acoustically relevant information that could be detected by the ear s sensory hair cells. The otolith was oscillated sinusoidally at various orientations at frequencies of 8 24 Hz, corresponding to an actual frequency range of 280 830 Hz. Phaselocked particle pathline visualizations of the resulting flows give velocity, vorticity, and rate of strain fields over a single plane of this mainly two-dimensional flow. Although the streaming flows contain acoustically relevant information, the displacements due to these flows are likely too small to explain Atlantic cod hearing abilities near threshold. The results, however, may suggest a possible mechanism for detection of ultrasound in some fish species.

  13. Performance Analysis of Single Photon Avalanche Diode Underwater VLC System Using ARQ

    KAUST Repository

    Shafiqu, Taniya

    2017-08-24

    Single photon avalanche diode (SPAD) has recently been introduced as a powerful detector for long distance underwater visible light (UVLC) communication. In this paper, the performance of the SPAD detector in UVLC is analyzed considering the effect of the turbulence induced fading resulting from air bubbles in addition to the combined effect of attenuation and scattering. Automatic repeat request (ARQ) system is adopted to mitigate different underwater impairments and reduce the error probability at the receiver side. Approximate packet error rate (PER) expressions are derived using Laguerre Gauss polynomial for a finite number of transmission. Next, the average energy efficiency and throughput are analyzed to account for the increased energy consumption cost and the decreased effective transmission rate, which results from adopting the ARQ scheme. Finally, different numerical results are introduced to verify the derived PER expressions, demonstrate the ability of the proposed ARQ system in extending the transmission range, and show the trade-off between energy efficiency (EE) and throughput.

  14. Photoactivatable Mussel-Based Underwater Adhesive Proteins by an Expanded Genetic Code.

    Science.gov (United States)

    Hauf, Matthias; Richter, Florian; Schneider, Tobias; Faidt, Thomas; Martins, Berta M; Baumann, Tobias; Durkin, Patrick; Dobbek, Holger; Jacobs, Karin; Möglich, Andreas; Budisa, Nediljko

    2017-09-19

    Marine mussels exhibit potent underwater adhesion abilities under hostile conditions by employing 3,4-dihydroxyphenylalanine (DOPA)-rich mussel adhesive proteins (MAPs). However, their recombinant production is a major biotechnological challenge. Herein, a novel strategy based on genetic code expansion has been developed by engineering efficient aminoacyl-transfer RNA synthetases (aaRSs) for the photocaged noncanonical amino acid ortho-nitrobenzyl DOPA (ONB-DOPA). The engineered ONB-DOPARS enables in vivo production of MAP type 5 site-specifically equipped with multiple instances of ONB-DOPA to yield photocaged, spatiotemporally controlled underwater adhesives. Upon exposure to UV light, these proteins feature elevated wet adhesion properties. This concept offers new perspectives for the production of recombinant bioadhesives. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Negotiating hearing disability and hearing disabled identities

    DEFF Research Database (Denmark)

    Lykke Hindhede, Anette

    2012-01-01

        Using disability theory as a framework and social science theories of identity to strengthen the arguments, this paper explores empirically how working-age adults confront the medical diagnosis of hearing impairment. For most participants hearing impairment threatens the stability of social...... interaction and the construction of hearing disabled identities is seen as shaped in the interaction with the hearing impaired person‟s surroundings. In order to overcome the potential stigmatisation the „passing‟ as normal becomes predominant. For many the diagnosis provokes radical redefinitions of the self....... The discursively produced categorisation and subjectivity of senescence mean that rehabilitation technologies such as hearing aids identify a particular life-style (disabled) which determines their social significance. Thus wearing a hearing aid works against the contemporary attempt to create socially ideal...

  16. An Evaluation of Potential Operating Systems for Autonomous Underwater Vehicles

    Science.gov (United States)

    2013-02-01

    remote control of such vehicles requires the use of a tether , limiting the vehicle’s range; however operating underwater vehicles autonomously requires...URBI Universal Robot Body Interface UUV Unmanned Underwater Vehicle UNCLASSIFIED xi DSTO–TN–1194 UNCLASSIFIED THIS PAGE IS INTENTIONALLY BLANK xii... underwater environment, where many platforms are still reliant upon an umbilical tether for power and high bandwidth communications. This tether

  17. On the Performance of the Underwater Acoustic Sensor Networks

    Science.gov (United States)

    2015-05-01

    waves for Underwater Wireless Communication (UWC); radio waves, optical waves, and acoustic waves are few to name. Radio waves are good for extra low...2211 underwater communication , wireless sensors, mutual information REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR...Cotae, “On the Performance of the Underwater Wireless Communication Sensor Networks: Work in Progress” ASEE Mid-Atlantic Fall 2014 Conference

  18. Underwater laser beam welding of Alloy 690

    International Nuclear Information System (INIS)

    Hino, Takehisa; Tamura, Masataka; Kono, Wataru; Kawano, Shohei; Yoda, Masaki

    2009-01-01

    Stress Corrosion Clacking (SCC) has been reported at Alloy 600 welds between nozzles and safe-end in Pressurized Water Reactor (PWR) plant. Alloy 690, which has higher chromium content than Alloy 600, has been applied for cladding on Alloy 600 welds for repairing damaged SCC area. Toshiba has developed Underwater Laser Beam Welding technique. This method can be conducted without draining, so that the repairing period and the radiation exposure during the repair can be dramatically decreased. In some old PWRs, high-sulfur stainless steel is used as the materials for this section. It has a high susceptibility of weld cracks. Therefore, the optimum welding condition of Alloy 690 on the high-sulfur stainless steel was investigated with our Underwater Laser Beam Welding unit. Good cladding layer, without any crack, porosity or lack of fusion, could be obtained. (author)

  19. Cymbal and BB underwater transducers and arrays

    Energy Technology Data Exchange (ETDEWEB)

    Newnham, R.E.; Zhang, J.; Alkoy, S.; Meyer, R.; Hughes, W.J.; Hladky-Hennion, A.C.; Cochran, J.; Markley, D. [Materials Research Laboratory, Penn State University, University Park, PA 16802 (United States)

    2002-09-01

    The cymbal is a miniaturized class V flextensional transducer that was developed for use as a shallow water sound projector and receiver. Single elements are characterized by high Q, low efficiency, and medium power output capability. Its low cost and thin profile allow the transducer to be assembled into large flexible arrays. Efforts were made to model both single elements and arrays using the ATILA code and the integral equation formulation (EQI).Millimeter size microprobe hydrophones (BBs) have been designed and fabricated from miniature piezoelectric hollow ceramic spheres for underwater applications such as mapping acoustic fields of projectors, and flow noise sensors for complex underwater structures. Green spheres are prepared from soft lead zirconate titanate powders using a coaxial nozzle slurry process. A compact hydrophone with a radially-poled sphere is investigated using inside and outside electrodes. Characterization of these hydrophones is done through measurement of hydrostatic piezoelectric charge coefficients, free field voltage sensitivities and directivity beam patterns. (orig.)

  20. Underwater noise modelling for environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Farcas, Adrian [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom); Thompson, Paul M. [Lighthouse Field Station, Institute of Biological and Environmental Sciences, University of Aberdeen, Cromarty IV11 8YL (United Kingdom); Merchant, Nathan D., E-mail: nathan.merchant@cefas.co.uk [Centre for Environment, Fisheries and Aquaculture Science (Cefas), Pakefield Road, Lowestoft, NR33 0HT (United Kingdom)

    2016-02-15

    Assessment of underwater noise is increasingly required by regulators of development projects in marine and freshwater habitats, and noise pollution can be a constraining factor in the consenting process. Noise levels arising from the proposed activity are modelled and the potential impact on species of interest within the affected area is then evaluated. Although there is considerable uncertainty in the relationship between noise levels and impacts on aquatic species, the science underlying noise modelling is well understood. Nevertheless, many environmental impact assessments (EIAs) do not reflect best practice, and stakeholders and decision makers in the EIA process are often unfamiliar with the concepts and terminology that are integral to interpreting noise exposure predictions. In this paper, we review the process of underwater noise modelling and explore the factors affecting predictions of noise exposure. Finally, we illustrate the consequences of errors and uncertainties in noise modelling, and discuss future research needs to reduce uncertainty in noise assessments.

  1. Ocean Research Enabled by Underwater Gliders

    Science.gov (United States)

    Rudnick, Daniel L.

    2016-01-01

    Underwater gliders are autonomous underwater vehicles that profile vertically by changing their buoyancy and use wings to move horizontally. Gliders are useful for sustained observation at relatively fine horizontal scales, especially to connect the coastal and open ocean. In this review, research topics are grouped by time and length scales. Large-scale topics addressed include the eastern and western boundary currents and the regional effects of climate variability. The accessibility of horizontal length scales of order 1 km allows investigation of mesoscale and submesoscale features such as fronts and eddies. Because the submesoscales dominate vertical fluxes in the ocean, gliders have found application in studies of biogeochemical processes. At the finest scales, gliders have been used to measure internal waves and turbulent dissipation. The review summarizes gliders' achievements to date and assesses their future in ocean observation.

  2. Hearing Aid and children

    Directory of Open Access Journals (Sweden)

    Jamileh Fatahi

    2002-07-01

    Full Text Available In order to develop oral communication, hearing impaired infants and young children must be able to hear speech comfortably and consistently. To day children with all degrees of hearing loss may be condidates for some kinds of amlification. As children differ from adults, many Factors should be consider in hearing aid selection, evaluation and fitting. For example the child age when he or she is candidate for custom instruments? Do we consider programmable Hearing aid? Are multi memory instruments appropriate for them? What about directional microphones? What style of hearing aid do we select? In this paper such questions are Answered.

  3. Congenital hearing impairment

    International Nuclear Information System (INIS)

    Robson, Caroline D.

    2006-01-01

    Establishing the etiology of congenital hearing impairment can significantly improve treatment for certain causes of hearing loss and facilitates genetic counseling. High-resolution CT and MRI have contributed to the evaluation and management of hearing impairment. In addition, with the identification of innumerable genetic loci and genetic defects involved in hearing loss, genetic testing has emerged as an invaluable tool in the assessment of hearing impairment. Some of the common forms of congenital hearing loss are reviewed and their imaging features illustrated. (orig.)

  4. A MAC protocol for underwater sensors networks

    OpenAIRE

    Santos, Rodrigo; Orozco, Javier; Ochoa, Sergio; Meseguer Pallarès, Roc; Eggly, Gabriel

    2015-01-01

    “The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-26401-1_37." Underwater sensor networks are becoming an important field of research, because of its everyday increasing application scope. Examples of their application areas are environmental and pollution monitoring (mainly oil spills), oceanographic data collection, support for submarine geo-localization, ocean sampling and early tsunamis alert. It is well-known the challenge that represents to perfo...

  5. Passive Mode Carbon Nanotube Underwater Acoustic Transducer

    Science.gov (United States)

    2016-09-20

    irreversible Joule heat) by an electric light bulb . The reciprocal (or reverse) of this process by supplying heat and shining light to the same electric bulb ...limit the invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching...300151 1 of 14 PASSIVE MODE CARBON NANOTUBE UNDERWATER ACOUSTIC TRANSDUCER STATEMENT OF GOVERNMENT INTEREST [0001] The invention described

  6. Underwater suction device for irradiated materials

    International Nuclear Information System (INIS)

    Qurnell, F.D.; Peloquin, A.V.

    1982-01-01

    An underwater suction device for collecting irradiated materials in a pool of water includes injection and suction tubes and a removable, disposable filter for capturing irradiated materials. Pressurized water is injected into the suction tube through a jet pump nozzle to establish a suction flow through the tube. The suction device is manoeuverable by a pole, which is pivotally connected to the suction device by a latching mechanism. (author)

  7. Tethered Antennas for Unmanned Underwater Vehicles

    Science.gov (United States)

    2009-04-27

    Concepts The first design (Figure 1) was based on the concept of an airfoil kite. The shape of the tow body was built around a NACA5515 hydrofoil to...Underwater Vehicles Brooke Ocean Technology (USA) Inc. 6 Figure 1: Hydrofoil Design The second design was based on that of a boat hull...communications. A sharp bow was utilized to cut through the water to reduce drag when on the surface. Like the hydrofoil design the top profile was

  8. MEDITERRANEAN: Underwater neutrinos get off the ground

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Now funded is the initial stage of NESTOR, an imaginative new programme for a dedicated underwater neutrino astroparticle physics laboratory. Located in the international waters off the southernmost corner of continental Europe near the town of Pylos in S.W. Greece, NESTOR (NEutrinos from Supernovae and TeV sources Ocean Range) recalls the wise king of Pylos who counselled the Greeks during the Trojan war, an excellent tradition for new scientific goals of detecting neutrinos

  9. Role of Confined Water in Underwater Adhesion

    Science.gov (United States)

    Dhinojwala, Ali

    Surface bound water is a strong deterrent for forming strong bonds between two surfaces underwater and expelling that bound water is important for strong adhesion. I will discuss examples of different strategies used by geckos, spiders, and mussels to handle this last layer of bound water. Recent results using infrared-visible sum frequency generation spectroscopy to probe the structure of this bound water will be discussed. National Science Foundation.

  10. Obstacle avoidance in underwater glider path planning

    OpenAIRE

    Isern González, Josep; Hernández Sosa, Daniel; Fernández Perdomo, Enrique; Cabrera Gámez, Jorge; Domínguez Brito, Antonio Carlos; Prieto Marañón, Víctor

    2012-01-01

    Underwater gliders have revealed as a valuable scientific platform, with a growing number of successful environmental sampling applications. They are specially suited for long range missions due to their unmatched autonomy level, although their low surge speed make them strongly affected by ocean currents. Path planning constitute a real concern for this type of vehicle, as it may reduce the time taken to reach a given waypoint or save power. In such a dynamic environment it is not easy to fi...

  11. A Recovery System for Unmanned Underwater Vehicles

    Science.gov (United States)

    2017-09-28

    300170 1 of 10 A RECOVERY SYSTEM FOR UNMANNED UNDERWATER VEHICLES STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may...6 of 10 forces cannot be easily predicted and can be strong enough to require a significantly larger handling system and significantly more...the sea state, the ship handling system , the capture mechanism and the design of the capture mechanism 400. [0024] The water jets 100 will increase

  12. Story retelling skills in Persian speaking hearing-impaired children.

    Science.gov (United States)

    Jarollahi, Farnoush; Mohamadi, Reyhane; Modarresi, Yahya; Agharasouli, Zahra; Rahimzadeh, Shadi; Ahmadi, Tayebeh; Keyhani, Mohammad-Reza

    2017-05-01

    Since the pragmatic skills of hearing-impaired Persian-speaking children have not yet been investigated particularly through story retelling, this study aimed to evaluate some pragmatic abilities of normal-hearing and hearing-impaired children using a story retelling test. 15 normal-hearing and 15 profound hearing-impaired 7-year-old children were evaluated using the story retelling test with the content validity of 89%, construct validity of 85%, and reliability of 83%. Three macro structure criteria including topic maintenance, event sequencing, explicitness, and four macro structure criteria including referencing, conjunctive cohesion, syntax complexity, and utterance length were assessed. The test was performed with live voice in a quiet room where children were then asked to retell the story. The tasks of the children were recorded on a tape, transcribed, scored and analyzed. In the macro structure criteria, utterances of hearing-impaired students were less consistent, enough information was not given to listeners to have a full understanding of the subject, and the story events were less frequently expressed in a rational order than those of normal-hearing group (P hearing students who obtained high scores, hearing-impaired students failed to gain any scores on the items of this section. These results suggest that Hearing-impaired children were not able to use language as effectively as their hearing peers, and they utilized quite different pragmatic functions. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Self-Esteem in Children and Adolescents With Hearing Loss

    Directory of Open Access Journals (Sweden)

    Andrea D. Warner-Czyz

    2015-03-01

    Full Text Available Children with hearing loss are at risk for lower self-esteem due to differences from hearing peers relative to communication skills, physical appearance, and social maturity. This study examines the influence of generic factors unrelated to hearing loss (e.g., age, gender, temperament and specific factors associated with hearing loss (e.g., age at identification, communication skills on how children with hearing loss wearing cochlear implants or hearing aids appraise self-esteem. Fifty children with hearing loss wearing cochlear implants or hearing aids participated (Mean age: 12.88 years; mean duration of device use: 3.43 years. Participants independently completed online questionnaires to assess communication skills, social engagement, self-esteem, and temperament. Children with hearing loss rated global self-esteem significantly more positively than hearing peers, t = 2.38, p = .02. Self-esteem ratings attained significant positive correlations with affiliation (r = .42, p = .002 and attention (r = .45, p = .001 temperaments and a significant negative association with depressive mood (r = − .60, p < .0001. No significant correlations emerged between self-esteem and demographic factors, communication skills, or social engagement. Because successful communication abilities do not always co-occur with excellent quality of life, clinicians and professionals working with children with hearing loss need to understand components contributing to self-esteem to improve identification, counseling, and external referrals for children in this population.

  14. Self-Esteem in Children and Adolescents With Hearing Loss

    Science.gov (United States)

    Loy, Betty A.; Evans, Christine; Wetsel, Ashton; Tobey, Emily A.

    2015-01-01

    Children with hearing loss are at risk for lower self-esteem due to differences from hearing peers relative to communication skills, physical appearance, and social maturity. This study examines the influence of generic factors unrelated to hearing loss (e.g., age, gender, temperament) and specific factors associated with hearing loss (e.g., age at identification, communication skills) on how children with hearing loss wearing cochlear implants or hearing aids appraise self-esteem. Fifty children with hearing loss wearing cochlear implants or hearing aids participated (Mean age: 12.88 years; mean duration of device use: 3.43 years). Participants independently completed online questionnaires to assess communication skills, social engagement, self-esteem, and temperament. Children with hearing loss rated global self-esteem significantly more positively than hearing peers, t = 2.38, p = .02. Self-esteem ratings attained significant positive correlations with affiliation (r = .42, p = .002) and attention (r = .45, p = .001) temperaments and a significant negative association with depressive mood (r = − .60, p self-esteem and demographic factors, communication skills, or social engagement. Because successful communication abilities do not always co-occur with excellent quality of life, clinicians and professionals working with children with hearing loss need to understand components contributing to self-esteem to improve identification, counseling, and external referrals for children in this population. PMID:25755025

  15. Current amplification models of sensorineurall and conductive hearing loss

    Directory of Open Access Journals (Sweden)

    Ostojić Sanja

    2012-01-01

    Full Text Available The main function of a hearing aid is to improve auditory and language abilities of hearing impaired users. The amplification model has to be adapted according to age, degree and type of hearing loss. The goal of this paper is to analyze the current amplification models of sensorineural and conductive hearing loss which can provide a high quality of speech perception and sounds at any degree of hearing loss. The BAHA is a surgically implantable system for treatment of conductive hearing loss that works through direct bone conduction. BAHA is used to help people with chronic ear infections, congenital external auditory canal atresia and single sided deafness who cannot benefit from conventional hearing aids. The last generation of hearing aid for sensorineural hearing loss is cochlear implant. Bimodal amplification improves binaural hearing. Hearing aids alone do not make listening easier in all situations. The things that can interfere with listening are background noises, distance from a sound and reverberation or echo. The device used most often today is the Frequency Modulated (FM system.

  16. Research on Operational Aspects of Large Autonomous Underwater Glider Fleets

    National Research Council Canada - National Science Library

    Fratantoni, David M

    2007-01-01

    This program supported research on the operational and management issues stemming from application of large fleets of autonomous underwater gliders to oceanographic research and rapid environmental...

  17. Calibration Techniques for Accurate Measurements by Underwater Camera Systems.

    Science.gov (United States)

    Shortis, Mark

    2015-12-07

    Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems.

  18. Calibration Techniques for Accurate Measurements by Underwater Camera Systems

    Directory of Open Access Journals (Sweden)

    Mark Shortis

    2015-12-01

    Full Text Available Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This paper reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems.

  19. Automatic stabilization of underwater robots in the time manipulation operations

    International Nuclear Information System (INIS)

    Filaretov, V.F.; Koval, E.V.

    1994-01-01

    When carrying out underwater technical works by means of an underwater vehicles having a manipulator it is desirable to perform manipulation operations in the regime of the underwater vehicle hovering above the object without durable and complicated operations up its rigid fixation. Underwater vehicle stabilization is achieved by compensation all the effects on the vehicle caused by the operating manipulator in water medium. This automatic stabilization is formed due to input of the required control signals into corresponding vehicle propellers proportional to calculated components of the generalized forces and moments. The propellers should form stops reacting against effects

  20. Contour Tracking Control for the REMUS Autonomous Underwater Vehicle

    National Research Council Canada - National Science Library

    Van Reet, Alan R

    2005-01-01

    In the interest of enhancing the capabilities of autonomous underwater vehicles used in US Naval Operations, controlling vehicle position to follow depth contours presents exciting potential for navigation...

  1. Autopilot Using Differential Thrust for ARIES Autonomous Underwater Vehicle

    National Research Council Canada - National Science Library

    Sarton, Christopher

    2003-01-01

    .... Unfortunately, communication antennas must point to specific satellites in this system and thus underwater vehicles must steer a specific course on the surface during the communication process...

  2. Influence of range-gated intensifiers on underwater imaging system SNR

    Science.gov (United States)

    Wang, Xia; Hu, Ling; Zhi, Qiang; Chen, Zhen-yue; Jin, Wei-qi

    2013-08-01

    Range-gated technology has been a hot research field in recent years due to its high effective back scattering eliminating. As a result, it can enhance the contrast between a target and its background and extent the working distance of the imaging system. The underwater imaging system is required to have the ability to image in low light level conditions, as well as the ability to eliminate the back scattering effect, which means that the receiver has to be high-speed external trigger function, high resolution, high sensitivity, low noise, higher gain dynamic range. When it comes to an intensifier, the noise characteristics directly restrict the observation effect and range of the imaging system. The background noise may decrease the image contrast and sharpness, even covering the signal making it impossible to recognize the target. So it is quite important to investigate the noise characteristics of intensifiers. SNR is an important parameter reflecting the noise features of a system. Through the use of underwater laser range-gated imaging prediction model, and according to the linear SNR system theory, the gated imaging noise performance of the present market adopted super second generation and generation Ⅲ intensifiers were theoretically analyzed. Based on the active laser underwater range-gated imaging model, the effect to the system by gated intensifiers and the relationship between the system SNR and MTF were studied. Through theoretical and simulation analysis to the image intensifier background noise and SNR, the different influence on system SNR by super second generation and generation Ⅲ ICCD was obtained. Range-gated system SNR formula was put forward, and compared the different effect influence on the system by using two kind of ICCDs was compared. According to the matlab simulation, a detailed analysis was carried out theoretically. All the work in this paper lays a theoretical foundation to further eliminating back scattering effect, improving

  3. Underwater Acoustic Target Tracking: A Review.

    Science.gov (United States)

    Luo, Junhai; Han, Ying; Fan, Liying

    2018-01-02

    Advances in acoustic technology and instrumentation now make it possible to explore marine resources. As a significant component of ocean exploration, underwater acoustic target tracking has aroused wide attention both in military and civil fields. Due to the complexity of the marine environment, numerous techniques have been proposed to obtain better tracking performance. In this paper, we survey over 100 papers ranging from innovative papers to the state-of-the-art in this field to present underwater tracking technologies. Not only the related knowledge of acoustic tracking instrument and tracking progress is clarified in detail, but also a novel taxonomy method is proposed. In this paper, algorithms for underwater acoustic target tracking are classified based on the methods used as: (1) instrument-assisted methods; (2) mode-based methods; (3) tracking optimization methods. These algorithms are compared and analyzed in the aspect of dimensions, numbers, and maneuvering of the tracking target, which is different from other survey papers. Meanwhile, challenges, countermeasures, and lessons learned are illustrated in this paper.

  4. Underwater detection by using ultrasonic sensor

    Science.gov (United States)

    Bakar, S. A. A.; Ong, N. R.; Aziz, M. H. A.; Alcain, J. B.; Haimi, W. M. W. N.; Sauli, Z.

    2017-09-01

    This paper described the low cost implementation of hardware and software in developing the system of ultrasonic which can visualize the feedback of sound in the form of measured distance through mobile phone and monitoring the frequency of detection by using real time graph of Java application. A single waterproof transducer of JSN-SR04T had been used to determine the distance of an object based on operation of the classic pulse echo detection method underwater. In this experiment, the system was tested by placing the housing which consisted of Arduino UNO, Bluetooth module of HC-06, ultrasonic sensor and LEDs at the top of the box and the transducer was immersed in the water. The system which had been tested for detection in vertical form was found to be capable of reporting through the use of colored LEDs as indicator to the relative proximity of object distance underwater form the sensor. As a conclusion, the system can detect the presence of an object underwater within the range of ultrasonic sensor and display the measured distance onto the mobile phone and the real time graph had been successfully generated.

  5. Modeling and Control of Underwater Robotic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Schjoelberg, I:

    1996-12-31

    This doctoral thesis describes modeling and control of underwater vehicle-manipulator systems. The thesis also presents a model and a control scheme for a system consisting of a surface vessel connected to an underwater robotic system by means of a slender marine structure. The equations of motion of the underwater vehicle and manipulator are described and the system kinematics and properties presented. Feedback linearization technique is applied to the system and evaluated through a simulation study. Passivity-based controllers for vehicle and manipulator control are presented. Stability of the closed loop system is proved and simulation results are given. The equation of motion for lateral motion of a cable/riser system connected to a surface vessel at the top end and to a thruster at the bottom end is described and stability analysis and simulations are presented. The equations of motion in 3 degrees of freedom of the cable/riser, surface vessel and robotic system are given. Stability analysis of the total system with PD-controllers is presented. 47 refs., 32 figs., 7 tabs.

  6. Underwater Noise Modelling of Wave Energy Devices

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Future large-scale implementation of wave energy converts (WECs) will introduce an anthropogenic activity in the ocean which may contribute to underwater noise. The Ocean houses several marine species with acoustic sensibility; consequently the potential impact of the underwater noise needs to be addressed. At present, there are no acoustic impact studies based on acquired data. The WEAM project (Wave Energy Acoustic Monitoring) aims at developing an underwater noise monitoring plan for WECs. The development of an acoustic monitoring plan must consider the sound propagation in the ocean, identify noise sources, understand the operational characteristics and select adequate instrumentation. Any monitoring strategy must involve in-situ measurements. However, the vast distances which sound travels within the ocean, can make in-situ measurements covering the entire area of interest, impracticable. This difficulty can be partially overcome through acoustic numerical modelling. This paper presents a synthetic study, on the application of acoustic forward modelling and the evaluation of the impact of noise produced by wave energy devices on marine mammals using criteria based on audiograms of dolphins, or other species. The idea is to illustrate the application of that methodology, and to show to what extent it allows for estimating distances of impacts due to acoustic noise.

  7. Educational Implications of Conductive Hearing Loss in School Children.

    Science.gov (United States)

    Lyon, David J.; And Others

    1986-01-01

    The study investigated specific linguistic abilities/disabilities of 15 children with conductive hearing loss and a history of middle ear dysfunction. Results found significant deficits in verbal intelligence, word recognition, and receptive syntactic skills substantiating the finding that conductive hearing loss due to otitis media is deleterious…

  8. Prevalence of hearing loss and accuracy of self-report among factory workers.

    Science.gov (United States)

    McCullagh, Marjorie C; Raymond, Delbert; Kerr, Madeleine J; Lusk, Sally L

    2011-01-01

    Noise represents one of the most common occupational health hazards. A Healthy People 2020 objective aims to reduce hearing loss in the noise-exposed public. The purpose of this study was to describe and compare perceived and measured hearing, and to determine the prevalence of hearing loss among a group of factory workers. Data collected as part of an intervention study promoting hearing protector use among workers at an automotive factory in the Midwest were used. Plant employees (n=2691) provided information regarding their perceived hearing ability, work role, and other demographics. The relationships among audiograms, a single-item measure of perceived hearing ability, and demographic data were explored using chi-square, McNemar's test, Mann-Whitney U-test, sensitivity, and specificity. The prevalence of hearing loss among noise-exposed factory workers was 42% (where hearing loss was defined as >25 dB loss at the OSHA-recommended frequencies of 2, 3, and 4 kHz in either ear). However, 76% of workers reported their hearing ability as excellent or good. The difference in perceived hearing ability was significant at each tested frequency between those with and without measured hearing loss. Self-reported hearing ability was poorly related to results of audiometry. Although this group of workers was employed in a regulated environment and served by a hearing conservation program, hearing loss was highly prevalent. These findings, together with national prevalence estimates, support the need for evaluation of hearing conservation programs and increased attention to the national goal of reducing adult hearing loss.

  9. Prevalence of hearing loss and accuracy of self-report among factory workers

    Directory of Open Access Journals (Sweden)

    Marjorie C McCullagh

    2011-01-01

    Full Text Available Noise represents one of the most common occupational health hazards. A Healthy People 2020 objective aims to reduce hearing loss in the noise-exposed public. The purpose of this study was to describe and compare perceived and measured hearing, and to determine the prevalence of hearing loss among a group of factory workers. Data collected as part of an intervention study promoting hearing protector use among workers at an automotive factory in the Midwest were used. Plant employees (n=2691 provided information regarding their perceived hearing ability, work role, and other demographics. The relationships among audiograms, a single-item measure of perceived hearing ability, and demographic data were explored using chi-square, McNemar′s test, Mann-Whitney U-test, sensitivity, and specificity. The prevalence of hearing loss among noise-exposed factory workers was 42% (where hearing loss was defined as >25 dB loss at the OSHA-recommended frequencies of 2, 3, and 4 kHz in either ear. However, 76% of workers reported their hearing ability as excellent or good. The difference in perceived hearing ability was significant at each tested frequency between those with and without measured hearing loss. Self-reported hearing ability was poorly related to results of audiometry. Although this group of workers was employed in a regulated environment and served by a hearing conservation program, hearing loss was highly prevalent. These findings, together with national prevalence estimates, support the need for evaluation of hearing conservation programs and increased attention to the national goal of reducing adult hearing loss.

  10. Pediatric hearing impairment caregiver experience: impact of duration of hearing loss on parental stress.

    Science.gov (United States)

    Meinzen-Derr, Jareen; Lim, Lynne H Y; Choo, Daniel I; Buyniski, Samantha; Wiley, Susan

    2008-11-01

    Caregivers of children who are deaf/hard of hearing have been reported to have greater stress than caregivers of children with normal hearing. The time of diagnosis is a particularly stressful time and stress levels may change over time based on varying needs at different life events. Thus, we hypothesized that stress experienced by caregivers evolves over time and is impacted by the duration since the diagnosis of hearing loss. The 68-item pediatric hearing impairment caregiver experience (PHICE) is a validated questionnaire used to measure stress. The PHICE was administered to 152 caregivers of children with permanent hearing loss. Domain scores were converted into z-scores for analysis of trends of stress over time. Parents of children whose hearing loss was identified more than 60 months ago reported higher stress levels regarding educational aspects of their child's needs as compared to parents of children with less than 24 months or 24-60 months duration since diagnosis. Parents of children diagnosed with hearing loss within the preceding 24 months reported higher stress levels in the area of healthcare than parents of children diagnosed greater than 24 months ago. Parental stressors change over time with respect to the time of diagnosis of hearing impairment. This phenomenon was observed irrespective of the age of diagnosis of hearing loss. As professionals serving families of children with hearing loss, we should be aware of changing stressors over time and identify the appropriate support services for families to meet those changing needs. By addressing those evolving stressors, the families' ability to support and improve the outcomes for their children who are deaf or hard of hearing may be enhanced.

  11. Survey on Satisfaction Level With Hearing Aid in the Daily Life of Elderly Hearing Impaired Population

    Directory of Open Access Journals (Sweden)

    Mohsen Ahadi

    2008-01-01

    Full Text Available Objectives: The aim of the present study was to investigate satisfaction levels with hearing aids in daily life of older adult users, in addition to associated factors. Methods & Materials: In this cross sectional study, 32 subjects with moderate to severe sensory neural hearing loss (mean age; 63.5±9.8 Yrs and different socio-economic status, referred to private practice audiology clinic (Alltone Shenava audiology clinic, Newsha hearing rehabilitation center, Golriz audiology clinic, were selected to answer Farsi version of SADL (Satisfaction with Amplification in Daily Life questionnaire. This questionnaire quantifies satisfaction using a global score and four subscales. Based on history form, all subjects had moderate socio-economic status. Results: Mean score of Farsi Satisfaction with Amplification in Daily Life (SADL and respective correspondence of categorical scale were: Overall score 4.24±0.57 (min. 2.24 and max. 5.12; Medium satisfied; Positive effects 4.33±0.83; Medium to considerably satisfied; Services and costs 3.60±0.84; Somewhat satisfied; and Personal image 5.00±1.25; considerably satisfied. Difference between satisfaction level and experience with current hearing aid, daily hearing aid use, degree of hearing loss and educational level was significant (P<0.05 but there was no significant difference between sex (P<0.0566. Conclusion: Results of hearing aid satisfaction in geriatric hearing impaired population were less than those of the previous studies. Upon analyzing factors associated with satisfaction with the use of hearing aids, it seems that factors such as use of modem technology, evaluation of communication and listening needs (before and after hearing aid prescription, detailed consultation about abilities and limitations of this devices as well as improvement in public and social services, enhance the satisfaction with hearing aid use.

  12. Hearing Loss: Screening Newborns

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Hearing Loss Screening Newborns Past Issues / Spring 2015 Table of ... of newborns in the U.S. are screened for hearing loss before they leave the hospital. Research improves the ...

  13. Hearing Disorders and Deafness

    Science.gov (United States)

    ... impossible, to hear. They can often be helped. Deafness can keep you from hearing sound at all. ... certain medicines, and surgery. NIH: National Institute on Deafness and Other Communication Disorders

  14. Genes and Hearing Loss

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Genes and Hearing Loss Genes and Hearing Loss Patient ... mutation may only have dystopia canthorum. How Do Genes Work? Genes are a road map for the ...

  15. Occupational hearing loss

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/001048.htm Occupational hearing loss To use the sharing features on this page, please enable JavaScript. Occupational hearing loss is damage to the inner ear from noise ...

  16. What's Hearing Loss?

    Science.gov (United States)

    ... Loss There are a few different types of hearing loss: conductive , sensorineural , mixed (conductive and sensory combined), neural , and central . Conductive (say: kun- duk -tiv) hearing loss. This happens when there is a problem with ...

  17. Noise and Hearing Protection

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Noise and Hearing Protection Noise and Hearing Protection Patient ... it is. How can I tell if a noise is dangerous? People differ in their sensitivity to ...

  18. Hearing and the cochlea

    Science.gov (United States)

    ... like structure that contains the receptor organ for hearing. The cochlea contains the spiral organ of Corti, which is the receptor organ for hearing. It consists of tiny hair cells that translate ...

  19. Auditory, Visual, and Auditory-Visual Perceptions of Emotions by Young Children with Hearing Loss versus Children with Normal Hearing

    Science.gov (United States)

    Most, Tova; Michaelis, Hilit

    2012-01-01

    Purpose: This study aimed to investigate the effect of hearing loss (HL) on emotion-perception ability among young children with and without HL. Method: A total of 26 children 4.0-6.6 years of age with prelingual sensory-neural HL ranging from moderate to profound and 14 children with normal hearing (NH) participated. They were asked to identify…

  20. Validation of the Korean Version of the Spatial Hearing Questionnaire for Assessing the Severity and Symmetry of Hearing Impairment.

    Science.gov (United States)

    Kong, Tae Hoon; Park, Yoon Ah; Bong, Jeong Pyo; Park, Sang Yoo

    2017-07-01

    Spatial hearing refers to the ability to understand speech and identify sounds in various environments. We assessed the validity of the Korean version of the Spatial Hearing Questionnaire (K-SHQ). We performed forward translation of the original English SHQ to Korean and backward translation from the Korean to English. Forty-eight patients who were able to read and understand Korean and received a score of 24 or higher on the Mini-Mental Status Examination were included in the study. Patients underwent pure tone audiometry (PTA) using a standard protocol and completed the K-SHQ. Internal consistency was evaluated using Cronbach's alpha, and factor analysis was performed to prove reliability. Construct validity was tested by comparing K-SHQ scores from patients with normal hearing to those with hearing impairment. Scores were compared between subjects with unilateral or bilateral hearing loss and between symmetrical and asymmetrical hearing impairment. Cronbach's alpha showed good internal consistency (0.982). Two factors were identified by factor analysis: There was a significant difference in K-SHQ scores for patients with normal hearing compared to those with hearing impairment. Patients with asymmetric hearing impairment had higher K-SHQ scores than those with symmetric hearing impairment. This is related to a lower threshold of PTA in the better ear of subjects. The hearing ability of the better ear is correlated with K-SHQ score. The K-SHQ is a reliable and valid tool with which to assess spatial hearing in patients who speak and read Korean. K-SHQ score reflects the severity and symmetry of hearing impairment.

  1. Deafness and Hearing Loss.

    Science.gov (United States)

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This brief overview provides information on the definition, incidence, and characteristics of children with hearing impairments and deafness. The federal definitions of hearing impairment and deafness are provided. The different types of hearing loss are noted, including: (1) conductive (caused by diseases or obstructions in the outer or middle…

  2. Differences in self-advocacy among hard of hearing and typical hearing students.

    Science.gov (United States)

    Michael, Rinat; Zidan, Haya Maroon

    2018-01-01

    Self-advocacy is considered a protective factor of psychosocial and academic problems among students with special needs. To asses self-advocacy among students with hearing loss and compare it to that of typical hearing students. The current study examined 27 hard of hearing (hh) students and 27 typical hearing students, all studying in mainstream classes. They completed the Hope Scale, a self-esteem scale, a self-efficacy scale, and a measure of self-advocacy statements. Data regarding the hh participants' spoken language abilities were collected through their itinerant teachers. HH students reported lower levels of self-esteem than the typical hearing students. Emotional self-efficacy was positively correlated with age among the hh students, and hope and effort were negatively correlated with age among typical hearing students. Some significant positive correlations emerged among the hh participants between their syntactic and pragmatic abilities and several self-advocacy indicators. Interventions aimed at enhancing self-advocacy among hh students should focus on intensifying their self-esteem as well as their syntactic and pragmatic abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Are hearing aid owners able to identify and self-report handling difficulties? A pilot study.

    Science.gov (United States)

    Bennett, Rebecca J; Meyer, Carly; Olaithe, Michelle; Schmulian, Dunay; Eikelboom, Robert H

    2017-11-01

    Although clinician administered surveys evaluating hearing aid handling skills exist, the development of a self-administered version may reduce clinical load, save consultation time, and facilitate more frequent use than face-to-face consultations allow. However, there is currently no evidence to support whether hearing aid owners can accurately self-report hearing aid handling skills via self-report survey that systematically evaluates the ability to accurately perform the individual aspects of hearing aid handling required for effective hearing aid management. An explorative pilot study using a prospective research design. Nineteen adult hearing aid owners, aged between 65 and 93 years. The self-administered survey demonstrated high sensitivity when compared with clinician evaluation of skills, with 93% of participants accurately self-identifying and reporting whether hearing aid handling skill training was required. Hearing aid owners are able to accurately self-report hearing aid handling difficulties when provided with an itemised list of skills.

  4. Hearing testing in the U.S. Department of Defense: Potential impact on Veterans Affairs hearing loss disability awards.

    Science.gov (United States)

    Nelson, J T; Swan, A A; Swiger, B; Packer, M; Pugh, M J

    2017-06-01

    Hearing loss is the second most common disability awarded by the U.S. Department of Veterans Affairs (VA) to former members of the U.S. uniformed services. Hearing readiness and conservation practices differ among the four largest uniformed military services (Air Force, Army, Marine Corps, and Navy). Utilizing a data set consisting of all hearing loss claims submitted to the VA from fiscal years 2003-2013, we examined characteristics of veterans submitting claims within one year of separation from military service. Our results indicate that having a hearing loss disability claim granted was significantly more likely for men, individuals over the age of 26 years at the time of the claim, individuals most recently serving in the U.S. Army, and those with at least one hearing loss diagnosis. Importantly, individuals with at least one test record in the Defense Occupational and Environmental Health Readiness System-Hearing Conservation (DOEHRS-HC) system were significantly less likely to have a hearing loss disability claim granted by the VA. Within the DOEHRS-HC cohort, those with at least one threshold shift or clinical hearing loss diagnosis while on active duty were more than two and three times more likely to have a hearing loss disability claim granted, respectively. These findings indicate that an established history of reduced hearing ability while on active duty was associated with a significantly increased likelihood of an approved hearing loss disability claim relative to VA claims without such a history. Further, our results show a persistent decreased rate of hearing loss disability awards overall. These findings support increased inclusion of personnel in DoD hearing readiness and conservation programs to reduce VA hearing loss disability awards. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Development of underwater laser cutting technique for steel and ...

    Indian Academy of Sciences (India)

    We have developed underwater cutting technique for 4.2 mm thick zircaloy pressure tubes and up to 6 mm thick steel using fibre-coupled 250 W average power pulsed Nd:YAG laser. This underwater cutting technique will be highly useful in various nuclear applications as well as in dismantling/repair of ship and pipe lines ...

  6. Visual-adaptation-mechanism based underwater object extraction

    Science.gov (United States)

    Chen, Zhe; Wang, Huibin; Xu, Lizhong; Shen, Jie

    2014-03-01

    Due to the major obstacles originating from the strong light absorption and scattering in a dynamic underwater environment, underwater optical information acquisition and processing suffer from effects such as limited range, non-uniform lighting, low contrast, and diminished colors, causing it to become the bottleneck for marine scientific research and projects. After studying and generalizing the underwater biological visual mechanism, we explore its advantages in light adaption which helps animals to precisely sense the underwater scene and recognize their prey or enemies. Then, aiming to transform the significant advantage of the visual adaptation mechanism into underwater computer vision tasks, a novel knowledge-based information weighting fusion model is established for underwater object extraction. With this bionic model, the dynamical adaptability is given to the underwater object extraction task, making them more robust to the variability of the optical properties in different environments. The capability of the proposed method to adapt to the underwater optical environments is shown, and its outperformance for the object extraction is demonstrated by comparison experiments.

  7. Self-localization for underwater inspection robot in reactor systems

    International Nuclear Information System (INIS)

    Kobayashi, Futoshi; Kojima, Fumio

    2007-01-01

    An underwater inspection robot has been needed for preventive maintenance in a nuclear power plant. This paper deals with a self-localization method for the underwater inspection robot. In this method, the position and the orientation of the robot are estimated by using the particle filter. For showing the effectiveness of the proposed method, an experiment with real robot is demonstrated. (author)

  8. WODA technical guidance on underwater sound from dredging

    NARCIS (Netherlands)

    Thomsen, F.; Borsani, F.; Clarke, D.; Jong, C. de; Wit, P. de; Goethals, F.; Holtkamp, M.; Martin, E.S.; Spadaro, P.; Raalte, G. van; Victor, G.Y.V.; Jensen, A.

    2016-01-01

    The World Organization of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) prepared a guidance paper in 2013 on dredging sound, including a summary of potential impacts on aquatic

  9. Characterization of ships as sources of underwater noise

    NARCIS (Netherlands)

    Jong, C.A.F. de

    2009-01-01

    There is a growing interest in the possible impact of anthropogenic underwater noise on marine life [1]. One of the concerns is the increasing contribution of shipping noise, with the growing number and size of commercial ships. Traditionally, underwater radiated noise control was only of interest

  10. The WODA guidance paper on underwater sound from dredging (abstract)

    NARCIS (Netherlands)

    Thomsen, F.; Borsani, F.; Clarke, D.; Jong, C.A.F. de; Witt, P. de; Holtkamp, M.; Goethals, F.; San Martin, E.; Spadaro, P.; Raalte, G. van; Jensen, A.

    2013-01-01

    The World Organisation of Dredging Associations (WODA) has identified underwater sound as an environmental issue that needs further consideration. A WODA Expert Group on Underwater Sound (WEGUS) was established to provide a guidance paper on dredging sound, impact on aquatic biota and advice on

  11. Development of underwater laser cutting technique for steel and ...

    Indian Academy of Sciences (India)

    Laser cutting; underwater laser cutting; fibre optic beam delivery; Nd:YAG laser; material processing; heat affected zone; microstructure. PACS Nos 42.62.Cf; 42.62.-b; 42.55.Rz; 42.81.Ai; 42.81.-i. 1. Introduction. Underwater laser cutting and welding has many applications in nuclear facilities and shiping industry and is a ...

  12. Evaluation of an internet-based hearing test--comparison with established methods for detection of hearing loss.

    Science.gov (United States)

    Bexelius, Christin; Honeth, Louise; Ekman, Alexandra; Eriksson, Mikael; Sandin, Sven; Bagger-Sjöbäck, Dan; Litton, Jan-Eric

    2008-10-21

    Hearing impairment is most accurately measured by a clinical pure-tone audiogram. This method is not suitable for large-scale, population-based epidemiological studies as it requires that study participants visit a clinic with trained personnel. An alternative approach to measuring hearing ability is self-estimation through questionnaires, but the correlation to clinical audiometric tests varies. To evaluate an Internet-based hearing test pilot compared to a question about self-estimated hearing and the feasibility of using an Internet-based hearing test and an Internet-based questionnaire in a population of 560 members of the Swedish Hunters' Association in the age group 20-60 years. An invitation was mailed to the participants in March 2007 together with the URL to the study Web site, a personal username, and a password. The Web site included the questionnaire, the hearing test, and instructions for participating in the study. The hearing test resembles a clinical audiogram presenting 6 tones between 500 and 8000 Hz. Tones are presented between 0 and 60 dB, and the participant responds to the tones by pressing the space bar. The hearing test requires headphones and is based on JAVA programming. Before the participant can start the hearing test, it has to be calibrated against a reference person with good hearing between 15 and 35 years of age. After 5 months, 162 out of 560 (29%) had answered the questionnaire, out of which 88 (16%) had completed the hearing test. Those who actively declined participation numbered 230 out of 560 (41%). After removing duplicates and hearing tests calibrated by unreliable reference data, 61 hearing tests remained for analysis. The prevalence of hearing impairment from the Internet-based hearing test was 20% (12 out of 61), compared to 52% (32 out of 61) from the self-estimated question. Those who completed the hearing test were older than the non-participants, and more had headphones (P = .003) and the correct version of the JAVA

  13. HARDWARE REALIZATION OF CANNY EDGE DETECTION ALGORITHM FOR UNDERWATER IMAGE SEGMENTATION USING FIELD PROGRAMMABLE GATE ARRAYS

    Directory of Open Access Journals (Sweden)

    ALEX RAJ S. M.

    2017-09-01

    Full Text Available Underwater images raise new challenges in the field of digital image processing technology in recent years because of its widespread applications. There are many tangled matters to be considered in processing of images collected from water medium due to the adverse effects imposed by the environment itself. Image segmentation is preferred as basal stage of many digital image processing techniques which distinguish multiple segments in an image and reveal the hidden crucial information required for a peculiar application. There are so many general purpose algorithms and techniques that have been developed for image segmentation. Discontinuity based segmentation are most promising approach for image segmentation, in which Canny Edge detection based segmentation is more preferred for its high level of noise immunity and ability to tackle underwater environment. Since dealing with real time underwater image segmentation algorithm, which is computationally complex enough, an efficient hardware implementation is to be considered. The FPGA based realization of the referred segmentation algorithm is presented in this paper.

  14. Hearing Aids Communication

    DEFF Research Database (Denmark)

    Globally, hearing loss is the second most frequent disability. About 80% of the persons affected by hearing loss do not use hearing aids. The goal of this edited volume is to present a theoretically founded, interdisciplinary approach geared at understanding and improving social interaction...... impacted by hearing loss and (non-) use of hearing technologies. The researchers report on pilot studies from Australia, Denmark, Finland, Germany, Switzerland and the USA. Using Conversation Analysis, the studies identify problems and serve as points of departure for possible solutions. Researchers...

  15. The influence of hearing aids on the speech and language development of children with hearing loss.

    Science.gov (United States)

    Tomblin, J Bruce; Oleson, Jacob J; Ambrose, Sophie E; Walker, Elizabeth; Moeller, Mary Pat

    2014-05-01

    IMPORTANCE Hearing loss (HL) in children can be deleterious to their speech and language development. The standard of practice has been early provision of hearing aids (HAs) to moderate these effects; however, there have been few empirical studies evaluating the effectiveness of this practice on speech and language development among children with mild-to-severe HL. OBJECTIVE To investigate the contributions of aided hearing and duration of HA use to speech and language outcomes in children with mild-to-severe HL. DESIGN, SETTING, AND PARTICIPANTS An observational cross-sectional design was used to examine the association of aided hearing levels and length of HA use with levels of speech and language outcomes. One hundred eighty 3- and 5-year-old children with HL were recruited through records of Universal Newborn Hearing Screening and referrals from clinical service providers in the general community in 6 US states. INTERVENTIONS All but 4 children had been fitted with HAs, and measures of aided hearing and the duration of HA use were obtained. MAIN OUTCOMES AND MEASURES Standardized measures of speech and language ability were obtained. RESULTS Measures of the gain in hearing ability for speech provided by the HA were significantly correlated with levels of speech (ρ179 = 0.20; P = .008) and language: ρ155 = 0.21; P = .01) ability. These correlations were indicative of modest levels of association between aided hearing and speech and language outcomes. These benefits were found for children with mild and moderate-to-severe HL. In addition, the amount of benefit from aided hearing interacted with the duration of HA experience (Speech: F4,161 = 4.98; P < .001; Language: F4,138 = 2.91; P < .02). Longer duration of HA experience was most beneficial for children who had the best aided hearing. CONCLUSIONS AND RELEVANCE The degree of improved hearing provided by HAs was associated with better speech and language development in children

  16. Capacitive Micromachined Ultrasonic Transducers (CMUTs for Underwater Imaging Applications

    Directory of Open Access Journals (Sweden)

    Jinlong Song

    2015-09-01

    Full Text Available A capacitive micromachined ultrasonic transducer structure for use in underwater imaging is designed, fabricated and tested in this paper. In this structure, a silicon dioxide insulation layer is inserted between the top electrodes and the vibration membrane to prevent ohmic contact. The capacitance-voltage (C-V characteristic curve shows that the transducer offers suitable levels of hysteresis and repeatability performance. The −6 dB center frequency is 540 kHz and the transducer has a bandwidth of 840 kHz for a relative bandwidth of 155%. Underwater pressure of 143.43 Pa is achieved 1 m away from the capacitive micromachined ultrasonic transducer under 20  excitation. Two-dimensional underwater ultrasonic imaging, which is able to prove that a rectangular object is present underwater, is achieved. The results presented here indicate that our work will be highly beneficial for the establishment of an underwater ultrasonic imaging system.

  17. Underwater Sensor Network Redeployment Algorithm Based on Wolf Search.

    Science.gov (United States)

    Jiang, Peng; Feng, Yang; Wu, Feng

    2016-10-21

    This study addresses the optimization of node redeployment coverage in underwater wireless sensor networks. Given that nodes could easily become invalid under a poor environment and the large scale of underwater wireless sensor networks, an underwater sensor network redeployment algorithm was developed based on wolf search. This study is to apply the wolf search algorithm combined with crowded degree control in the deployment of underwater wireless sensor networks. The proposed algorithm uses nodes to ensure coverage of the events, and it avoids the prematurity of the nodes. The algorithm has good coverage effects. In addition, considering that obstacles exist in the underwater environment, nodes are prevented from being invalid by imitating the mechanism of avoiding predators. Thus, the energy consumption of the network is reduced. Comparative analysis shows that the algorithm is simple and effective in wireless sensor network deployment. Compared with the optimized artificial fish swarm algorithm, the proposed algorithm exhibits advantages in network coverage, energy conservation, and obstacle avoidance.

  18. Design and implementation of an underwater sound recording device

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jayson J.; Myers, Joshua R.; Carlson, Thomas J.; Deng, Zhiqun; Rohrer, John S.; Caviggia, Kurt A.

    2011-09-19

    The purpose of this study was to design and build two versions of an underwater sound recording device. The device designed is referred to as the Underwater Sound Recorder (USR), which can be connected to one or two hydrophones or other underwater sound sensors. The URS contains a 26 dB preamplifier and a user selectable gain that permits additional amplification of input to the system from 26 dB to 46 dB. Signals within the frequency range up to 15 kHz may be recorded using the USR. Examples of USR applications are monitoring underwater processes that have the potential to create large pressure waves that could potentially harm fish or other aquatic life, such as underwater explosions or pile driving. Additional applications are recording sound generated by vessels or the vocalizations of some marine mammals, such as the calls from many species of whales.

  19. A man-made object detection for underwater TV

    Science.gov (United States)

    Cheng, Binbin; Wang, Wenwu; Chen, Yao

    2018-03-01

    It is a great challenging task to complete an automatic search of objects underwater. Usually the forward looking sonar is used to find the target, and then the initial identification of the target is completed by the side-scan sonar, and finally the confirmation of the target is accomplished by underwater TV. This paper presents an efficient method for automatic extraction of man-made sensitive targets in underwater TV. Firstly, the image of underwater TV is simplified with taking full advantage of the prior knowledge of the target and the background; then template matching technology is used for target detection; finally the target is confirmed by extracting parallel lines on the target contour. The algorithm is formulated for real-time execution on limited-memory commercial-of-the-shelf platforms and is capable of detection objects in underwater TV.

  20. Underwater welding using remote controlled robots. Development of remote underwater welding technology with a high power YAG laser

    International Nuclear Information System (INIS)

    Miwa, Yasuhiro; Sato, Syuuichi; Kojima, Toshio; Owaki, Katsura; Hirose, Naoya

    2002-01-01

    As components in nuclear power plant have been periodically carried out their inspection and repair to keep their integrity, on radioactive liquid wastes storage facility, because of difficulty on their inspection by human beings, some are remained without inspection, and even when capable of inspection, conversion from human works to remote operations is desired from a viewpoint of their operation efficiency upgrading. For response to these needs, some developments on a technology capable of carrying out inspection of their inside at underwater environment and repairing welding with YAG laser by means of remote operation, have been performed. Remote underwater inspection and repair technology is a combination technology of already applied underwater mobile technique (underwater inspection robot) with underwater YAG laser welding technique which is recently at actual using level. Therefore, this technology is composed of an inspection robot and a repair welding robot. And, testing results using the underwater inspection robot and welding test results using the underwater repair welding robot, were enough preferable to obtain forecasting applicable to actual apparatuses. This technology is especially effective for inspection and repair of inside of nuclear fuel cycle apparatuses and relatively high dose apparatuses, and can be thought to be applicable also to large capacity tanks, tanks dealing with harmful matters, underwater structures, and so on, in general industries. (G.K.)

  1. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

    This is the first book on explosion-generated water waves. It presents the theoretical foundations and experimental results of the generation and propagation of impulsively generated waves resulting from underwater explosions. Many of the theories and concepts presented herein are applicable to other types of water waves, in particular, tsunamis and waves generated by the fall of a meteorite. Linear and nonlinear theories, as well as experimental calibrations, are presented for cases of deep and shallow water explosions. Propagation of transient waves on dissipative, nonuniform bathymetries to

  2. Hemispherical optical dome for underwater communication

    Science.gov (United States)

    Shiri, Ron S.; Lunde, Emily L.; Coronado, Patrick L.; Quijada, Manuel A.

    2017-08-01

    For many years, acoustic systems have been used as the primary method for underwater communication; however, the data transfer rate of such systems is low because sound propagates slowly through water. A higher throughput can be achieved using visible light to transmit data underwater. The first issue with this approach is that there is generally a large loss of the light signal due to scattering and absorption in water, even though there is an optimal wavelength for transmission in the blue or green wavelengths of the visible spectrum. The second issue is that a simple communication system, consisting only of a highly directional source/transmitter and small optical detector/receiver, has a very narrow field of view. The goal of this project is to improve an optical, underwater communication system by increasing the effective field of view of the receiving optics. To this end, we make two changes to the simple system: (1) An optical dome was added near the receiver. An array of lenses is placed radially on the surface of the dome, reminiscent of the compound eye of an insect. The lenses make the source and detector planes conjugate, and each lens adds a new region of the source plane to the instrument's total field of view. (2) The receiver was expanded to include multiple photodiodes. With these two changes, the receiver has much more tolerance to misalignments (in position and angle) of the transmitter. Two versions of the optical dome (with 6" and 8" diameters) were designed using PTC's Creo CAD software and modeled using Synopsys' CODE V optical design software. A series of these transparent hemispherical domes, with both design diameters, were manufactured using a 5-axis mill. The prototype was then retrofitted with lenses and compared with the computer-generated model to demonstrate the effectiveness of this solution. This work shows that the dome design improves the optical field of view of the underwater communication system considerably. Furthermore, with

  3. Underwater Sound Propagation from Marine Pile Driving.

    Science.gov (United States)

    Reyff, James A

    2016-01-01

    Pile driving occurs in a variety of nearshore environments that typically have very shallow-water depths. The propagation of pile-driving sound in water is complex, where sound is directly radiated from the pile as well as through the ground substrate. Piles driven in the ground near water bodies can produce considerable underwater sound energy. This paper presents examples of sound propagation through shallow-water environments. Some of these examples illustrate the substantial variation in sound amplitude over time that can be critical to understand when computing an acoustic-based safety zone for aquatic species.

  4. Radon dynamics in underwater thermal radon therapy

    International Nuclear Information System (INIS)

    Lettner, H.; Hofmann, W.; Winkler, R.; Rolle, R.; Foisner, W.

    1998-01-01

    At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

  5. Navigation System Fault Diagnosis for Underwater Vehicle

    DEFF Research Database (Denmark)

    Falkenberg, Thomas; Gregersen, Rene Tavs; Blanke, Mogens

    2014-01-01

    This paper demonstrates fault diagnosis on unmanned underwater vehicles (UUV) based on analysis of structure of the nonlinear dynamics. Residuals are generated using dierent approaches in structural analysis followed by statistical change detection. Hypothesis testing thresholds are made signal...... based to cope with non-ideal properties seen in real data. Detection of both sensor and thruster failures are demonstrated. Isolation is performed using the residual signature of detected faults and the change detection algorithm is used to assess severity of faults by estimating their magnitude...

  6. Adaptive Target Tracking for Underwater Maneuvering Targets.

    Science.gov (United States)

    1979-12-01

    concenetrate on the bearings-only approach. In this method the Observer monitors his bearing to the Source, over a period of time. Usually the Observer must...developed in [ 5] was earlier applied with much success to tracking maneuvering air targets. This approach will now be applied in the underwater environment...April 1977. [11] A. H. Jazwinski, Stochastic Processes and Filtering Theory, Academic Press, New York, 1970. [12] D. H. Halliday, and R. Resnick, Physics, John Wiley & Sons, Inc., New York, 1966. hI

  7. [Effect of rehabilitation for prelingual deaf children who use cochlear implants in conjunction with hearing aids in the opposite ears].

    Science.gov (United States)

    Tian, Yanjing; Zhou, Huifang; Zhang, Jing; Yang, Dong; Xu, Yi; Guo, Yuxi

    2012-10-01

    To compare the effect of rehabilitation of prelingual deaf children who used a cochlear implant (CI) in one ear and a hearing aids in the opposite ear while the hearing level of the opposite ears are different. Hearing ability, language ability and learning ability was included in the content. The aim of this research is to investigate better style of rehabilitation, and to offer the best help to the prelingual deaf children. Accord ing to the hearing level of the ear opposite to the one wearing a cochlear implant and whether the opposite ear wear a hearing aid or not, 30 prelingual deaf children were divided into three groups, including cochlear implant with opposite severe hearing loss and hearing aid ear (CI+SHA), cochlear implant with opposite profound hearing loss and hearing aid ear (CI+PHA), cochlear implant only (CI). The effect of rehabilitation was assessed in six different times (3,6,9,12,15 and 18 months after the cochlear implants and hearing aids began to work). The longer time the rehabilitation spends, the better the hearing ability,language ability and the learning ability were. The hearing ability of CI+SHA was better than those of CI+PHA (Pdeaf children should take much more time on rehabilitation. The effect of rehabilitation for prelingual deaf children who used cochlear implant in one ear and hearing aid in the other depend on the residual hearing level of the other ear. If a prelingual deaf children still has any residual hearing level in the ear opposite to the cochlear implant ear, it is better for him/her to wear a hearing aid in the ear.

  8. 46 CFR 115.650 - Alternative Hull Examination (AHE) Program options: Divers or underwater ROV.

    Science.gov (United States)

    2010-10-01

    ...: Divers or underwater ROV. 115.650 Section 115.650 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Alternative Hull Examination (AHE) Program options: Divers or underwater ROV. To complete your underwater survey, you may use divers or an underwater remotely operated vehicle (ROV). (a) If you use divers to...

  9. Deafness and motor abilities level

    Directory of Open Access Journals (Sweden)

    A Zwierzchowska

    2008-09-01

    Full Text Available The audition injury hinders some motor motions and the organised coordination at the higher level and may be a cause of disturbances and disorder in some motor abilities adoption. It was assumed that deafness including its aetiology and injury mechanism may significantly influence the motor development of human being. The study aimed in checking if the deafness, as a result of various unfavourable factors, determines the motor development of children and youngsters. Consequently the dependency between qualitative features i.e.: signed motor level and aetiology, audition injury mechanism and the deafness degree was examined. The mechanism and aetiology of hearing correlated with the motor abilities displayed statistically significant dependencies in few motor trials only. Revealed correlations regarded mostly the coordination trials excluding the flexibility one. Statistically significant dependencies between the audition diminution and the motor abilities level were not found.

  10. Music and Hearing Aids

    Science.gov (United States)

    Moore, Brian C. J.

    2014-01-01

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. PMID:25361601

  11. Music and Hearing Aids

    Directory of Open Access Journals (Sweden)

    Sara M. K. Madsen

    2014-10-01

    Full Text Available The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  12. Music and hearing aids.

    Science.gov (United States)

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems. © The Author(s) 2014.

  13. Underwater pipeline impact localization using piezoceramic transducers

    Science.gov (United States)

    Zhu, Junxiao; Ho, Siu Chun Michael; Patil, Devendra; Wang, Ning; Hirsch, Rachel; Song, Gangbing

    2017-10-01

    Reports indicated that impact events accounted for 47% of offshore pipeline failures, which calls for impact detection and localization for subsea pipelines. In this paper, an innovative method for rapid localization of impacts on underwater pipelines utilizing a novel determination technique for both arrival-time and group velocity (ATGV) of ultrasonic guided waves with lead zirconate titanate (PZT) transducers is described. PZT transducers mounted on the outer surface of a model pipeline were utilized to measure ultrasonic guided waves generated by impact events. Based on the signals from PZT sensors, the ATGV technique integrates wavelet decomposition, Hilbert transform and statistical analysis to pinpoint the arrival-time of the designated ultrasonic guided waves with a specific group velocity. Experimental results have verified the effectiveness and the localization accuracy for eight impact points along a model underwater pipeline. All estimations errors were small and were comparable with the wavelength of the designated ultrasonic guided waves. Furthermore, the method is robust against the low frequency structural vibration introduced by other external forces.

  14. GAS FLOW IN UNDERWATER BREATHING INSTALLATIONS

    Directory of Open Access Journals (Sweden)

    Anca CONSTANTIN

    2017-11-01

    Full Text Available The open circuit underwater breathing apparatus can be a one or two-stage regulator used in scuba diving or a two-stage regulator used in surface supplied installations. These installations are proper in underwater sites at small depth. The pneumatic circuit of a two-stage regulator is composed mainly of a first stage regulator mounted on the air cylinders and a second stage carried by the diver in his mouth. The two regulators are linked together by a medium pressure hose. The circuit opens when the depression created by the diver’s inhalation, in the second stage body, reaches a certain value. The second stage opening causes a transient movement, namely an expansion wave that propagates through the medium pressure hose to the first stage regulator. The first stage regulator opens and the air in the cylinders is allowed to flow to the diver. The longer the hose, the greater the duration of the expansion wave propagation. Investigations on the wave propagation offer data on the inspiration unsteady motion duration which influences the respiratory effort of the diver.

  15. Hydrogel microphones for stealthy underwater listening

    Science.gov (United States)

    Gao, Yang; Song, Jingfeng; Li, Shumin; Elowsky, Christian; Zhou, You; Ducharme, Stephen; Chen, Yong Mei; Zhou, Qin; Tan, Li

    2016-08-01

    Exploring the abundant resources in the ocean requires underwater acoustic detectors with a high-sensitivity reception of low-frequency sound from greater distances and zero reflections. Here we address both challenges by integrating an easily deformable network of metal nanoparticles in a hydrogel matrix for use as a cavity-free microphone. Since metal nanoparticles can be densely implanted as inclusions, and can even be arranged in coherent arrays, this microphone can detect static loads and air breezes from different angles, as well as underwater acoustic signals from 20 Hz to 3 kHz at amplitudes as low as 4 Pa. Unlike dielectric capacitors or cavity-based microphones that respond to stimuli by deforming the device in thickness directions, this hydrogel device responds with a transient modulation of electric double layers, resulting in an extraordinary sensitivity (217 nF kPa-1 or 24 μC N-1 at a bias of 1.0 V) without using any signal amplification tools.

  16. Hybrid Underwater Vehicle: ARV Design and Development

    Directory of Open Access Journals (Sweden)

    Zhigang DENG

    2014-02-01

    Full Text Available The development of SMU-I, a new autonomous & remotely-operated vehicle (ARV is described. Since it has both the characteristics of autonomous underwater vehicle (AUV and remote operated underwater vehicle (ROV, it is able to achieve precision fix station operation and manual timely intervention. In the paper the initial design of basic components, such as vehicle, propulsion, batteries etc. and the control design of motion are introduced and analyzed. ROV’s conventional cable is replaced by a fiber optic cable, which makes it available for high-bandwidth real-time video, data telemetry and high-quality teleoperation. Furthermore, with the aid of the manual real-time remote operation and ranging sonar, it also resolves the AUV’s conflicting issue, which can absolutely adapt the actual complex sea environment and satisfy the unknown mission need. The whole battery system is designed as two-battery banks, whose voltages and temperatures are monitored through CAN (controller area network bus to avoid battery fire and explosion. A fuzzy-PID controller is designed for its motion control, including depth control and direction control. The controller synthesizes the advantage of fuzzy control and PID control, utilizes the fuzzy rules to on-line tune the parameters of PID controller, and achieves a better control effect. Experiment results demonstrate to show the effectiveness of the test-bed.

  17. Software architecture of biomimetic underwater vehicle

    Science.gov (United States)

    Praczyk, Tomasz; Szymak, Piotr

    2016-05-01

    Autonomous underwater vehicles are vehicles that are entirely or partly independent of human decisions. In order to obtain operational independence, the vehicles have to be equipped with a specialized software. The main task of the software is to move the vehicle along a trajectory with collision avoidance. Moreover, the software has also to manage different devices installed on the vehicle board, e.g. to start and stop cameras, sonars etc. In addition to the software embedded on the vehicle board, the software responsible for managing the vehicle by the operator is also necessary. Its task is to define mission of the vehicle, to start, to stop the mission, to send emergency commands, to monitor vehicle parameters, and to control the vehicle in remotely operated mode. An important objective of the software is also to support development and tests of other software components. To this end, a simulation environment is necessary, i.e. simulation model of the vehicle and all its key devices, the model of the sea environment, and the software to visualize behavior of the vehicle. The paper presents architecture of the software designed for biomimetic autonomous underwater vehicle (BAUV) that is being constructed within the framework of the scientific project financed by Polish National Center of Research and Development.

  18. STABILITY OF UNDERWATER STRUCTURE UNDER WAVE ATTACK

    Directory of Open Access Journals (Sweden)

    C. Paotonan

    2012-02-01

    Full Text Available Geotube is, among others, a type of coastal structure that is increasingly accepted for coastal protection especially underwater breakwater. Besides its relatively low cost, it has other advantages such as flexibility, ease of construction and the fact that it can be filled with local sand material. Similar to all other coastal structures, it should also be stable under wave attack. A simple theoretical approach based on linear wave was adopted to estimate the stability of such structure. The theoretical solution was then compared with an experimental study. The experimental study was conducted at the Hydraulics and Hydrology Laboratory of Universitas Gadjah Mada. However, instead of a real geotube, PVC pipe was used where the weight of the PVC was varied by adjusting the volume of sand in the pipe. The result indicated that the agreement between the theoretical solution and the experiment was encouraging. The analytical solution may be utilized to predict underwater pipe stability under wave attack with certain degree of accuracy.

  19. Underwater noise levels in UK waters.

    Science.gov (United States)

    Merchant, Nathan D; Brookes, Kate L; Faulkner, Rebecca C; Bicknell, Anthony W J; Godley, Brendan J; Witt, Matthew J

    2016-11-10

    Underwater noise from human activities appears to be rising, with ramifications for acoustically sensitive marine organisms and the functioning of marine ecosystems. Policymakers are beginning to address the risk of ecological impact, but are constrained by a lack of data on current and historic noise levels. Here, we present the first nationally coordinated effort to quantify underwater noise levels, in support of UK policy objectives under the EU Marine Strategy Framework Directive (MSFD). Field measurements were made during 2013-2014 at twelve sites around the UK. Median noise levels ranged from 81.5-95.5 dB re 1 μPa for one-third octave bands from 63-500 Hz. Noise exposure varied considerably, with little anthropogenic influence at the Celtic Sea site, to several North Sea sites with persistent vessel noise. Comparison of acoustic metrics found that the RMS level (conventionally used to represent the mean) was highly skewed by outliers, exceeding the 97 th percentile at some frequencies. We conclude that environmental indicators of anthropogenic noise should instead use percentiles, to ensure statistical robustness. Power analysis indicated that at least three decades of continuous monitoring would be required to detect trends of similar magnitude to historic rises in noise levels observed in the Northeast Pacific.

  20. Underwater Wireless Acousto-Optic Waveguide (UWAOW)

    Science.gov (United States)

    Giuliano, Giovanni; Kent, Lionel W. J.; Laycock, Leslie C.

    2017-10-01

    The present study originated in the lack of research into achieving underwater total internal reflection (TIR) via the acousto-optic effect. The uniqueness of this technique exists in the fact that it is based on a high sound pressure level which induces a localised change in refractive index of seawater sufficient to achieve total internal reflection within the communication channel. Different transducer systems for generating the pressure wave have been investigated and take the form of a wave which may be either a standing wave, or a novel beamforming technique. The former is based on an array of transducers and with an acoustic mirror at the receiver in order to establish the standing wave. The alternative approach relies on the high intrinsic directionality of a novel beamformer where an annular transducer array is examined as an acoustic source. In this paper, the main characteristics of the acoustic optic waveguide will be presented. This will include both sound and light propagation in the ocean, TIR, novel beam propagation, the refractive index of water as a function of the externally applied acoustic pressure, and the acoustic technology. The modelled results, the limitations imposed by the challenging medium, and the system requirements required to obtain an Underwater Wireless Acousto-Optic Waveguide (UWAOW) will be also addressed.

  1. Using Autonomous Underwater Vehicles as Sensor Platforms for Ice-Monitoring

    OpenAIRE

    Norgren, Petter; Skjetne, Roger

    2014-01-01

    Due to the receding sea-ice extent in the Arctic, and the potentially large undiscovered petroleum resources present north of the Arctic circle, offshore activities in ice-infested waters are increasing. Due to the presence of drifting sea-ice and icebergs, ice management (IM) becomes an important part of the offshore operation, and an important part of an IM system is the ability to reliably monitor the ice conditions. An autonomous underwater vehicle (AUV) has a unique capability of high un...

  2. Impact of Vessel Noise on Oyster Toadfish (Opsanus tau) Behavior and Implications for Underwater Noise Management

    Science.gov (United States)

    Krahforst, Cecilia S.

    Underwater noise and its impacts on marine life are growing management concerns. This dissertation considers both the ecological and social concerns of underwater noise, using the oyster toadfish (Opsanus tau) as a model species. Oyster toadfish call for mates using a boatwhistle sound, but increased ambient noise levels from vessels or other anthropogenic activities are likely to influence the ability of males to find mates. If increased ambient noise levels reduce fish fitness then underwater noise can impact socially valued ecosystem services (e.g. fisheries). The following ecological objectives of the impacts of underwater noise on oyster toadfish were investigated: (1) to determine how noise influences male calling behavior; (2) to assess how areas of high vessel activity ("noisy") and low vessel activity ("quiet") influence habitat utilization (fish standard length and occupancy rate); and (3) to discover if fitness (number of clutches and number of embryos per clutch) is lower in "noisy" compared with "quiet" sites. Field experiments were executed in "noisy" and "quiet" areas. Recorded calls by males in response to playback sounds (vessel, predator, and snapping shrimp sounds) and egg deposition by females ("noisy" vs. "quiet" sites) demonstrated that oyster toadfish are impacted by underwater noise. First, males decreased their call rates and called louder in response to increased ambient noise levels. Second, oyster toadfish selected nesting sites in areas with little or no inboard motorboat activity. Third, male oyster toadfish at "noisy" sites either had no egg clutches on their shelters or the number of embryos per clutch was significantly lower than in the "quiet" areas. Underwater noise and disturbance from vessels are influencing the fitness of the oyster toadfish. The social significance of the growing concerns regarding underwater noise was investigated by identifying dominant themes found within two types of texts: four recent underwater noise

  3. A Speed Control Method for Underwater Vehicle under Hydraulic Flexible Traction

    OpenAIRE

    Zhao, Yin; Xia, Ying-kai; Chen, Ying; Xu, Guo-Hua

    2015-01-01

    Underwater vehicle speed control methodology method is the focus of research in this study. Driven by a hydraulic flexible traction system, the underwater vehicle advances steadily on underwater guide rails, simulating an underwater environment for the carried device. Considering the influence of steel rope viscoelasticity and the control system traction structure feature, a mathematical model of the underwater vehicle driven by hydraulic flexible traction system is established. A speed contr...

  4. Underwater television camera for monitoring inner side of pressure vessel

    International Nuclear Information System (INIS)

    Takayama, Kazuhiko.

    1997-01-01

    An underwater television support device equipped with a rotatable and vertically movable underwater television camera and an underwater television camera controlling device for monitoring images of the inside of the reactor core photographed by the underwater television camera to control the position of the underwater television camera and the underwater light are disposed on an upper lattice plate of a reactor pressure vessel. Both of them are electrically connected with each other by way of a cable to rapidly observe the inside of the reactor core by the underwater television camera. The reproducibility is extremely satisfactory by efficiently concentrating the position of the camera and image information upon inspection and observation. As a result, the steps for periodical inspection can be reduced to shorten the days for the periodical inspection. Since there is no requirement to withdraw fuel assemblies over a wide reactor core region, and the device can be used with the fuel assemblies being left as they are in the reactor, it is suitable for inspection of detectors for nuclear instrumentation. (N.H.)

  5. Underwater fiber-wireless communication with a passive front end

    Science.gov (United States)

    Xu, Jing; Sun, Bin; Lyu, Weichao; Kong, Meiwei; Sarwar, Rohail; Han, Jun; Zhang, Wei; Deng, Ning

    2017-11-01

    We propose and experimentally demonstrate a novel concept on underwater fiber-wireless (Fi-Wi) communication system with a fully passive wireless front end. A low-cost step-index (SI) plastic optical fiber (POF) together with a passive collimating lens at the front end composes the underwater Fi-Wi architecture. We have achieved a 1.71-Gb/s transmission at a mean BER of 4.97 × 10-3 (1.30 × 10-3 when using power loading) over a 50-m SI-POF and 2-m underwater wireless channel using orthogonal frequency division multiplexing (OFDM). Although the wireless part is very short, it actually plays a crucial role in practical underwater implementation, especially in deep sea. Compared with the wired solution (e.g. using a 52-m POF cable without the UWOC part), the proposed underwater Fi-Wi scheme can save optical wet-mate connectors that are sophisticated, very expensive and difficult to install in deep ocean. By combining high-capacity robust POF with the mobility and ubiquity of underwater wireless optical communication (UWOC), the proposed underwater Fi-Wi technology will find wide application in ocean exploration.

  6. Towards a Hybrid Approach to Context Reasoning for Underwater Robots

    Directory of Open Access Journals (Sweden)

    Xin Li

    2017-02-01

    Full Text Available Ontologies have been widely used to facilitate semantic interoperability and serve as a common information model in many applications or domains. The Smart and Networking Underwater Robots in Cooperation Meshes (SWARMs project, aiming to facilitate coordination and cooperation between heterogeneous underwater vehicles, also adopts ontologies to formalize information that is necessarily exchanged between vehicles. However, how to derive more useful contexts based on ontologies still remains a challenge. In particular, the extreme nature of the underwater environment introduces uncertainties in context data, thus imposing more difficulties in context reasoning. None of the existing context reasoning methods could individually deal with all intricacies in the underwater robot field. To this end, this paper presents the first proposal applying a hybrid context reasoning mechanism that includes ontological, rule-based, and Multi-Entity Bayesian Network (MEBN reasoning methods to reason about contexts and their uncertainties in the underwater robot field. The theoretical foundation of applying this reasoning mechanism in underwater robots is given by a case study on the oil spill monitoring. The simulated reasoning results are useful for further decision-making by operators or robots and they show that the consolidation of different reasoning methods is a promising approach for context reasoning in underwater robots.

  7. How to quantify binaural hearing in patients with unilateral hearing using hearing implants

    NARCIS (Netherlands)

    Snik, A.F.M.; Agterberg, M.J.H.; Bosman, A.

    2015-01-01

    Application of bilateral hearing devices in bilateral hearing loss and unilateral application in unilateral hearing loss (second ear with normal hearing) does not a priori lead to binaural hearing. An overview is presented on several measures of binaural benefits that have been used in patients with

  8. Terrain aided navigation for autonomous underwater vehicles with coarse maps

    International Nuclear Information System (INIS)

    Zhou, Ling; Cheng, Xianghong; Zhu, Yixian

    2016-01-01

    Terrain aided navigation (TAN) is a form of geophysical localization technique for autonomous underwater vehicles (AUVs) operating in GPS-denied environments. TAN performance on sensor-rich AUVs has been evaluated in sea trials. However, many challenges remain before TAN can be successfully implemented on sensor-limited AUVs, especially with coarse maps. To improve TAN performance over coarse maps, a Gaussian process (GP) is proposed for the modeling of bathymetric terrain and integrated into the particle filter (GP-PF). GP is applied to provide not only the bathymetric value prediction through learning a set of bathymetric data from coarse maps but also the variance of the prediction. As a measurement update, calculated on bathymetric deviation is performed through the PF to obtain absolute and bounded positioning accuracy. Through the analysis of TAN performance on experimental data for two different terrains with map resolutions of 10–50 m, both the ability of the proposed model to represent the actual bathymetric terrain with accuracy and the effect of the GP-PF for TAN on sensor-limited systems in suited terrain are demonstrated. The experiment results further verify that there is an inverse relationship between the coarseness of the map and the overall TAN accuracy in rough terrains, but there is hardly any relationship between them in relatively flat terrains. (paper)

  9. Hearing aid adjustment

    DEFF Research Database (Denmark)

    Heinemann, Trine; Matthews, Ben; Raudaskoski, Pirkko

    2012-01-01

    to the interaction during hearing aid fitting. This report of a Danish pilot study describes two such problems. The first problem arises from the requirement that the audiologist needs to ‘translate’ the patient’s subjective hearing description for making technological decisions. The second problem is the way...... in which the hearing aid user’s implicit and often unrealistic expectations are handled. This kind of research has potential application for developing a model of best practices....

  10. A Secure Communication Suite for Underwater Acoustic Sensor Networks

    Directory of Open Access Journals (Sweden)

    Angelica Lo Duca

    2012-11-01

    Full Text Available In this paper we describe a security suite for Underwater Acoustic Sensor Networks comprising both fixed and mobile nodes. The security suite is composed of a secure routing protocol and a set of cryptographic primitives aimed at protecting the confidentiality and the integrity of underwater communication while taking into account the unique characteristics and constraints of the acoustic channel. By means of experiments and simulations based on real data, we show that the suite is suitable for an underwater networking environment as it introduces limited, and sometimes negligible, communication and power consumption overhead.

  11. Application of YAG laser processing in underwater welding and cutting

    International Nuclear Information System (INIS)

    Ohwaki, Katsura; Morita, Ichiro; Kojima, Toshio; Sato, Shuichi

    2002-01-01

    The high-power YAG laser is a new fabrication tool. The laser torch is easy to combine with complex with complex mechanics because of beam delivery through optical fiber. A direct underwater laser welding technology has been developed and applied to the preservation, maintenance and removal of nuclear power plants. For subdividing or removing operations for retirement of plants, the laser cutting properties were confirmed to allow a maximum cutting thickness of 80 mm. For repairing inner surface of stainless steel tanks, an underwater laser welding system using a remote-controlled robot was developed and the high quality of underwater laser welding was confirmed. (author)

  12. Centralised versus Decentralised Control Reconfiguration for Collaborating Underwater Robots

    DEFF Research Database (Denmark)

    Furno, Lidia; Nielsen, Mikkel Cornelius; Blanke, Mogens

    2015-01-01

    The present paper introduces an approach to fault-tolerant reconfiguration for collaborating underwater robots. Fault-tolerant reconfiguration is obtained using the virtual actuator approach, Steen (2005). The paper investigates properties of a centralised versus a decentralised implementation...... an underwater drill needs to be transported and positioned by three collaborating robots as part of an underwater autonomous operation....... and assesses the capabilities under communication constraints between the individual robots. In the centralised case, each robot sends information related to its own status to a unique virtual actuator that computes the necessary reconfiguration. In the decentralised case, each robot is equipped with its own...

  13. Adaptive Decentralized Control of Mobile Underwater Sensor Networks and Robots for Modeling Underwater Phenomena

    Directory of Open Access Journals (Sweden)

    Carrick Detweiler

    2014-05-01

    Full Text Available Understanding the dynamics of bodies of water and their impact on the global environment requires sensing information over the full volume of water. In this article, we develop a gradient-based decentralized controller that dynamically adjusts the depth of a network of underwater sensors to optimize sensing for computing maximally detailed volumetric models. We prove that the controller converges to a local minimum and show how the controller can be extended to work with hybrid robot and sensor network systems. We implement the controller on an underwater sensor network with depth adjustment capabilities. Through simulations and in-situ experiments, we verify the functionality and performance of the system and algorithm.

  14. Age-Related Hearing Loss

    Science.gov (United States)

    ... hearing loss. Here are the most common ones: Styles of hearing aids Source: NIH/NIDCD Hearing aids ... information, contact us at: NIDCD Information Clearinghouse 1 Communication Avenue Bethesda, MD 20892-3456 Toll-free voice: ( ...

  15. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Noise-Induced Hearing Loss On this page: What is ... I find additional information about NIHL? What is noise-induced hearing loss? Every day, we experience sound ...

  16. Global Hearing Loss Prevention.

    Science.gov (United States)

    Brown, Clifford Scott; Emmett, Susan D; Robler, Samantha Kleindienst; Tucci, Debara L

    2018-03-07

    Hearing loss is the fourth leading contributor to years lived with a disability worldwide. Most recent estimates indicate that one-half of a billion people suffer from disabling hearing loss worldwide. The social and economic burden is significant. When attributing monetary value to years lived with disability owing to hearing loss, there is greater than $US750 billion lost each year globally. There are numerous contributors to hearing loss, including congenital, infectious, noise exposure, age-related, traumatic, and immune-mediated causes. Understanding the pathophysiology of these factors allows for the development of preventative and treatment strategies specific to the underlying cause. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Hearing Conservation Live #2430

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    Occupational hearing loss is one of the most common work-related illnesses in the United States (US). From 22 to 30 million US workers are exposed to hazardous noise levels at work, and 25% of these workers will develop permanent hearing loss. Hearing loss from noise is slow and painless, and you can have a disability before you notice it. This course presents the hazards associated with workplace noise, the purpose and elements of the Los Alamos National Laboratory (LANL) Hearing Conservation Program (HCP), and controls that are available to reduce your exposure to hazardous levels of noise.

  18. International hearing protector standardization

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2002-01-01

    Hearing protectors shall fulfill some minimum requirements to their performance. As hearing protector manufacturers sell the products all over the world, the testing and certification of hearing protectors has become an international issue. The ISO working group WG17 under the headlines Acoustics......, Noise, produce hearing protector standards to be used at an international level. The presentation will cover the ongoing work in WG17, including the revision of existing standards (ISO 4869-1, ISO 4869-3), upcoming new standards (ISO 4869-7) and the plans and status for future standards (performance...

  19. Comparison of Different Levels of Reading Comprehension between Hearing-Impaired Loss and Normal-Hearing Students

    Directory of Open Access Journals (Sweden)

    Azam Sharifi

    2011-12-01

    Full Text Available Background and Aim: Reading skill is one of the most important necessities of students' learning in everyday life. This skill is referred to the ability of comprehension, comment and conclusion from texts and receiving the meaning of the massage which is composed. Educational development in any student has a direct relation with the ability of the comprehension. This study is designed to investigate the effects of hearing loss on reading comprehension in hearing-impaired students compared to normal-hearing ones.Methods: Seventeen hearing-impaired students in 4th year of primary exceptional schools in Karaj, Robatkarim and Shahriyar, Iran, were enrolled in this cross-sectional study. Seventeen normal-hearing students were randomly selected from ordinary schools next to exceptional ones as control group. They were compared for different levels of reading comprehension using the international standard booklet (PIRLS 2001. Results: There was a significant difference in performance between hearing-impaired and normal- hearing students in different levels of reading comprehension (p<0.05.Conclusion: Hearing loss has negative effects on different levels of reading comprehension, so in exceptional centers, reconsideration in educational planning in order to direct education from memorizing to comprehension and deeper layers of learning seems necessary.

  20. Task Allocation and Path Planning for Collaborative Autonomous Underwater Vehicles Operating through an Underwater Acoustic Network

    Directory of Open Access Journals (Sweden)

    Yueyue Deng

    2013-01-01

    Full Text Available Dynamic and unstructured multiple cooperative autonomous underwater vehicle (AUV missions are highly complex operations, and task allocation and path planning are made significantly more challenging under realistic underwater acoustic communication constraints. This paper presents a solution for the task allocation and path planning for multiple AUVs under marginal acoustic communication conditions: a location-aided task allocation framework (LAAF algorithm for multitarget task assignment and the grid-based multiobjective optimal programming (GMOOP mathematical model for finding an optimal vehicle command decision given a set of objectives and constraints. Both the LAAF and GMOOP algorithms are well suited in poor acoustic network condition and dynamic environment. Our research is based on an existing mobile ad hoc network underwater acoustic simulator and blind flooding routing protocol. Simulation results demonstrate that the location-aided auction strategy performs significantly better than the well-accepted auction algorithm developed by Bertsekas in terms of task-allocation time and network bandwidth consumption. We also demonstrate that the GMOOP path-planning technique provides an efficient method for executing multiobjective tasks by cooperative agents with limited communication capabilities. This is in contrast to existing multiobjective action selection methods that are limited to networks where constant, reliable communication is assumed to be available.

  1. Outcomes of Bone Anchored Hearing Aids (BAHA) for Single Sided Deafness in Nontraditional Candidates.

    Science.gov (United States)

    Schwartz, Seth R; Kobylk, Deborah

    2016-12-01

    To assess both quality of life (QOL) and hearing outcomes in bone anchored hearing aid (BAHA) users for single sided deafness with 1) less than total hearing loss in the deaf ear, or 2) some degree of hearing loss in the better ear and compare them to traditional candidates. Prospective comparative cohort study. Tertiary referral center. Patients with a BAHA for single sided deafness were assigned into groups based on hearing thresholds in the deaf ear (> or or hearing including Quick SIN and HINT in quiet and noise, and a localization task. Differences in QOL, hearing performance in noise, and localization ability. Nineteen patients were tested. Patients with residual hearing in the BAHA ear showed nonsignificant trends toward improved performance in noise localization compared with those without residual hearing. There were no statistically significant differences in QOL between groups. Patients with hearing loss in the control ear had equivalent QOL scores to those with normal hearing in the control ear despite performing worse on speech in noise tasks. BAHA patients with hearing loss in the better ear seem to perform worse in noise relative to those without but have equivalent perceived benefit. Residual hearing in the implanted ear may improve performance. A larger sample size is needed to confirm these trends.

  2. Status of the ANTARES underwater neutrino telescope

    CERN Document Server

    Hallewell, G D

    2003-01-01

    The ANTARES Collaboration is constructing a deep underwater neutrino detector for operation at -2400 m off the French Mediterranean coast near Toulon. The detector, which will begin operation in 2004, will have an aperture of approx 0.1 km sup 2 , and will contain 900 photomultiplier tubes. The photomultiplier axes will be angled 45 deg. downward toward the seabed to observe the Cherenkov emissions of upward-going muons created by the interactions in or near the detector of high energy neutrinos traversing the Earth. These neutrinos arrive undeviated from a variety of galactic and extragalactic sources of astrophysical interest, and might be produced in the possible annihilation of dark matter neutralinos. The design and present status of the detector are summarized. Results from site evaluation and the development of supporting instrumentation are outlined.

  3. Transducers and arrays for underwater sound

    CERN Document Server

    Butler, John L

    2016-01-01

    This improved and updated second edition covers the theory, development, and design of electro-acoustic transducers for underwater applications. This highly regarded text discusses the basics of piezoelectric and magnetostrictive transducers that are currently being used as well as promising new designs. It presents the basic acoustics as well as the specific acoustics data needed in transducer design and evaluation. A broad range of designs of projectors and hydrophones are described in detail along with methods of modeling, evaluation, and measurement. Analysis of projector and hydrophone transducer arrays, including the effects of mutual radiation impedance and numerical models for elements and arrays, are also covered. The book includes new advances in transducer design and transducer materials and has been completely reorganized to be suitable for use as a textbook, as well as a reference or handbook. The new edition contains updates to the first edition, end-of-chapter exercises, and solutions to select...

  4. The NESTOR underwater neutrino telescope project

    Energy Technology Data Exchange (ETDEWEB)

    Rapidis, Petros A. [Institute of Nuclear Physics, National Center for Scientific Research ' Demokritos' , Athens 15310 (Greece)], E-mail: rapidis@inp.demokritos.gr

    2009-04-11

    The NESTOR collaboration is continuing its efforts towards deploying an underwater neutrino telescope. Further site studies (e.g. water light transmission measurements, sedimentation rates, etc.) are being carried out within the context of characterizing a site that may host the proposed KM3NeT infrastructure. In addition, following the successful deployment of a single floor of a NESTOR tower in 2003, five floors are now in the final stages of preparation. The use of these five floors in a form of a truncated tower together with four autonomous strings to be located some 300 m away from the tower is being contemplated. This arrangement, named NuBE (for Neutrino Burst Experiment), that may allow the detection neutrinos in coincidence with Gamma Ray Bursts, will be described.

  5. A Validation Process for Underwater Localization Algorithms

    Directory of Open Access Journals (Sweden)

    Marc Hildebrandt

    2014-09-01

    Full Text Available This paper describes the validation process of a localization algorithm for underwater vehicles. In order to develop new localization algorithms, it is essential to characterize them with regard to their accuracy, long-term stability and robustness to external sources of noise. This is only possible if a gold-standard reference localization (GSRL is available against which any new localization algorithm (NLA can be tested. This process requires a vehicle which carries all the required sensor and processing systems for both the GSRL and the NLA. This paper will show the necessity of such a validation process, briefly sketch the test vehicle and its capabilities, describe the challenges in computing the localizations of both the GSRL and the NLA simultaneously for comparison, and conclude with experimental data of real-world trials.

  6. Improved Underwater Excitation-Emission Matrix Fluorometer

    Science.gov (United States)

    Moore, Casey; daCunha, John; Rhoades, Bruce; Twardowski, Michael

    2007-01-01

    A compact, high-resolution, two-dimensional excitation-emission matrix fluorometer (EEMF) has been designed and built specifically for use in identifying and measuring the concentrations of organic compounds, including polluting hydrocarbons, in natural underwater settings. Heretofore, most EEMFs have been designed and built for installation in laboratories, where they are used to analyze the contents of samples collected in the field and brought to the laboratories. Because the present EEMF can be operated in the field, it is better suited to measurement of spatially and temporally varying concentrations of substances of interest. In excitation-emission matrix (EEM) fluorometry, fluorescence is excited by irradiating a sample at one or more wavelengths, and the fluorescent emission from the sample is measured at multiple wavelengths. When excitation is provided at only one wavelength, the technique is termed one-dimensional (1D) EEM fluorometry because the resulting matrix of fluorescence emission data (the EEM) contains only one row or column. When excitation is provided at multiple wavelengths, the technique is termed two-dimensional (2D) EEM fluorometry because the resulting EEM contains multiple rows and columns. EEM fluorometry - especially the 2D variety - is well established as a means of simultaneously detecting numerous dissolved and particulate compounds in water. Each compound or pool of compounds has a unique spectral fluorescence signature, and each EEM is rich in information content, in that it can contain multiple fluorescence signatures. By use of deconvolution and/or other mixture-analyses techniques, it is often possible to isolate the spectral signature of compounds of interest, even when their fluorescence spectra overlap. What distinguishes the present 2D EEMF over prior laboratory-type 2D EEMFs are several improvements in packaging (including a sealed housing) and other aspects of design that render it suitable for use in natural underwater

  7. Adaptive control of nonlinear underwater robotic systems

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1991-04-01

    Full Text Available The problem of controlling underwater mobile robots in 6 degrees of freedom (DOF is addressed. Uncertainties in the input matrix due to partly known nonlinear thruster characteristics are modeled as multiplicative input uncertainty. This paper proposes two methods to compensate for the model uncertainties: (1 an adaptive passivity-based control scheme and (2 deriving a hybrid (adaptive and sliding controller. The hybrid controller consists of a switching term which compensates for uncertainties in the input matrix and an on-line parameter estimation algorithm. Global stability is ensured by applying Barbalat's Lyapunovlike lemma. The hybrid controller is simulated for the horizontal motion of the Norwegian Experimental Remotely Operated Vehicle (NEROV.

  8. Collision Detection for Underwater ROV Manipulator Systems.

    Science.gov (United States)

    Sivčev, Satja; Rossi, Matija; Coleman, Joseph; Omerdić, Edin; Dooly, Gerard; Toal, Daniel

    2018-04-06

    Work-class ROVs equipped with robotic manipulators are extensively used for subsea intervention operations. Manipulators are teleoperated by human pilots relying on visual feedback from the worksite. Operating in a remote environment, with limited pilot perception and poor visibility, manipulator collisions which may cause significant damage are likely to happen. This paper presents a real-time collision detection algorithm for marine robotic manipulation. The proposed collision detection mechanism is developed, integrated into a commercial ROV manipulator control system, and successfully evaluated in simulations and experimental setup using a real industry standard underwater manipulator. The presented collision sensing solution has a potential to be a useful pilot assisting tool that can reduce the task load, operational time, and costs of subsea inspection, repair, and maintenance operations.

  9. The NESTOR underwater neutrino telescope project

    International Nuclear Information System (INIS)

    Rapidis, Petros A.

    2009-01-01

    The NESTOR collaboration is continuing its efforts towards deploying an underwater neutrino telescope. Further site studies (e.g. water light transmission measurements, sedimentation rates, etc.) are being carried out within the context of characterizing a site that may host the proposed KM3NeT infrastructure. In addition, following the successful deployment of a single floor of a NESTOR tower in 2003, five floors are now in the final stages of preparation. The use of these five floors in a form of a truncated tower together with four autonomous strings to be located some 300 m away from the tower is being contemplated. This arrangement, named NuBE (for Neutrino Burst Experiment), that may allow the detection neutrinos in coincidence with Gamma Ray Bursts, will be described.

  10. Self-Assessment of Hearing and Purchase of Hearing Aids by Middle-Aged and Elderly Adults

    Directory of Open Access Journals (Sweden)

    Otavio, Andressa Colares da Costa

    2015-06-01

    Full Text Available Introduction Presbycusis is a consequence of aging. Prescription of hearing aids is part of the treatment, although the prevalence of use by elderly people is still small. Objective To verify whether or not self-assessment of hearing is a predictor for purchase of hearing aids. Methods Quantitative, cross-sectional, descriptive, and observational study. Participants were subjects who sought a private hearing center for selection of hearing aids. During the diagnostic interview, subjects answered the following question: “On a scale of 1 to 10, with 1 being the worst and 10 the best, how would you rate your overall hearing ability?” After that, subjects underwent audiometry, selected a hearing aid, performed a home trial, and decided whether or not to purchase the hearing aid. The variables were associated and analyzed statistically. Results The sample was comprised of 32 subjects, both men and women, with a higher number of women. Mean age was 71.41 ± 12.14 years. Self-assessment of hearing ranged from 2 to 9 points. Overall, 71.9% of the subjects purchased hearing aids. There was no association between scores in the self-assessment and the purchase of hearing aids (p = 0.263. Among those who scored between 2 and 5 points, 64.7% purchased the device; between 6 and 7 points, 76.09% purchased the device; and between 8 and 9 points, 50% purchased the device, respectively. Conclusion There is evidence that low self-assessment scores lead to the purchase of hearing aids, although no significant association was observed in the sample.

  11. Morphing hull implementation for unmanned underwater vehicles

    International Nuclear Information System (INIS)

    Miller, Timothy F; Gandhi, Farhan; Rufino, Russell J

    2013-01-01

    There has been much interest and work in the area of morphing aircraft since the 1980s. Morphing could also potentially benefit unmanned underwater vehicles (UUVs). The current paper envisions a UUV with an interior pressure hull and a variable diameter outer flexible hull with fuel stored in the annulus between, and presents a mechanism to realize diameter change of the outer hull. The outer hull diameter of UUVs designed for very long endurance/range could be progressively reduced as fuel was consumed, thereby reducing drag and further increasing endurance and range capability. Diameter morphing could also be advantageous for compact storage of UUVs. A prototype is fabricated to represent an axial section of such a morphing diameter UUV. Diameter change is achieved using eight morphing trusses arranged equidistant around the circumference of the representative interior rigid hull. Each morphing truss has a lower rail (attached to the rigid hull) and an upper rail with V-linkages between, at either ends of the rail. Horizontal motion of the feet of the V-linkages (sliding in the lower rail) results in vertical motion of the upper rail which in turn produces diameter change of the outer hull. For the prototype built and tested, a 63% increase in outer diameter from 12.75″ to 20.75″ was achieved. The introduction of a stretched latex representative flexible skin around the outer rails increased actuation force requirement and led to a propensity for the wheel-in-track sliders in the morphing truss to bind. It is anticipated that this could be overcome with higher precision manufacturing. In addition to symmetric actuation of the morphing trusses resulting in diameter change, the paper also shows that with asymmetric actuation the hull cross-section shape can be changed (for example, from a circular section for underwater operation to a V-section for surface operations). (paper)

  12. On sampling the ocean using underwater gliders

    Science.gov (United States)

    Rudnick, Daniel L.; Cole, Sylvia T.

    2011-08-01

    The sampling characteristics of an underwater glider are addressed through comparison with contemporaneous measurements from a ship survey using a towed vehicle. The comparison uses the underwater glider Spray and the towed vehicle SeaSoar north of Hawaii along 158°W between 22.75°N and 34.5°N. A Spray dive from the surface to 1000 m and back took 5.6 h and covered 5.3 km, resulting in a horizontal speed of 0.26 m s-1. SeaSoar undulated between the surface and 400 m, completing a cycle in 11 min while covering 2.6 km, for a speed of 3.9 m s-1. Adjacent profiles of temperature and salinity are compared between the two platforms to prove that each is accurate. Spray and SeaSoar data are compared through sections, isopycnal spatial series, and wave number spectra. The relative slowness of the glider results in the projection of high-frequency oceanic variability, such as internal waves, onto spatial structure. The projection is caused by Doppler smearing because of finite speed and aliasing due to discrete sampling. The projected variability is apparent in properties measured on depth surfaces or in isopycnal depth. No projected variability is seen in observations of properties on constant density surfaces because internal waves are intrinsically filtered. Wave number spectra suggest that projected variability affects properties at constant depth at wavelengths shorter than 30 km. These results imply that isobaric quantities, like geostrophic shear, are valid at wavelengths longer than 30 km, while isopycnal quantities, like spice, may be analyzed for scales as small as a glider measures.

  13. Short Communication Evaluation of an underwater biopsy probe for ...

    African Journals Online (AJOL)

    lethal methods may become an increasingly useful tool to investigate shark populations where researchers encounter logistical or conservation-related constraints. Keywords: biopsy probe, laser photogrammetry, non-lethal sampling, underwater ...

  14. Digital sonar design in underwater acoustics principles and applications

    CERN Document Server

    Li, Qihu

    2012-01-01

    "Digital Sonar Design in Underwater Acoustics Principles and Applications" provides comprehensive and up-to-date coverage of research on sonar design, including the basic theory and techniques of digital signal processing, basic concept of information theory, ocean acoustics, underwater acoustic signal propagation theory, and underwater signal processing theory. This book discusses the general design procedure and approaches to implementation, the design method, system simulation theory and techniques, sonar tests in the laboratory, lake and sea, and practical validation criteria and methods for digital sonar design. It is intended for researchers in the fields of underwater signal processing and sonar design, and also for navy officers and ocean explorers. Qihu Li is a professor at the Institute of Acoustics, Chinese Academy of Sciences, and an academician of the Chinese Academy of Sciences.

  15. Automated Underwater Image Restoration and Retrieval of Related Optical Properties

    National Research Council Canada - National Science Library

    Hou, Weilin; Gray, Deric J; Weidemann, Alan D; Fournier, Georges R; Forand, J. L

    2007-01-01

    ...) in the spatial domain and the modulation transfer function (MTF) in the frequency domain. Due to the intensity variations involved in underwater sensing, denoising is carefully carried out by wavelet decompositions...

  16. Wireless Underwater Monitoring Systems Based on Energy Harvestings

    Directory of Open Access Journals (Sweden)

    Sea-Hee HWANGBO

    2013-01-01

    Full Text Available One of the important research fields for aquatic exploitation and conservation is underwater wireless sensor network. Since limited energy source for underwater nodes and devices is a main open problem, in this paper, we propose wireless underwater monitoring systems powered by energy harvester which resolves the energy constraint. The target system generates renewable energy from energy harvester and shares the energy with underwater sensor nodes. For the realization of the system, key components to be investigated are discriminated as follows: acoustic modem, actuator, smart battery charge controller, energy harvester and wireless power transfer module. By developing acoustic modem, actuator and smart battery charge controller and utilizing off-the-shelf energy harvester and wireless power transfer module, we design and implement a prototype of the system. Also, we verify the feasibility of concept of target system by conducting indoor and outdoor experiments.

  17. Trade-off Analysis of Underwater Acoustic Sensor Networks

    Science.gov (United States)

    Tuna, G.; Das, R.

    2017-09-01

    In the last couple of decades, Underwater Acoustic Sensor Networks (UASNs) were started to be used for various commercial and non-commercial purposes. However, in underwater environments, there are some specific inherent constraints, such as high bit error rate, variable and large propagation delay, limited bandwidth capacity, and short-range communications, which severely degrade the performance of UASNs and limit the lifetime of underwater sensor nodes as well. Therefore, proving reliability of UASN applications poses a challenge. In this study, we try to balance energy consumption of underwater acoustic sensor networks and minimize end-to-end delay using an efficient node placement strategy. Our simulation results reveal that if the number of hops is reduced, energy consumption can be reduced. However, this increases end-to-end delay. Hence, application-specific requirements must be taken into consideration when determining a strategy for node deployment.

  18. Object detection from images obtained through underwater turbulence medium

    Science.gov (United States)

    Furhad, Md. Hasan; Tahtali, Murat; Lambert, Andrew

    2017-09-01

    Imaging through underwater experiences severe distortions due to random fluctuations of temperature and salinity in water, which produces underwater turbulence through diffraction limited blur. Lights reflecting from objects perturb and attenuate contrast, making the recognition of objects of interest difficult. Thus, the information available for detecting underwater objects of interest becomes a challenging task as they have inherent confusion among the background, foreground and other image properties. In this paper, a saliency-based approach is proposed to detect the objects acquired through an underwater turbulent medium. This approach has drawn attention among a wide range of computer vision applications, such as image retrieval, artificial intelligence, neuro-imaging and object detection. The image is first processed through a deblurring filter. Next, a saliency technique is used on the image for object detection. In this step, a saliency map that highlights the target regions is generated and then a graph-based model is proposed to extract these target regions for object detection.

  19. Filming Underwater in 3d Respecting Stereographic Rules

    Science.gov (United States)

    Rinaldi, R.; Hordosch, H.

    2015-04-01

    After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie's box offices due to the overall quality of its products. Special environments such as space ("Gravity") and the underwater realm look perfect to be reproduced in 3D. "Filming in space" was possible in "Gravity" using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  20. Collision Avoidance of Moving Obstacles for Underwater Robots

    Directory of Open Access Journals (Sweden)

    KWON KYOUNG YOUB

    2006-10-01

    Full Text Available A fuzzy logic for autonomous navigation of underwater robot is proposed in this paper. The VFF(Virtual Force Field algorithm, which is widely used in the field of mobile robot, is modified for application to the autonomous navigation of underwater robot. This Modified Virtual Force Field(MVFF algorithm using the fuzzy logic can be used in either track keeping or obstacle avoidance. Fuzzy logics are devised to handle various situations which can be faced during autonomous navigation of underwater robot. A graphic simulator based on OpenGL for an autonomous navigation has been developed. The good performance of the proposed MVFF algorithm is verified through computer simulations on an underwater robot.

  1. Multi-layer protective armour for underwater shock wave mitigation

    Directory of Open Access Journals (Sweden)

    Ahmed Hawass

    2015-12-01

    The strain gauge data and displacement sensors results showed that the multi-layer plates have higher level of underwater shock wave mitigation than the triple aluminum plates with strain and deflection of nearly 50%.

  2. Underwater image enhancement through depth estimation based on random forest

    Science.gov (United States)

    Tai, Shen-Chuan; Tsai, Ting-Chou; Huang, Jyun-Han

    2017-11-01

    Light absorption and scattering in underwater environments can result in low-contrast images with a distinct color cast. This paper proposes a systematic framework for the enhancement of underwater images. Light transmission is estimated using the random forest algorithm. RGB values, luminance, color difference, blurriness, and the dark channel are treated as features in training and estimation. Transmission is calculated using an ensemble machine learning algorithm to deal with a variety of conditions encountered in underwater environments. A color compensation and contrast enhancement algorithm based on depth information was also developed with the aim of improving the visual quality of underwater images. Experimental results demonstrate that the proposed scheme outperforms existing methods with regard to subjective visual quality as well as objective measurements.

  3. Navigation of autonomous underwater vehicle using extended kalman filter

    Digital Repository Service at National Institute of Oceanography (India)

    Ranjan, T.N.; Nherakkol, A.; Navelkar, G.S.

    To navigate the Autonomous Underwater Vehicle (AUV) accurately is one of the most important aspects in its application. A truly autonomous vehicle must determine its position which requires the optimal integration of all available attitude...

  4. Euclidean reconstruction of natural underwater scenes using optic imagery sequence

    Science.gov (United States)

    Hu, Han

    The development of maritime applications require monitoring, studying and preserving of detailed and close observation on the underwater seafloor and objects. Stereo vision offers advanced technologies to build 3D models from 2D still overlapping optic images in a relatively inexpensive way. However, while image stereo matching is a necessary step in 3D reconstruction procedure, even the most robust dense matching techniques are not guaranteed to work for underwater images due to the challenging aquatic environment. In this thesis, in addition to a detailed introduction and research on the key components of building 3D models from optic images, a robust modified quasi-dense matching algorithm based on correspondence propagation and adaptive least square matching for underwater images is proposed and applied to some typical underwater image datasets. The experiments demonstrate the robustness and good performance of the proposed matching approach.

  5. Underwater acoustic communications. From point-to-point to networks

    OpenAIRE

    Jesus, S. M.

    2013-01-01

    This is a review presentation that addresses recent developments in underwater acoustic telemetry as a tool for ocean observation, monitoring and protection. Distributed sensing is a paradigm with important reflections in oceanic technology where bottom installed structures can not always be connected to a central hub through cabled networks. Moreover, recent developments in ocean robotics lead to the off-the-shelf availability of autonomous underwater vehicles that rely on wireless communica...

  6. Estimation of underwater acoustic fields at high frequencies

    OpenAIRE

    Temsamani, A.B.; Vandenplas, S.; Van Biesen, L.

    2001-01-01

    In this work a parametric modeling of the underwater acoustic field is investigated in a laboratory scale at high frequencies (150-850 kHz). The aim is to develop experimentally verifiable theoretical models to investigate the acoustic field propagation in elastic and viscoelastic or porous media. To achieve this goal, the efforts have been directed to three integral parts pertaining to the development of the methods. The first part deals with the modeling of the underwater acoustic field fol...

  7. Underwater striling engine design with modified one-dimensional model

    OpenAIRE

    Li, Daijin; Qin, Kan; Luo, Kai

    2015-01-01

    Stirling engines are regarded as an efficient and promising power system for underwater devices. Currently, many researches on one-dimensional model is used to evaluate thermodynamic performance of Stirling engine, but in which there are still some aspects which cannot be modeled with proper mathematical models such as mechanical loss or auxiliary power. In this paper, a four-cylinder double-acting Stirling engine for Unmanned Underwater Vehicles (UUVs) is discussed. And a one-dimensional mod...

  8. Characterization of ships as sources of underwater noise

    OpenAIRE

    Jong, C.A.F. de

    2009-01-01

    There is a growing interest in the possible impact of anthropogenic underwater noise on marine life [1]. One of the concerns is the increasing contribution of shipping noise, with the growing number and size of commercial ships. Traditionally, underwater radiated noise control was only of interest for naval [2,3] and fishery research vessels [4]. Due to the potential environmental impact, it becomes also relevant for commercial shipping. The challenge is to bring the expertise from the naval ...

  9. Remote Underwater Characterization System - Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    Willis, Walter David

    1999-01-01

    Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The underwater characterization equipment is often required to operate at depths exceeding 20 ft (6.1 m) and in relatively confined or congested spaces. The typical baseline approach has been the use of radiation detectors and underwater cameras mounted on long poles, or stationary cameras with pan and tilt features mounted on the sides of the underwater facility. There is a perceived need for an inexpensive, more mobile method of performing close-up inspection and radiation measurements in confined spaces underwater. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available ''Scallop'' vehicle, but has been modified by Department of Energy's Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at Idaho National Engineering and environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a ''head-to-head'' fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations

  10. Terminal homing position estimation forAutonomous underwater vehicle docking

    Science.gov (United States)

    2017-06-01

    79  ix LIST OF FIGURES Figure 1.  NPS REMUS 100 with WHOI Docking Station. Source: [1...underwater missions were short and quick . Now, with advanced technology, underwater missions can be as long as the user desires. The new AUVs have...the full information problem. In order to use the MHE approach for real-time applications, the optimization process should be quick and accurate

  11. A potential flow based flight simulator for an underwater glider

    OpenAIRE

    Phoemsapthawee, Surasak; Le Boulluec, Marc; Laurens, Jean-marc; Deniset, Francois

    2013-01-01

    Underwater gliders are recent innovative types of autonomous underwater vehicles (AUVs) used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of th...

  12. Analytical and Numerical Optimal Motion Planning for an Underwater Glider

    OpenAIRE

    Kraus, Robert J.

    2010-01-01

    The use of autonomous underwater vehicles (AUVs) for oceanic observation and research is becoming more common. Underwater gliders are a specific class of AUV that do not use conventional propulsion. Instead they change their buoyancy and center of mass location to control attitude and trajectory. The vehicles spend most of their time in long, steady glides, so even minor improvements in glide range can be magnified over multiple dives. This dissertation presents a rigid-body dynamic system...

  13. Boundary curvature effects on gas bubble oscillations in underwater explosion

    OpenAIRE

    Matsumoto, Kazuhiro

    1996-01-01

    The oscillation of a gas bubble produced as a result of underwater explosion could cause the severe whipping damage on nearby marine vehicle. The effects of rigid boundary curvatures to explosive gas bubble oscillation behavior in underwater were investigated. The analyses were conducted using a multimaterial Lagrangian-Eulerian finite element code, MSC/DYTRAN. The incident shock wave pressure, bubble pulse pressure, gas bubble radius and period were calculated for the case of detonation of a...

  14. Hearing poorly with skill

    DEFF Research Database (Denmark)

    Day, Dennis

    2012-01-01

    This paper offers an account of ongoing research into hearing. I offer a characterization of 'skil- led practitioners' from an Ethnomethodological perspective. The skilled practitioner in question is a generic 'hard of hearing' person. The ambition is that such a characterization, both in its...

  15. Hard of Hearing?

    DEFF Research Database (Denmark)

    T Christensen, Vibeke

    and social interaction in the workplace. When people develop hearing problems, the quality of their working life deteriorates in certain areas. It is the perceived deterioration of the quality of working life that causes people with impaired hearing to retire. There are clear diff erences between men...

  16. Hereditary Hearing Loss.

    Science.gov (United States)

    Tran, LenhAnh P.; Grundfast, Kenneth M.

    1997-01-01

    This article discusses inheritance patterns in hearing loss, epidemiology, clues to genetic causes, locating genes that cause hereditary disorders, genes related to hearing loss disorders in individuals with Usher syndrome, Waardenburg syndrome, Treacher-Collins syndrome, Branchio-oto-renal and Pendred syndromes, and the significance of finding…

  17. Hearing Loss and Cytomegalovirus.

    Science.gov (United States)

    Strauss, Melvin

    1997-01-01

    Cytomegalovirus is the most common cause of congenital virally induced hearing loss. Maternal infection is most often asymptomatic as is the infection in the newborn. Hearing loss occurs in both clinically apparent infection and in the asymptomatic infection. Current methods of detection, treatment, and prevention and research efforts are…

  18. Underwater and in-air sounds from a small hovercraft

    Science.gov (United States)

    Blackwell, Susanna B.; Greene, Charles R.

    2005-12-01

    Underwater and in-air recordings were made from a boat anchored near Prudhoe Bay, Alaska, while a Griffon 2000TD hovercraft drove by at or near full power on four passes. At the closest point of approach (CPA, 6.5 m), underwater broadband (10-10 000 Hz) levels reached 133 and 131 dB re: 1 μPa at depths of 1 and 7 m, respectively. In-air unweighted and A-weighted broadband (10-10 000 Hz) levels reached 104 and 97 dB re: 20 μPa, respectively. The hovercraft produced sound at a wide range of frequencies. Both underwater and in air, the largest spectral peak was near 87 Hz, which corresponded to the blade rate of the thrust propeller. In addition, the spectral composition included several harmonics of this frequency. The shaft or blade rate of the lift fan was barely detectable underwater despite its proximity to the water. The hovercraft was considerably quieter underwater than similar-sized conventional vessels and may be an attractive alternative when there is concern over underwater sounds.

  19. Optimal Node Placement in Underwater Acoustic Sensor Network

    KAUST Repository

    Felemban, Muhamad

    2011-10-01

    Almost 70% of planet Earth is covered by water. A large percentage of underwater environment is unexplored. In the past two decades, there has been an increase in the interest of exploring and monitoring underwater life among scientists and in industry. Underwater operations are extremely difficult due to the lack of cheap and efficient means. Recently, Wireless Sensor Networks have been introduced in underwater environment applications. However, underwater communication via acoustic waves is subject to several performance limitations, which makes the relevant research issues very different from those on land. In this thesis, we investigate node placement for building an initial Underwater Wireless Sensor Network infrastructure. Firstly, we formulated the problem into a nonlinear mathematic program with objectives of minimizing the total transmission loss under a given number of sensor nodes and targeted volume. We conducted experiments to verify the proposed formulation, which is solved using Matlab optimization tool. We represented each node with a truncated octahedron to fill out the 3D space. The truncated octahedrons are tiled in the 3D space with each node in the center where locations of the nodes are given using 3D coordinates. Results are supported using ns-3 simulator. Results from simulation are consistent with the obtained results from mathematical model with less than 10% error.

  20. Performance Evaluation of Hybrid Acoustic-Optical Underwater Swarm Networks

    Directory of Open Access Journals (Sweden)

    Samuela PERSIA

    2016-04-01

    Full Text Available The Underwater Swarm is a particular Underwater Network configuration characterized by nodes very close one to each other, with mobility capability. The structure of the network is that of a distributed network, in which the nodes, through the exchange of control information, will take decisions in collaborative manner. This type of network raises challenges for its effective design and development, for which the only use of acoustic communication as traditionally suggested in underwater communication could be not enough. A new emerging solution could be a hybrid solution that combines the use of acoustic and optical channel in order to overcome the acoustic channel limitations in underwater environment. In this work, we want to investigate how the acoustic and optical communications influence the Underwater Swarm performance by considering the Low Layers Protocols (Physical Layer, Data Link Layer and Network Layer effects over the two different propagation technologies. Performance simulations have been carried out to suggest how the new hybrid system could be designed. This study will permit to provide useful analysis for the real implementation of an Underwater Swarm based on hybrid communication technology.

  1. Sudden Sensorineural Hearing Loss

    Science.gov (United States)

    Kuhn, Maggie; Heman-Ackah, Selena E.; Shaikh, Jamil A.

    2011-01-01

    Sudden sensorineural hearing loss (SSNHL) is commonly encountered in audiologic and otolaryngologic practice. SSNHL is most commonly defined as sensorineural hearing loss of 30dB or greater over at least three contiguous audiometric frequencies occurring within a 72-hr period. Although the differential for SSNHL is vast, for the majority of patients an etiologic factor is not identified. Treatment for SSNHL of known etiology is directed toward that agent, with poor hearing outcomes characteristic for discoverable etiologies that cause inner ear hair cell loss. Steroid therapy is the current mainstay of treatment of idiopathic SSNHL in the United States. The prognosis for hearing recovery for idiopathic SSNHL is dependent on a number of factors including the severity of hearing loss, age, presence of vertigo, and shape of the audiogram. PMID:21606048

  2. PRECISE HEAD TRACKING IN HEARING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. M. Helle

    2015-05-01

    Full Text Available The paper gives an overview about two research projects, both dealing with optical head tracking in hearing applications. As part of the project “Development of a real-time low-cost tracking system for medical and audiological problems (ELCoT” a cost-effective single camera 3D tracking system has been developed which enables the detection of arm and head movements of human patients. Amongst others, the measuring system is designed for a new hearing test (based on the “Mainzer Kindertisch”, which analyzes the directional hearing capabilities of children in cooperation with the research project ERKI (Evaluation of acoustic sound source localization for children. As part of the research project framework “Hearing in everyday life (HALLO” a stereo tracking system is being used for analyzing the head movement of human patients during complex acoustic events. Together with the consideration of biosignals like skin conductance the speech comprehension and listening effort of persons with reduced hearing ability, especially in situations with background noise, is evaluated. For both projects the system design, accuracy aspects and results of practical tests are discussed.

  3. Hearing disorder from music; a neglected dysfunction.

    Science.gov (United States)

    Szibor, Annett; Hyvärinen, Petteri; Lehtimäki, Jarmo; Pirvola, Ulla; Ylikoski, Matti; Mäkitie, Antti; Aarnisalo, Antti; Ylikoski, Jukka

    2018-01-01

    Music-induced acute acoustic trauma is not inevitably linked to hearing dysfunction as validated by conventional pure tone audiometry. Tinnitus is often in combination with hyperacusis. Our results point at 'silent hearing loss' as the underlying pathology, having afferent nerve terminal damage rather than hair cell loss as the structural correlate. Exposure to loud music is one of the most common causes of acute acoustic trauma, which adolescents and teenagers experience by voluntary exposure to loud music of sound levels up to 110 dB(A). The clinical and psychophysical data of 104 consecutive patients with music-induced hearing disorder (MIHD) were analyzed to construct individual hearing and tinnitus profiles. In all cases, tinnitus was the presenting symptom. Hearing abilities were normal in about two-thirds of the tinnitus patients. Tinnitus was experienced most often as a high-frequency tone (83%). The Tinnitus Handicap Inventory (THI) scores ranged from 0 to 94 with an average score of 43.1. Visual analog scales (VAS) were used to assess tinnitus loudness (average 42.4) and annoyance (average 54.2), and tinnitus awareness was estimated (average 60.3). All VAS values correlated strongly with the THI. Hyperacusis was present in 65% and 71% of the patients reported sleeping disorders.

  4. Precise Head Tracking in Hearing Applications

    Science.gov (United States)

    Helle, A. M.; Pilinski, J.; Luhmann, T.

    2015-05-01

    The paper gives an overview about two research projects, both dealing with optical head tracking in hearing applications. As part of the project "Development of a real-time low-cost tracking system for medical and audiological problems (ELCoT)" a cost-effective single camera 3D tracking system has been developed which enables the detection of arm and head movements of human patients. Amongst others, the measuring system is designed for a new hearing test (based on the "Mainzer Kindertisch"), which analyzes the directional hearing capabilities of children in cooperation with the research project ERKI (Evaluation of acoustic sound source localization for children). As part of the research project framework "Hearing in everyday life (HALLO)" a stereo tracking system is being used for analyzing the head movement of human patients during complex acoustic events. Together with the consideration of biosignals like skin conductance the speech comprehension and listening effort of persons with reduced hearing ability, especially in situations with background noise, is evaluated. For both projects the system design, accuracy aspects and results of practical tests are discussed.

  5. Adjustment Problems of Hearing and Hearing-Impaired Students in ...

    African Journals Online (AJOL)

    The study examined the social and academic adjustment problems of some mainstreamed hearing and hearing-impaired students who were randomly selected from two integrated schools in Ibadan metropolis. The sample consisted of 232 junior secondary school students. 125 of them are hearing while 107 are hearing ...

  6. Hearing Aids and Hearing Impaired Students in Rural Schools.

    Science.gov (United States)

    Woodford, Charles

    This paper describes functions of the components of hearing aids and provides a detailed procedure to detect hearing aid dysfunctions. The most common type of hearing aids for school children are the behind the ear type. Various hearing aid components change sound into an electrical signal, which is amplified and adjusted by a volume control. The…

  7. Hearing Aid Acquisition in Chinese Older Adults With Hearing Loss.

    Science.gov (United States)

    He, Ping; Wen, Xu; Hu, Xiangyang; Gong, Rui; Luo, Yanan; Guo, Chao; Chen, Gong; Zheng, Xiaoying

    2018-02-01

    To investigate the prevalence and associated factors of hearing aid acquisition in Chinese older adults. We obtained data from a population-based survey on ear and hearing disorders, which was conducted in 4 provinces of China in 2014 to 2015. Trained examiners conducted pure tone audiometry and audiologists further ascertained for hearing loss. We relied on hearing conditions and audiologists' recommendations to identify 1503 participants who needed to wear hearing aids. Among those 1503 participants, the estimated prevalence of hearing aid acquisition was 6.5% (95% confidence interval = 5.3%, 7.8%). Urban residency, having severe hearing loss, understanding hearing aid function, and receiving a hearing test in the past 12 months were associated with elevated prevalence of hearing aid acquisition. The top-3 reported reasons for not acquiring a hearing aid were not understanding its function (25.4%), not needing it (22.3%), and not being able to afford it (21.3%). Hearing aid use, as a widespread rehabilitation and treatment of hearing loss, remains a big challenge in China. Apart from providing low-cost hearing aids, more efforts should focus on improving hearing knowledge and disseminating information about hearing aid function among older adults.

  8. The benefit of amplification on auditory working memory function in middle-aged and young-older hearing impaired adults

    Directory of Open Access Journals (Sweden)

    Karen A Doherty

    2015-06-01

    Full Text Available Untreated hearing loss can interfere with an individual’s cognitive abilities and intellectual function. Specifically, hearing loss has been shown to negatively impact working memory function, which is important for speech understanding, especially in difficult or noisy listening conditions. The purpose of the present study was to assess the effect of hearing aid use on auditory working memory function in middle-aged and young-older adults with mild to moderate sensorineural hearing loss. Participants completed two objective measures of auditory working memory in an aided and unaided listening condition over a six-week trial period with hearing aids. An aged matched control group followed the same experimental protocol except they were not fit with hearing aids. All participants’ aided scores on the auditory working memory tests were significantly improved after wearing hearing aids for six weeks. Thus, using hearing aids in the early stages of age-related hearing loss can improve auditory working memory performance.

  9. The hearing benefit of cochlear implantation for individuals with unilateral hearing loss, but no tinnitus.

    Science.gov (United States)

    Skarzynski, Henryk; Lorens, Artur; Kruszynska, Marika; Obrycka, Anita; Pastuszak, Dorota; Skarzynski, Piotr Henryk

    2017-07-01

    Cochlear implants improve the hearing abilities of individuals with unilateral hearing loss and no tinnitus. The benefit is no different from that seen in patients with unilateral hearing loss and incapacitating tinnitus. To evaluate hearing outcomes after cochlear implantation in individuals with unilateral hearing loss and no tinnitus and compare them to those obtained in a similar group who had incapacitating tinnitus. Six cases who did not experience tinnitus before operation and 15 subjects with pre-operative tinnitus were evaluated with a structured interview, a monosyllabic word test under difficult listening situations, a sound localization test, and an APHAB (abbreviated profile of hearing aid benefit) questionnaire. All subjects used their cochlear implant more than 8 hours a day, 7 days a week. In 'no tinnitus' patients, mean benefit of cochlear implantation was 19% for quiet speech, 15% for speech in noise (with the same signal-to-noise ratio in the implanted and non-implanted ear), and 16% for a more favourable signal-to-noise ratio at the implanted ear. Sound localization error improved by an average of 19°. The global score of APHAB improved by 16%. The benefits across all evaluations did not differ significantly between the 'no tinnitus' and 'tinnitus' groups.

  10. The effect of hearing aid noise reduction on listening effort in hearing-impaired adults.

    Science.gov (United States)

    Desjardins, Jamie L; Doherty, Karen A

    2014-01-01

    The purpose of the present study was to evaluate the effect of a noise-reduction (NR) algorithm on the listening effort hearing-impaired participants expend on a speech in noise task. Twelve hearing-impaired listeners fitted with behind-the-ear hearing aids with a fast-acting modulation-based NR algorithm participated in this study. A dual-task paradigm was used to measure listening effort with and without the NR enabled in the hearing aid. The primary task was a sentence-in-noise task presented at fixed overall speech performance levels of 76% (moderate listening condition) and 50% (difficult listening condition) correct performance, and the secondary task was a visual-tracking test. Participants also completed measures of working memory (Reading Span test), and processing speed (Digit Symbol Substitution Test) ability. Participants' speech recognition in noise scores did not significantly change with the NR algorithm activated in the hearing aid in either listening condition. The NR algorithm significantly decreased listening effort, but only in the more difficult listening condition. Last, there was a tendency for participants with faster processing speeds to expend less listening effort with the NR algorithm when listening to speech in background noise in the difficult listening condition. The NR algorithm reduced the listening effort adults with hearing loss must expend to understand speech in noise.

  11. The benefit of amplification on auditory working memory function in middle-aged and young-older hearing impaired adults

    OpenAIRE

    Doherty, Karen A.; Desjardins, Jamie L.

    2015-01-01

    Untreated hearing loss can interfere with an individual’s cognitive abilities and intellectual function. Specifically, hearing loss has been shown to negatively impact working memory function, which is important for speech understanding, especially in difficult or noisy listening conditions. The purpose of the present study was to assess the effect of hearing aid use on auditory working memory function in middle-aged and young-older adults with mild to moderate sensorineural hearing loss. P...

  12. Introduction to audiology: Some basics about hearing loss, hearing technologies and barriers to hearing aid use

    DEFF Research Database (Denmark)

    Mourtou, Eleni; Meis, Markus

    2012-01-01

    This chapter provides background information for researchers who wish to become familiar with some basic medical and audiological aspects of hearing loss and the technology of hearing aids. It introduces (1) the disciplines involved in research on hearing loss, (2) the medical categories of hearing...... loss and their various effects on communication, (3) the different degrees of hearing loss as defined by different national and international organizations, (4) statistics on the preva- lence of hearing loss worldwide, (5) some technological aspects of hearing instruments, (6) sta- tistics on non......-usage of hearing instruments worldwide, and (7) barriers to using hearing aids. Since hearing loss is a worldwide pervasive phenomenon which is likely to increase even further in the future, the authors point out that an understanding of the non-use of hearing aids is crucial....

  13. Impact of Aging and Cognition on Hearing Assistive Technology Use.

    Science.gov (United States)

    Jorgensen, Lindsey E; Messersmith, Jessica J

    2015-08-01

    Many factors go into appropriate recommendation and use of hearing assistive technology (HAT). The aging auditory system presents with its own complications and intricacies; there are many types of age-related hearing loss, and it is possible that the underlying cause of hearing loss can significantly impact the recommendations and performance with HATs. The audiologist should take into consideration peripheral and central auditory function when selecting HATs for the aging adult population as well as when selecting appropriate types of technology including personal sound amplification products, hearing aids, cochlear implants, and other assistive technology. The cognitive ability of the patient plays a central role in the recommendations of HAT. It is possible that the use of HATs could mitigate some of the effects of cognitive decline and thus should be considered as early as possible. Assessment of ability and appropriate recommendations are crucial to consistent use of HAT devices.

  14. 77 FR 44703 - Public Hearing

    Science.gov (United States)

    2012-07-30

    ... COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on August 23, 2012, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the projects listed in the...

  15. 78 FR 64260 - Public Hearing

    Science.gov (United States)

    2013-10-28

    ... COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on November 13, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the projects listed in the...

  16. 78 FR 24785 - Public Hearing

    Science.gov (United States)

    2013-04-26

    ... COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on May 23, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the projects listed in the Supplementary...

  17. 78 FR 43961 - Public Hearing

    Science.gov (United States)

    2013-07-22

    ... COMMISSION Public Hearing AGENCY: Susquehanna River Basin Commission. ACTION: Notice. SUMMARY: The Susquehanna River Basin Commission will hold a public hearing on August 15, 2013, in Harrisburg, Pennsylvania. At this public hearing, the Commission will hear testimony on the projects listed in the...

  18. Round window stimulation for conductive and mixed hearing loss.

    Science.gov (United States)

    Dillon, Margaret T; Tubbs, Rhonda S; Adunka, Marcia C; King, English R; Hillman, Todd A; Adunka, Oliver F; Chen, Douglas A; Buchman, Craig A

    2014-10-01

    Assess surgical complications, postoperative residual hearing, and speech perception outcomes of placement of a middle ear implant on the round window in conductive and mixed hearing loss cases. Single-subject, repeated-measures design where each subject served as his or her own control. Tertiary referral medical systems. Eighteen subjects with either conductive or mixed hearing loss who could not benefit from conventional amplification were enrolled in a clinical trial investigating vibratory stimulation of the round window. The floating mass transducer (FMT) was positioned in the round window niche. Unaided residual hearing, and aided sound field thresholds and speech perception abilities were evaluated preoperatively, and at 1, 3, 6, and 10 months post-activation of the external speech processor. Six subjects experienced complications that either required further medical management or resolved on their own. There was no difference in residual bone conduction thresholds or unaided word discrimination over time. All subjects experienced a significant improvement in aided speech perception abilities as compared to preoperative performance. Subjects with conductive and mixed hearing loss with placement of the FMT in the round window niche experienced improved sound field thresholds and speech perception, without compromising residual hearing thresholds. Vibratory stimulation of the round window via a middle ear implant may be an appropriate treatment option for patients with conductive and mixed hearing loss. Additional research is needed on the preferred placement of the FMT, improvement of functional gain, and methods to limit postoperative complications and need for revision surgery.

  19. The benefits of using bluetooth accessories with hearing aids.

    Science.gov (United States)

    Smith, Pauline; Davis, Adrian

    2014-10-01

    To investigate the benefits in reported outcomes after providing bluetooth accessories for established hearing aid users. Prospective observational study using validated quantitative outcome measures and detailed patient narrative before and two months after patients were provided with bluetooth accessories. Twelve patients with bilateral NHS hearing aids participated. They had a wide range of ages and hearing loss. After two months, 10 patients reported substantial additional benefit and kept the accessories; two returned them for various reasons. Statistically significant changes were seen in two validated outcome measures: the Glasgow Hearing Aid Benefit Profile and the International Outcome Inventory - Hearing Aids, but not in the Speech, Spatial and Qualities of Hearing Scale. Two notable benefits were reported: some described hearing the emotion and mood in a voice for the first time; others were amazed to report an improved ability to hear film or to hold conversations over the telephone. The provision of bluetooth accessories can give additional reported benefit for some patients - we need better knowledge about who benefits, and whether further support/training to individuals would make a difference.

  20. The comparative study of reading comprehension in normal-hearing and hearing-loss student

    Directory of Open Access Journals (Sweden)

    Gholamali Afrooz

    2012-06-01

    Full Text Available Background and Aim: In different language approaches, reading is considered as a major skill. Language skills comprising listening, speaking, reading and writing are completely interlinked with each other. Thus, providing active application of listening and speaking skills, children will learn reading and writing skills easily. The aim of this research was to compare reading skills of hearing-loss students studying at exceptional schools with normal students of different degrees.Methods: The research was conducted post-traumatically using standardized 2006 PIRLS test. 80 students in fifth grade of exceptional primary schools, and first and fourth grade of exceptional high schools in Tehran City who had severe and or profound hearing loss were randomly selected along with 80 normal students in ordinary schools who were selected using available sampling method.Results: There were significant differences between reading comprehension of hearing-loss and normal students of all three grades (p<0.001. Reading comprehension in female students was significantly higher than the male ones (p<0.001. There were not any significant differences in mean reading comprehension scores of hearing-loss students in different grades which demonstrate that their reading skills had not developed in tandem with their age and school educations.Conclusion: This study shows that one of the significant concerns regarding hearing-loss students is their reading comprehension ability. Considering reading ability as one of the most important acquisitive abilities which students learn at school, evaluation of reading skills of hearing loss students as well as recognition of their strengths and weaknesses in this field is indispensable.

  1. Interaction of tinnitus suppression and hearing ability after cochlear implantation.

    Science.gov (United States)

    Wang, Qian; Li, Jia-Nan; Lei, Guan-Xiong; Chen, Dai-Shi; Wang, Wei-Ze; Chen, Ai-Ting; Mong, Meng-Di; Li, Sun; Jiao, Qing-Shan; Yang, Shi-Ming

    2017-10-01

    To study the postoperative impact of cochlear implants (CIs) on tinnitus, as well as the impact of tinnitus on speech recognition with CI switched on. Fifty-two postlingual deafened CI recipients (21 males and 31 females) were assessed using an established Tinnitus Characteristics Questionnaire and Tinnitus Handicap Inventory (THI) before and after cochlear implantation. The tinnitus loudness was investigated when CI was switched on and off in CI recipients with persistent tinnitus. The relation between tinnitus loudness and recipients' satisfaction of cochlear implantation was analyzed by the visual analogue scale (VAS) score. With CI 'OFF', 42 CI recipients experienced tinnitus postimplant ipsilaterally and 44 contralaterally. Tinnitus was totally suppressed ipsilateral to the CI with CI 'ON' in 42.9%, partially suppressed in 42.9%, unchanged in 11.9% and aggravated in 2.4%. Tinnitus was totally suppressed contralaterally with CI 'ON' in 31.8% of CI recipients, partially suppressed in 47.7%, unchanged in 20.5%. Pearson correlation analysis showed that tinnitus loudness and the results of cochlear implant patients satisfaction was negatively correlated (r = .674, p tinnitus. The tinnitus loudness may affect patients' satisfaction with the use of CI.

  2. Autonomous Underwater Vehicle Magnetic Mapping System

    Science.gov (United States)

    Steigerwalt, R.; Johnson, R. M.; Trembanis, A. C.; Schmidt, V. E.; Tait, G.

    2012-12-01

    An Autonomous Underwater Vehicle (AUV) Magnetic Mapping (MM) System has been developed and tested for military munitions detection as well as pipeline locating, wreck searches, and geologic surveys in underwater environments. The system is comprised of a high sensitivity Geometrics G-880AUV cesium vapor magnetometer integrated with a Teledyne-Gavia AUV and associated Doppler enabled inertial navigation further utilizing traditional acoustic bathymetric and side scan imaging. All onboard sensors and associated electronics are managed through customized crew members to autonomously operate through the vehicles primary control module. Total field magnetic measurements are recorded with asynchronous time-stamped data logs which include position, altitude, heading, pitch, roll, and electrical current usage. Pre-planned mission information can be uploaded to the system operators to define data collection metrics including speed, height above seafloor, and lane or transect spacing specifically designed to meet data quality objectives for the survey. As a result of the AUVs modular design, autonomous navigation and rapid deployment capabilities, the AUV MM System provides cost savings over current surface vessel surveys by reducing the mobilization/demobilization effort, thus requiring less manpower for operation and reducing or eliminating the need for a surface support vessel altogether. When the system completes its mission, data can be remotely downloaded via W-LAN and exported for use in advanced signal processing platforms. Magnetic compensation software has been concurrently developed to accept electrical current measurements directly from the AUV to address distortions from permanent and induced magnetization effects on the magnetometer. Maneuver and electrical current compensation terms can be extracted from the magnetic survey missions to perform automated post-process corrections. Considerable suppression of system noise has been observed over traditional

  3. Underwater Animal Monitoring Magnetic Sensor System

    KAUST Repository

    Kaidarova, Altynay

    2017-10-01

    Obtaining new insights into the behavior of free-living marine organisms is fundamental for conservation efforts and anticipating the impact of climate change on marine ecosystems. Despite the recent advances in biotelemetry, collecting physiological and behavioral parameters of underwater free-living animals remains technically challenging. In this thesis, we develop the first magnetic underwater animal monitoring system that utilizes Tunnel magnetoresistance (TMR) sensors, the most sensitive solid-state sensors today, coupled with flexible magnetic composites. The TMR sensors are composed of CoFeB free layers and MgO tunnel barriers, patterned using standard optical lithography and ion milling procedures. The short and long-term stability of the TMR sensors has been studied using statistical and Allan deviation analysis. Instrumentation noise has been reduced using optimized electrical interconnection schemes. We also develop flexible NdFeB-PDMS composite magnets optimized for applications in corrosive marine environments, and which can be attached to marine animals. The magnetic and mechanical properties are studied for different NdFeB powder concentrations and the performance of the magnetic composites for different exposure times to sea water is systematically investigated. Without protective layer, the composite magnets loose more than 50% of their magnetization after 51 days in seawater. The durability of the composite magnets can be considerably improved by using polymer coatings which are protecting the composite magnet, whereby Parylene C is found to be the most effective solution, providing simultaneously corrosion resistance, flexibility, and enhanced biocompatibility. A Parylene C film of 2μm thickness provides the sufficient protection of the magnetic composite in corrosive aqueous environments for more than 70 days. For the high level performance of the system, the theoretically optimal position of the composite magnets with respect to the sensing

  4. The influence of hearing-aid compression on forward-masked thresholds for adults with hearing loss

    Science.gov (United States)

    Brennan, Marc A.; McCreery, Ryan W.; Jesteadt, Walt

    2015-01-01

    This paper describes forward-masked thresholds for adults with hearing loss. Previous research has demonstrated that the loss of cochlear compression contributes to deficits in this measure of temporal resolution. Cochlear compression can be mimicked with fast-acting compression where the normal dynamic range is mapped to the impaired dynamic range. To test the hypothesis that fast-acting compression will most-closely approximate the normal ability to perceive forward-masked pure-tones, forward-masked thresholds were measured for two groups of adults (normal hearing, hearing loss). Adults with normal hearing were tested without amplification. Adults with hearing loss were tested with three different compression speeds and two different prescriptive procedures using a hearing-aid simulator. The two prescriptive procedures differed in the extent to which the normal dynamic range was mapped onto the impaired dynamic range. When using a faster compression speed with the prescriptive procedure that best restored the lost dynamic range, forward-masked thresholds for the listeners with hearing loss approximated those observed for the listeners with normal hearing. PMID:26520341

  5. Underwater Optical Wireless Channel Modeling Using Monte-Carlo Method

    Science.gov (United States)

    Saini, P. Sri; Prince, Shanthi

    2011-10-01

    At present, there is a lot of interest in the functioning of the marine environment. Unmanned or Autonomous Underwater Vehicles (UUVs or AUVs) are used in the exploration of the underwater resources, pollution monitoring, disaster prevention etc. Underwater, where radio waves do not propagate, acoustic communication is being used. But, underwater communication is moving towards Optical Communication which has higher bandwidth when compared to Acoustic Communication but has shorter range comparatively. Underwater Optical Wireless Communication (OWC) is mainly affected by the absorption and scattering of the optical signal. In coastal waters, both inherent and apparent optical properties (IOPs and AOPs) are influenced by a wide array of physical, biological and chemical processes leading to optical variability. The scattering effect has two effects: the attenuation of the signal and the Inter-Symbol Interference (ISI) of the signal. However, the Inter-Symbol Interference is ignored in the present paper. Therefore, in order to have an efficient underwater OWC link it is necessary to model the channel efficiently. In this paper, the underwater optical channel is modeled using Monte-Carlo method. The Monte Carlo approach provides the most general and most flexible technique for numerically solving the equations of Radiative transfer. The attenuation co-efficient of the light signal is studied as a function of the absorption (a) and scattering (b) coefficients. It has been observed that for pure sea water and for less chlorophyll conditions blue wavelength is less absorbed whereas for chlorophyll rich environment red wavelength signal is absorbed less comparative to blue and green wavelength.

  6. Apps for hearing healthcare.

    Science.gov (United States)

    Paglialonga, Alessia; Tognola, Gabriella; Pinciroli, Francesco

    2015-01-01

    The hearing healthcare scenario is rapidly evolving due to the pervasive use of m-Health solutions, in particular mobile apps. This brings along significant advantages and opportunities (e.g., accessibility, affordability, personalized healthcare, patient empowerment) as well as significant potential risks and threats (e.g., safety, misuse, quality issues, privacy). Our research aims at the identification and assessment of apps in the hearing healthcare domain. In this article we present an overview of the current availability, variety, and penetration of hearing-related apps.

  7. Hearing Aid Personalization

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Nielsen, Jakob; Jensen, Bjørn Sand

    2013-01-01

    Modern digital hearing aids require and offer a great level of personalization. Today, this personalization is not performed based directly on what the user actually perceives, but on a hearing-care professional’s interpretation of what the user explains about what is perceived. In this paper......, an interactive personalization system based on Gaussian process regression and active learning is proposed, which personalize the hearing aids based directly on what the user perceives. Preliminary results demonstrate a significant difference between a truly personalized setting obtained with the proposed system...

  8. A Framework for Evaluating Advanced Search Concepts for Multiple Autonomous Underwater Vehicle (AUV) Mine Countermeasures (MCM)

    National Research Council Canada - National Science Library

    Gooding, Trent

    2001-01-01

    .... In recent years, autonomous underwater vehicles (AUV) have emerged as a viable technology for conducting underwater search, survey, and clearance operations in support of the mine countermeasures (MCM) mission...

  9. A comparative view of routing protocols for underwater wireless sensor networks

    NARCIS (Netherlands)

    Bayrakdar, Y.; Meratnia, Nirvana; Kantarci, Aylin

    2011-01-01

    Design of efficient routing protocols for underwater sensor networks is challenging because of the distinctive characteristics of the water medium. Currently, many routing protocols are available for terrestrial wireless sensor networks. However, specific properties of underwater medium such as

  10. US-Japan Cooperative Research on Biology-Inspired Precision Maneuvering of Underwater Vehicles

    National Research Council Canada - National Science Library

    Kato, Naomi

    2004-01-01

    .... We constructed an underwater vehicle equipped with two pairs of mechanical pectoral fins and pectoral fin controllers to examine the swimming performance of the underwater vehicle in still water...

  11. Predictive Model for the Analysis of the Effects of Underwater Impulsive Sources on Marine Life

    National Research Council Canada - National Science Library

    Lazauski, Colin J

    2007-01-01

    A method is provided to predict the biological consequences to marine animals from exposure to multiple underwater impulsive sources by simulating underwater explosions over a defined period of time...

  12. Shape optimisation of an underwater Bernoulli gripper

    Science.gov (United States)

    Flint, Tim; Sellier, Mathieu

    2015-11-01

    In this work, we are interested in maximising the suction produced by an underwater Bernoulli gripper. Bernoulli grippers work by exploiting low pressure regions caused by the acceleration of a working fluid through a narrow channel, between the gripper and a surface, to provide a suction force. This mechanism allows for non-contact adhesion to various surfaces and may be used to hold a robot to the hull of a ship while it inspects welds for example. A Bernoulli type pressure analysis was used to model the system with a Darcy friction factor approximation to include the effects of frictional losses. The analysis involved a constrained optimisation in order to avoid cavitation within the mechanism which would result in decreased performance and damage to surfaces. A sensitivity based method and gradient descent approach was used to find the optimum shape of a discretised surface. The model's accuracy has been quantified against finite volume computational fluid dynamics simulation (ANSYS CFX) using the k- ω SST turbulence model. Preliminary results indicate significant improvement in suction force when compared to a simple geometry by retaining a pressure just above that at which cavitation would occur over as much surface area as possible. Doctoral candidate in the Mechanical Engineering Department of the University of Canterbury, New Zealand.

  13. Underwater radiated noise from modern commercial ships.

    Science.gov (United States)

    McKenna, Megan F; Ross, Donald; Wiggins, Sean M; Hildebrand, John A

    2012-01-01

    Underwater radiated noise measurements for seven types of modern commercial ships during normal operating conditions are presented. Calibrated acoustic data (autonomous seafloor-mounted acoustic recorder were combined with ship passage information from the Automatic Identification System. This approach allowed for detailed measurements (i.e., source level, sound exposure level, and transmission range) on ships of opportunity. A key result was different acoustic levels and spectral shapes observed from different ship-types. A 54 kGT container ship had the highest broadband source level at 188 dB re 1 μPa@1m; a 26 kGT chemical tanker had the lowest at 177 dB re 1 μPa@1m. Bulk carriers had higher source levels near 100 Hz, while container ship and tanker noise was predominantly below 40 Hz. Simple models to predict source levels of modern merchant ships as a group from particular ship characteristics (e.g., length, gross tonnage, and speed) were not possible given individual ship-type differences. Furthermore, ship noise was observed to radiate asymmetrically. Stern aspect noise levels are 5 to 10 dB higher than bow aspect noise levels. Collectively, these results emphasize the importance of including modern ship-types in quantifying shipping noise for predictive models of global, regional, and local marine environments. © 2012 Acoustical Society of America.

  14. The Modular Optical Underwater Survey System

    Directory of Open Access Journals (Sweden)

    Ruhul Amin

    2017-10-01

    Full Text Available The Pacific Islands Fisheries Science Center deploys the Modular Optical Underwater Survey System (MOUSS to estimate the species-specific, size-structured abundance of commercially-important fish species in Hawaii and the Pacific Islands. The MOUSS is an autonomous stereo-video camera system designed for the in situ visual sampling of fish assemblages. This system is rated to 500 m and its low-light, stereo-video cameras enable identification, counting, and sizing of individuals at a range of 0.5–10 m. The modular nature of MOUSS allows for the efficient and cost-effective use of various imaging sensors, power systems, and deployment platforms. The MOUSS is in use for surveys in Hawaii, the Gulf of Mexico, and Southern California. In Hawaiian waters, the system can effectively identify individuals to a depth of 250 m using only ambient light. In this paper, we describe the MOUSS’s application in fisheries research, including the design, calibration, analysis techniques, and deployment mechanism.

  15. Autonomous Underwater Vehicle Thermoelectric Power Generation

    Science.gov (United States)

    Buckle, J. R.; Knox, A.; Siviter, J.; Montecucco, A.

    2013-07-01

    Autonomous underwater vehicles (AUVs) are a vital part of the oceanographer's toolbox, allowing long-term measurements across a range of ocean depths of a number of ocean properties such as salinity, fluorescence, and temperature profile. Buoyancy-based gliding, rather than direct propulsion, dramatically reduces AUV power consumption and allows long-duration missions on the order of months rather than hours or days, allowing large distances to be analyzed or many successive analyses of a certain area without the need for retrieval. Recent versions of these gliders have seen the buoyancy variation system change from electrically powered to thermally powered using phase-change materials, however a significant battery pack is still required to power communications and sensors, with power consumption in the region of 250 mW. The authors propose a novel application of a thermoelectric generation system, utilizing the depth-related variation in oceanic temperature. A thermal energy store provides a temperature differential across which a thermoelectric device can generate from repeated dives, with the primary purpose of extending mission range. The system is modeled in Simulink to analyze the effect of variation in design parameters. The system proves capable of generating all required power for a modern AUV.

  16. Data extraction system for underwater particle holography

    Science.gov (United States)

    Nebrensky, J. J.; Craig, Gary; Hobson, Peter R.; Lampitt, R. S.; Nareid, Helge; Pescetto, A.; Trucco, Andrea; Watson, John

    2000-08-01

    Pulsed laser holography in an extremely powerful technique for the study of particle fields as it allows instantaneous, non-invasive high- resolution recording of substantial volumes. By relaying the real image one can obtain the size, shape, position and - if multiple exposures are made - velocity of every object in the recorded field. Manual analysis of large volumes containing thousands of particles is, however, an enormous and time-consuming task, with operator fatigue an unpredictable source of errors. Clearly the value of holographic measurements also depends crucially on the quality of the reconstructed image: not only will poor resolution degrade the size and shape measurements, but aberrations such as coma and astigmatism can change the perceived centroid of a particle, affecting position and velocity measurements. For large-scale applications of particle field holography, specifically the in situ recording of marine plankton with Holocam, we have developed an automated data extraction system that can be readily switched between the in-line and off-axis geometries and provides optimised reconstruction from holograms recorded underwater. As a videocamera is automatically stepped through the 200 by 200 by 1000mm sample volume, image processing and object tracking routines locate and extract particle images for further classification by a separate software module.

  17. Devices for hearing loss

    Science.gov (United States)

    ... the sounds you want to hear. Assistive listening devices bring certain sounds directly to your ears. This can ... a small room or on a stage. Other devices can bring the sound from your TV, radio, or music ...

  18. Hearing Conservation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Hearing Conservation Team focuses on ways to identify the early stages of noise-induced damage to the human ear.Our current research involves the evaluation of...

  19. Types of Hearing Aids

    Science.gov (United States)

    ... certain situations (for example, background noise and whistle reduction). They also have greater flexibility in hearing aid programming so that the sound they transmit can be matched to the needs ...

  20. Hearing regulates Drosophila aggression.

    Science.gov (United States)

    Versteven, Marijke; Vanden Broeck, Lies; Geurten, Bart; Zwarts, Liesbeth; Decraecker, Lisse; Beelen, Melissa; Göpfert, Martin C; Heinrich, Ralf; Callaerts, Patrick

    2017-02-21

    Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

  1. Hearing loss and music

    Science.gov (United States)

    ... iPod or MP3 Player The small ear bud style headphones (inserted into the ears) DO NOT block ... chap 152. National Institute on Deafness and Other Communication Disorders. Noise-induced hearing loss. NIH Pub. No. ...

  2. Regional Hearing Clerk

    Science.gov (United States)

    The Regional Hearing Clerk receives filings for proceedings under the Consolidated Rules of Practice Governing the Administrative Assessment of Civil Penalties and the Revocation/Termination or Suspension of Permits, 40 Code of Federal Regulations Part 22

  3. Research of Algorithms for Approaching and Docking Underwater Vehicle with Underwater Station

    Directory of Open Access Journals (Sweden)

    Pshikhopov Vyacheslav

    2015-01-01

    Full Text Available Authors consider problem of maintenance and service of underwater vehicles. Usually, underwater station or accompanying ship is required for such operations. Docking is one of the most difficult tasks on the vehicle path from the outer space to the servicing bay. Algorithms allowing docking were presented in the earlier paper, and in this paper authors prove their stability. Movement control is based upon the path regulator. The stability of the closed-loop system according to Liapunov with the given control and limitations is proven. Equations, showing that vehicle will complete the positioning task with account to given limitations and staying stable are given. The criterion for switching movement and “positioning to point” algorithms is proposed. Achievement of the developed criterion was researched theoretically and in computer simulation. Experiments provide deviation of actual coordinates and velocity from the required ones and proved that achieving of criterion is enough to claim that system will be stable while performing algorithms with limitations for controls.

  4. Autonomous docking control of visual-servo type underwater vehicle system aiming at underwater automatic charging

    International Nuclear Information System (INIS)

    Yanou, Akira; Ohnishi, Shota; Ishiyama, Shintaro; Minami, Mamoru

    2015-01-01

    A visual-servo type remotely operated vehicle (ROV) system with binocular wide-angle lens was developed to survey submarine resources, decontaminate radiation from mud in dam lake and so on. This paper explores the experiments on regulator performance and underwater docking of the robot system utilizing Genetic Algorithm (GA) for real-time recognition of the robot's relative position and posture through 3D marker. The visual servoing performances have been verified as follows; (1) The stability performances of the proposed regulator system have been evaluated by exerting abrupt distrubane force while the ROV is controlled by visual servoing. (2) The proposed system can track time-variant desired target position in x-axis (front-back direction of the robot). (3) The underwater docking can be completed by switching visual servoing and docking modes based on the error threshold, and by giving time-varying desired target position and orientation to the controller as a desired pose. (author)

  5. Does Acquired Hypothyroidism Affect the Hearing Functions?

    Directory of Open Access Journals (Sweden)

    Ayşe Arduç

    2015-12-01

    Full Text Available Purpose: It is well known that congenital hypothyroidism can cause hearing loss. However, conflicting results were found in studies investigating hearing functions in acquired hypothyroidism. Therefore, we evaluated the audiometric findings in patients with acquired hypothyroidism. Material and Method: The study included 58 patients with hypothyroidism and age- and gender-matched 34 healthy controls. Twenty eight (48.27% patients had subclinical hypothyroidism, and 30 (51.73% had obvious hypothyroidism. All subjects had a normal otoscopic examination and tympanometry. Pure tone audiometry at 250, 500, 1000, 2000, 4000, 6000, and 8000 Hertz (Hz was performed in both groups. Blood pressure measurements and the levels of plasma electrolytes, lipids and vitamin B12 were available in all subjects. Results: Hypothyroidism group and control group were similar with respect to systolic and diastolic blood pressures and plasma glucose, lipid, vitamin B12, calcium, sodium, potassium, and chloride levels. Significantly higher audiometric thresholds (dB at 250 (10 (0-45 vs. 5 (0-15, p<0.001 and 500 Hz (10 (0-40 vs. 10 (-5-15, p=0.003 were recorded in hypothyroid patients compared to that in healthy controls. Hearing thresholds at 250 and 500 Hz correlated positively with thyroid-stimulating hormone (TSH, and negatively with free triiodothyronine and free thyroxine. Subclinical hypothyroid patients had a higher hearing threshold at 250 Hz than healthy controls (p=0.001. Discussion: Our study demonstrated that hearing ability decreases in hypothyroidism, even in subclinical hypothyroidism. The changes in TSH and thyroid hormone levels seem to be directly related to the hearing loss in this population of patients.

  6. Differences in speech processing among elderly hearing-impaired listeners with or without hearing aid experience: Eye-tracking and fMRI measurements

    DEFF Research Database (Denmark)

    Habicht, Julia; Behler, Oliver; Kollmeier, Birger

    2018-01-01

    -only condition was also included. Groups of elderly hearing-impaired individuals matched in terms of age, hearing loss and working memory capacity with (eHA; N = 13) or without (iHA; N = 14) HA experience participated. All acoustic stimuli were presented via earphones with individual linear amplification......Recently, evidence has been accumulating that untreated hearing loss can lead to neurophysiological changes that affect speech-in-noise processing abilities. In order to explore how aiding impacts these effects, this study examined the influence of hearing aid (HA) experience on the cognitive...

  7. Modeling and Simulation of Underwater Flexible Manipulator as Raleigh Beam Using Bond Graph

    OpenAIRE

    Sumit Kumar; Sunil Kumar; Chandan Deep Singh

    2015-01-01

    This paper presents modeling and simulation of flexible robot in an underwater environment. The underwater environment completely contrasts with ground or space environment. The robot in an underwater situation is subjected to various dynamic forces like buoyancy forces, hydrostatic and hydrodynamic forces. The underwater robot is modeled as Rayleigh beam. The developed model further allows estimating the deflection of tip in two directions. The complete dynamics of the u...

  8. Evaluation of a Modified User Guide for Hearing Aid Management.

    Science.gov (United States)

    Caposecco, Andrea; Hickson, Louise; Meyer, Carly; Khan, Asaduzzaman

    2016-01-01

    This study investigated if a hearing aid user guide modified using best practice principles for health literacy resulted in superior ability to perform hearing aid management tasks, compared with the user guide in the original form. This research utilized a two-arm study design to compare the original manufacturer's user guide with a modified user guide for the same hearing aid--an Oticon Acto behind-the-ear aid with an open dome. The modified user guide had a lower reading grade level (4.2 versus 10.5), used a larger font size, included more graphics, and had less technical information. Eighty-nine adults ages 55 years and over were included in the study; none had experience with hearing aid use or management. Participants were randomly assigned either the modified guide (n = 47) or the original guide (n = 42). All participants were administered the Hearing Aid Management test, designed for this study, which assessed their ability to perform seven management tasks (e.g., change battery) with their assigned user guide. The regression analysis indicated that the type of user guide was significantly associated with performance on the Hearing Aid Management test, adjusting for 11 potential covariates. In addition, participants assigned the modified guide required significantly fewer prompts to perform tasks and were significantly more likely to perform four of the seven tasks without the need for prompts. The median time taken by those assigned the modified guide was also significantly shorter for three of the tasks. Other variables associated with performance on the Hearing Aid Management test were health literacy level, finger dexterity, and age. Findings indicate that the need to design hearing aid user guides in line with best practice principles of health literacy as a means of facilitating improved hearing aid management in older adults.

  9. Design and implementation of an underwater sound recording device.

    Science.gov (United States)

    Martinez, Jayson J; Myers, Josh R; Carlson, Thomas J; Deng, Z Daniel; Rohrer, John S; Caviggia, Kurt A; Woodley, Christa M; Weiland, Mark A

    2011-01-01

    To monitor the underwater sound and pressure waves generated by anthropogenic activities such as underwater blasting and pile driving, an autonomous system was designed to record underwater acoustic signals. The underwater sound recording device (USR) allows for connections of two hydrophones or other dynamic pressure sensors, filters high frequency noise out of the collected signals, has a gain that can be independently set for each sensor, and allows for 2 h of data collection. Two versions of the USR were created: a submersible model deployable to a maximum depth of 300 m, and a watertight but not fully submersible model. Tests were performed on the USR in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to each component. These tests verified that the device operates as designed and performs as well as larger commercially available data acquisition systems, which are not suited for field use. On average, the designed gain values differed from the actual measured gain values by about 0.35 dB. A prototype of the device was used in a case study to measure blast pressures while investigating the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. In the case study, maximum positive pressure from the blast was found to be significantly correlated with frequency of injury for individual fish. The case study also demonstrated that the device withstood operation in harsh environments, making it a valuable tool for collecting field measurements.

  10. Design and Implementation of an Underwater Sound Recording Device

    Directory of Open Access Journals (Sweden)

    Christa M. Woodley

    2011-09-01

    Full Text Available To monitor the underwater sound and pressure waves generated by anthropogenic activities such as underwater blasting and pile driving, an autonomous system was designed to record underwater acoustic signals. The underwater sound recording device (USR allows for connections of two hydrophones or other dynamic pressure sensors, filters high frequency noise out of the collected signals, has a gain that can be independently set for each sensor, and allows for 2 h of data collection. Two versions of the USR were created: a submersible model deployable to a maximum depth of 300 m, and a watertight but not fully submersible model. Tests were performed on the USR in the laboratory using a data acquisition system to send single-frequency sinusoidal voltages directly to each component. These tests verified that the device operates as designed and performs as well as larger commercially available data acquisition systems, which are not suited for field use. On average, the designed gain values differed from the actual measured gain values by about 0.35 dB. A prototype of the device was used in a case study to measure blast pressures while investigating the effect of underwater rock blasting on juvenile Chinook salmon and rainbow trout. In the case study, maximum positive pressure from the blast was found to be significantly correlated with frequency of injury for individual fish. The case study also demonstrated that the device withstood operation in harsh environments, making it a valuable tool for collecting field measurements.

  11. Underwater topography acquired by remote sensing based on SOFM

    Science.gov (United States)

    Zhao, Jianhu; Zhou, Fengnian; Zhang, Hongmei; Li, Juanjuan

    2008-12-01

    In large-scope marine investigation, the traditional bathymetric measurement can not meet the requirement of rapid data acquisition with lower cost of financial and material resources, while remote sensing (RS) technology provides a perfect way in the work. RS can not only provide quickly and efficiently the information of underwater topography with respect to the traditional method, but also present corresponding underwater topography with different-period RS images. In this paper, we depict in detail the procedures and some key techniques in acquiring underwater topography by remote sensing inversion technology based on self-organization feature mapping (SOFM). Firstly, we introduce some basic theories about the acquisition of underwater topography by the RS inversion technology. Besides, we discuss the data acquisition and preparation in the work. Moreover, we implement correlation analysis and find out the sensitive bands used for building RS inversion model. In virtue of SOFM, we construct the mapping relation between water depth and the reflectivity of sensitive band in the studied area, and test the it in two experimental water areas. The model achieves satisfying accuracy and can meet the requirement of given bathymetric scale. Finally the mapping relation is used for the water depth inversion in the studied water area. We also use the water depth from the model to draw the underwater topographic map in the water area.

  12. A bio-inspired electrocommunication system for small underwater robots.

    Science.gov (United States)

    Wang, Wei; Liu, Jindong; Xie, Guangming; Wen, Li; Zhang, Jianwei

    2017-03-29

    Weakly electric fishes (Gymnotid and Mormyrid) use an electric field to communicate efficiently (termed electrocommunication) in the turbid waters of confined spaces where other communication modalities fail. Inspired by this biological phenomenon, we design an artificial electrocommunication system for small underwater robots and explore the capabilities of such an underwater robotic communication system. An analytical model for electrocommunication is derived to predict the effect of the key parameters such as electrode distance and emitter current of the system on the communication performance. According to this model, a low-dissipation, and small-sized electrocommunication system is proposed and integrated into a small robotic fish. We characterize the communication performance of the robot in still water, flowing water, water with obstacles and natural water conditions. The results show that underwater robots are able to communicate electrically at a speed of around 1 k baud within about 3 m with a low power consumption (less than 1 W). In addition, we demonstrate that two leader-follower robots successfully achieve motion synchronization through electrocommunication in the three-dimensional underwater space, indicating that this bio-inspired electrocommunication system is a promising setup for the interaction of small underwater robots.

  13. Feasibility of in situ beta ray measurements in underwater environment.

    Science.gov (United States)

    Park, Hye Min; Park, Ki Hyun; Kang, Sung Won; Joo, Koan Sik

    2017-09-01

    We describe an attempt at the development of an in situ detector for beta ray measurements in underwater environment. The prototype of the in situ detector is based on a CaF2: Eu scintillator using crystal light guide and Si photomultiplier. Tests were conducted using various reference sources for evaluating the linearity and stability of the detector in underwater environment. The system is simple and stable for long-term monitoring, and consumes low power. We show here an effective detection distance of 7 mm and a 2.273 MeV end-point energy spectrum of 90 Sr/ 90 Y when using the system underwater. The results demonstrate the feasibility of in situ beta ray measurements in underwater environment and can be applied for designing an in situ detector for radioactivity measurement in underwater environment. The in situ detector can also have other applications such as installation on the marine monitoring platform and quantitative analysis of radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Design and Evaluation Methods for Underwater Control Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Lin

    1996-12-31

    This thesis on underwater control systems is written with the designer in mind, assuming that the reader has some knowledge of control theory. It can be used as a text for undergraduate students and engineers. To help readers better understand the system they will be working with, the thesis is organised in a stepwise way. The reader will gain basic knowledge about underwater operations, equipment and control systems. Then the reader will be able to follow the steps to develop a required control system for an underwater equipment by first understanding the characteristics of the design problem, customer requirement, functional requirement, and possible solution, and then to present a mathematical model of the control problem. Having developed the concept, the thesis guides the reader to develop evaluation criteria and different ways to make the decision. The thesis gives an overview of how to achieve a successful design rather than giving the techniques for detailed control system design. Chapter 1 describes underwater operations and systems. Chapter 2 discusses issues of underwater control systems and control methods. Chapter 3 deals with design method and control systems theory, focusing on human-centered control. Chapter 4 discusses methods used to evaluate and rank products, and chapter 5 applies the methods to an example. 113 refs., 115 figs., 80 tabs.

  15. Oral communication in individuals with hearing impairment?considerations regarding attentional, cognitive and social resources

    OpenAIRE

    Lemke, Ulrike; Scherpiet, Sigrid

    2015-01-01

    Traditionally, audiology research has focused primarily on hearing and related disorders. In recent years, however, growing interest and insight has developed into the interaction of hearing and cognition. This applies to a person’s listening and speech comprehension ability and the neural realization thereof. The present perspective extends this view to oral communication, when two or more people interact in social context. Specifically, the impact of hearing impairment and cognitive changes...

  16. Training changes processing of speech cues in older adults with hearing loss

    OpenAIRE

    Anderson, Samira; White-Schwoch, Travis; Choi, Hee Jae; Kraus, Nina

    2013-01-01

    Aging results in a loss of sensory function, and the effects of hearing impairment can be especially devastating due to reduced communication ability. Older adults with hearing loss report that speech, especially in noisy backgrounds, is uncomfortably loud yet unclear. Hearing loss results in an unbalanced neural representation of speech: the slowly-varying envelope is enhanced, dominating representation in the auditory pathway and perceptual salience at the cost of the rapidly-varying fine s...

  17. Correlation between hearing loss and the results of the following questionnaires: Hearing Handicap Inventory for the Adults - Screening Version HHIA-S and Hearing Handicap Inventory for the Elderly - Screening Version - HHIE-S

    Directory of Open Access Journals (Sweden)

    Menegotto, Isabela Hoffmeister

    2011-07-01

    Full Text Available Introduction: The self-assessment questionnaires are useful to measure the emotional and social/transient consequences resulting from hearing loss, and they can be used in a wide range of situations in the clinical routine, such as auditory screening. Objective: Check the sensitivity and specificities of HHIA-S and HHIE-S questionnaires to identify a hearing loss and their usages in auditory screenings, as well as analyze the ability of these questionnaires to detect different degrees of hearing impairments in the studied people. Method: Retrospective study with 51 individuals aged between 18 and 88, who filled out the Hearing Handicap Inventory for Adults Screening Version - HHIA-S and Hearing Handicap Inventory for the Elderly Screening Version - HHIE-S questionnaires at the waiting room of the Brazilian Unified Health System (SUS's otorhinolaryngology infirmary. Results: The instruments showed a low sensitivity (47%, not identifying individuals with a hearing loss; however, they showed a high specificity (75%, accurately identifying individuals with no hearing disorder. Moreover, no significant association between the degree of hearing loss and the constraint degree for participation was found. Conclusion: the aforementioned questionnaires revealed a low sensitivity and a high specificity, proving to be ineffective for auditory screenings in a group with previous hearing complaints in addition to being unable to detect different types and degrees of hearing impairment.

  18. Dietary habits and hearing.

    Science.gov (United States)

    Rosenhall, Ulf; Idrizbegovic, Esma; Hederstierna, Christina; Rothenberg, Elisabet

    2015-02-01

    Abstract Objective: Study groups from three age cohorts of 70-75 year-olds were investigated to search for possible correlations between dietary habits and auditory function. A cross-sectional, epidemiological study. A total number of 524 people (275 women, 249 men) were recruited from three age cohorts. The study sample was representative of the general population. All participants answered a diet history and were tested with pure-tone audiometry. Eleven categories of food consumption were related to pure-tone averages of low-mid frequency hearing, and high frequency hearing. Two consistent correlations between diet and hearing were observed. One was a correlation between good hearing and a high consumption of fish in the male group. The other was a correlation between poor high frequency hearing and a high consumption of food rich in low molecular carbohydrates in both genders; a larger effect size was seen in females. The study indicates that diet is important for aural health in aging. According to this study fish is beneficial to hearing, whereas consumption of "junk food", rich in low molecular carbohydrates, is detrimental. Other correlations, e.g. between high consumption of antioxidants, were not demonstrated here, but cannot be excluded.

  19. Underwater wireless optical communications: From system-level demonstrations to channel modelling

    KAUST Repository

    Oubei, Hassan M.

    2018-01-09

    In this paper, we discuss about recent experimental advances in underwater wireless optical communications (UWOC) over various underwater channel water types using different modulation schemes as well as modelling and describing the statistical properties of turbulence-induced fading in underwater wireless optical channels using laser beam intensity fluctuations measurements.

  20. 76 FR 31233 - Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn, NY

    Science.gov (United States)

    2011-05-31

    ...-AA00 Safety Zone; Underwater Hazard, Gravesend Bay, Brooklyn, NY AGENCY: Coast Guard, DHS. ACTION... maritime public and safety of navigation from recently discovered underwater explosive hazards in Gravesend... published a notice of proposed rulemaking (NPRM) entitled ``Safety Zone; Underwater Hazard, Gravesend Bay...

  1. Efficient Weibull channel model for salinity induced turbulent underwater wireless optical communications

    KAUST Repository

    Oubei, Hassan M.

    2017-12-13

    Recent advances in underwater wireless optical communications necessitate a better understanding of the underwater channel. We propose the Weibull model to characterize the fading of salinity induced turbulent underwater wireless optical channels. The model shows an excellent agreement with the measured data under all channel conditions.

  2. Cantonese tone production performance of mainstream school children with hearing impairment.

    Science.gov (United States)

    Cheung, Karen K L; Lau, Ada H Y; Lam, Joffee H S; Lee, Kathy Y S

    2014-12-01

    This study investigated the Cantonese tone production ability of children with hearing impairment studying in mainstream schools. The participants were 87 Cantonese-speaking children with mild-to-profound degrees of hearing loss aged 5.92-13.58 in Hong Kong. Most of the children were fitted with hearing aids (n = 65); 17 of them had profound hearing impairment, one who had severe hearing loss had cochlear implantation, and four who had mild hearing loss were without any hearing device. The Hong Kong Cantonese Articulation Test was administered, and the tones produced were rated by two of the authors and a speech-language pathologist. Group effects of tones, hearing loss level, and also an interaction of the two were found to be significant. The children with profound hearing impairment performed significantly worse than most of the other children. Tone 1 was produced most accurately, whereas tone 6 productions were the poorest. No relationship was found between the number of years of mainstreaming and tone production ability. Tone production error pattern revealed that confusion patterns in tone perception coincided with those in production. Tones having a similar fundamental frequency (F0) at the onset also posed difficulty in tone production for children with hearing impairment.

  3. Decreased echolocation performance following high-frequency hearing loss in the false killer whale (Pseudorca crassidens).

    Science.gov (United States)

    Kloepper, L N; Nachtigall, P E; Gisiner, R; Breese, M

    2010-11-01

    Toothed whales and dolphins possess a hypertrophied auditory system that allows for the production and hearing of ultrasonic signals. Although the fossil record provides information on the evolution of the auditory structures found in extant odontocetes, it cannot provide information on the evolutionary pressures leading to the hypertrophied auditory system. Investigating the effect of hearing loss may provide evidence for the reason for the development of high-frequency hearing in echolocating animals by demonstrating how high-frequency hearing assists in the functioning echolocation system. The discrimination abilities of a false killer whale (Pseudorca crassidens) were measured prior to and after documented high-frequency hearing loss. In 1992, the subject had good hearing and could hear at frequencies up to 100 kHz. In 2008, the subject had lost hearing at frequencies above 40 kHz. First in 1992, and then again in 2008, the subject performed an identical echolocation task, discriminating between machined hollow aluminum cylinder targets of differing wall thickness. Performances were recorded for individual target differences and compared between both experimental years. Performances on individual targets dropped between 1992 and 2008, with a maximum performance reduction of 36.1%. These data indicate that, with a loss in high-frequency hearing, there was a concomitant reduction in echolocation discrimination ability, and suggest that the development of a hypertrophied auditory system capable of hearing at ultrasonic frequencies evolved in response to pressures for fine-scale echolocation discrimination.

  4. An Obstacle Recognizing Mechanism for Autonomous Underwater Vehicles Powered by Fuzzy Domain Ontology and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Zhen-Shu Mi

    2014-01-01

    Full Text Available The autonomous underwater vehicle (AUV and the problems associated with its safe navigation have been studied for the last two decades. The real-time underwater obstacle recognition procedure still has many complications associated with it and the issue becomes worse with vague sensor data. These problems can be coped with the merger of a robust classification mechanism and a domain knowledge acquisition technique. In this paper, we introduce a hybrid mechanism to recognize underwater obstacles for AUV based on fuzzy domain ontology and support vector machine (SVM. SVM is an efficient algorithm that was developed for recognizing 3D object in recent years and is a new generation learning system based on recent advances in statistical learning theory. The amalgamation of fuzzy domain ontology with SVM boosts the performance of the obstacle recognition module by providing the timely semantic domain information of the surrounding circumstances. Also the reasoning ability of the fuzzy domain ontology can expedite the obstacle avoidance process. In order to evaluate the performance of the system, we developed a prototype simulator based on OpenGL and VC++. We compared the outcomes of our proposed technique with backpropagation algorithm and classic SVM based techniques.

  5. DUMAND-II (deep underwater muon and neutrino detector) progress report

    Science.gov (United States)

    Young, Kenneth K.

    1995-07-01

    The DUMAND II detector will search for astronomical sources of high energy neutrinos. Successful deployment of the basic infrastructure, including the shore cable, the underwater junction box, and an environmental module was accomplished in December, 1993. One optical module string was also deployed and operated, logging data for about 10 hours. The underwater cable was connected to the shore station where we were able to successfully exercise system controls and log further environmental data. After this time, water leaking into the electronics control module for the deployed string disabled the string electrical system. The acquired data are consistent with the expected rate of downgoing muons, and our ability to reconstruct muons was demonstrated. The measured acoustical backgrounds are consistent with expectation, which should allow acoustical detection of nearby PeV particle cascades. The disabled string has been recovered and is undergoing repairs ashore. We have identified the source of the water leak and implemented additional testing and QC procedures to ensure no repetition in our next deployment. We will be ready to deploy three strings and begin continuous data taking in late 1994 or early 1995.

  6. Using Autonomous Underwater Vehicles as Sensor Platforms for Ice-Monitoring

    Directory of Open Access Journals (Sweden)

    Petter Norgren

    2014-10-01

    Full Text Available Due to the receding sea-ice extent in the Arctic, and the potentially large undiscovered petroleum resources present north of the Arctic circle, offshore activities in ice-infested waters are increasing. Due to the presence of drifting sea-ice and icebergs, ice management (IM becomes an important part of the offshore operation, and an important part of an IM system is the ability to reliably monitor the ice conditions. An autonomous underwater vehicle (AUV has a unique capability of high underwater spatial and temporal coverage, making it suitable for monitoring applications. Since the first Arctic AUV deployment in 1972, AUV technology has matured and has been used in complex under-ice operations. This paper motivates the use of AUVs as an ice-monitoring sensor platform. It discusses relevant sensor capabilities and challenges related to communication and navigation. This paper also presents experiences from a field campaign that took place in Ny-Aalesund at Svalbard in January 2014, where a REMUS 100 AUV was used for sea-floor mapping and collection of oceanographic parameters. Based on this, we discuss the experiences related to using AUVs for ice-monitoring. We conclude that AUVs are highly applicable for ice-monitoring, but further research is needed.

  7. Acoustic Trauma - Hearing Loss in Teenagers

    Science.gov (United States)

    ... I Can Hear It, It's Too Loud: Earbuds & Teen Hearing Loss Page Content ​Many parents will agree ... hearing loss." Recommended Hearing Screenings for Older Children & Teens Kids should be screened at three ages: 11- ...

  8. Parenting stress and social support in hearing mothers of deaf and hearing children: a longitudinal study.

    Science.gov (United States)

    Lederberg, Amy R; Golbach, Traci

    2002-01-01

    This longitudinal study investigated the impact of child deafness on mothers' stress, size of social networks, and satisfaction with social support. Twenty-three hearing mothers of deaf children and 23 hearing mothers of hearing children completed a series of self-report questionnaires when their children were 22 months, 3, and 4 years old. When children were 22 months, more mothers of deaf children reported pessimism about their children's achieving self-sufficiency and concerns about their children's communication abilities than did mothers of hearing children. When their children were 3 and 4 years old, mothers of deaf and hearing children did not differ in their reports of general parenting stress, as measured by the Parenting Stress Index (PSI). Likewise, mothers' ratings of satisfaction with social support were not affected by child deafness, nor did they change developmentally. Mothers of deaf and hearing children did differ in the types of support networks utilized. Mothers of deaf 22-month-olds reported significantly larger professional support networks, while mothers of hearing children reported significantly larger general support networks across all child ages. Mothers' feelings of stress and satisfaction with social support were very stable across the 2 years examined. The results suggest that most mothers of deaf children do not feel a high level of general parenting stress or dissatisfaction with their lives and support networks. However, mothers of deaf children are likely to feel stress in areas specific to deafness. In addition, because parenting stress was highly stable, special efforts should be made to intervene when mothers of deaf children are expressing high levels of stress.

  9. Chaos-Based Underwater Communication With Arbitrary Transducers and Bandwidth

    Directory of Open Access Journals (Sweden)

    Chao Bai

    2018-01-01

    Full Text Available In this work, an enhanced differential chaos shift keying (DCSK, based on a first order hybrid chaotic system, is being proposed for a high reliability underwater acoustic communication system. It can be integrated into systems that use standard existing transducers. We show that a coherent operation between the received signal and the time reversal of the basis function in a first order hybrid chaotic system maximizes the signal to noise ratio at the receiver. Concurrently, DCSK configuration is used to resist the distortion caused by the complex underwater acoustic channel. Our simulation results show that the proposed method has lower bit error rate (BER. In addition, it shows higher communication reliability over underwater acoustic channel as compared to the conventional DCSK using logistic map and its variant forms such as Correlation Delay Shift Keying (CDSK, Phase-Separate DCSK (PS-DCSK, High Efficiency DCSK (HE-DCSK, and Reference Modulated DCSK (RM-DCSK.

  10. Underwater video enhancement using multi-camera super-resolution

    Science.gov (United States)

    Quevedo, E.; Delory, E.; Callicó, G. M.; Tobajas, F.; Sarmiento, R.

    2017-12-01

    Image spatial resolution is critical in several fields such as medicine, communications or satellite, and underwater applications. While a large variety of techniques for image restoration and enhancement has been proposed in the literature, this paper focuses on a novel Super-Resolution fusion algorithm based on a Multi-Camera environment that permits to enhance the quality of underwater video sequences without significantly increasing computation. In order to compare the quality enhancement, two objective quality metrics have been used: PSNR (Peak Signal-to-Noise Ratio) and the SSIM (Structural SIMilarity) index. Results have shown that the proposed method enhances the objective quality of several underwater sequences, avoiding the appearance of undesirable artifacts, with respect to basic fusion Super-Resolution algorithms.

  11. The Research of Optical Turbulence Model in Underwater Imaging System

    Directory of Open Access Journals (Sweden)

    Liying Sun

    2014-01-01

    Full Text Available In order to research the effect of turbulence on underwater imaging system and image restoration, the underwater turbulence model is simulated by computer fluid dynamics. This model is obtained in different underwater turbulence intensity, which contains the pressure data that influences refractive index distribution. When the pressure value is conversed to refractive index, the refractive index distribution can be received with the refraction formula. In the condition of same turbulent intensity, the distribution of refractive index presents gradient in the whole region, with disorder and mutations in the local region. With the turbulence intensity increase, the holistic variation of the refractive index in the image is larger, and the refractive index change more tempestuously in the local region. All the above are illustrated by the simulation results with he ray tracing method and turbulent refractive index model. According to different turbulence intensity analysis, it is proved that turbulence causes image distortion and increases noise.

  12. Underwater Imaging Using a 1 × 16 CMUT Linear Array.

    Science.gov (United States)

    Zhang, Rui; Zhang, Wendong; He, Changde; Zhang, Yongmei; Song, Jinlong; Xue, Chenyang

    2016-03-01

    A 1 × 16 capacitive micro-machined ultrasonic transducer linear array was designed, fabricated, and tested for underwater imaging in the low frequency range. The linear array was fabricated using Si-SOI bonding techniques. Underwater transmission performance was tested in a water tank, and the array has a resonant frequency of 700 kHz, with pressure amplitude 182 dB (μPa·m/V) at 1 m. The -3 dB main beam width of the designed dense linear array is approximately 5 degrees. Synthetic aperture focusing technique was applied to improve the resolution of reconstructed images, with promising results. Thus, the proposed array was shown to be suitable for underwater imaging applications.

  13. Underwater Imaging Using a 1 × 16 CMUT Linear Array

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2016-03-01

    Full Text Available A 1 × 16 capacitive micro-machined ultrasonic transducer linear array was designed, fabricated, and tested for underwater imaging in the low frequency range. The linear array was fabricated using Si-SOI bonding techniques. Underwater transmission performance was tested in a water tank, and the array has a resonant frequency of 700 kHz, with pressure amplitude 182 dB (μPa·m/V at 1 m. The −3 dB main beam width of the designed dense linear array is approximately 5 degrees. Synthetic aperture focusing technique was applied to improve the resolution of reconstructed images, with promising results. Thus, the proposed array was shown to be suitable for underwater imaging applications.

  14. H∞ control for path tracking of autonomous underwater vehicle motion

    Directory of Open Access Journals (Sweden)

    Lin-Lin Wang

    2015-05-01

    Full Text Available In order to simplify the design of path tracking controller and solve the problem relating to nonlinear dynamic model of autonomous underwater vehicle motion planning, feedback linearization method is first adopted to transform the nonlinear dynamic model into an equivalent pseudo-linear dynamic model in horizontal coordinates. Then considering wave disturbance effect, mixed-sensitivity method of H∞ robust control is applied to design state-feedback controller for this equivalent dynamic model. Finally, control law of pseudo-linear dynamic model is transformed into state (surge velocity and yaw angular rate tracking control law of nonlinear dynamic model through inverse coordinate transformation. Simulation indicates that autonomous underwater vehicle path tracking is successfully implemented with this proposed method, and the influence of parameter variation in autonomous underwater vehicle dynamic model on its tracking performance is reduced by H∞ controller. All the results show that the method proposed in this article is effective and feasible.

  15. A simple inexpensive method for estimating underwater weight.

    Science.gov (United States)

    Thomas, T. R.; Cook, P. L.

    1978-01-01

    A description is given of a simple, inexpensive and versatile method for estimating underwater weight. The use of a portable stock tank allows the determination of % Fat by underwater weighing without requiring a swimming pool, built-in tank, or special facility. Twenty-eight college students were weighed on two separate testing sessions 24-48 hours apart. Ten trials were performed at each session. The mean of the last five trials was used in determining underwater weight. The test-retest reliability coefficient was high, r = 0.98, and most of the successive trial correlations were above 0.99. The mean % Fat for the women (N = 9) was 22.2 +/- 5.9 and for the men (N = 19) was 13.7 +/- 5.1. Images Figure 1 PMID:630178

  16. An underwater optical wireless communication system based on LED source

    Science.gov (United States)

    Rao, Jionghui; Wei, Wei; Wang, Feng; Zhang, Xiaohui

    2011-11-01

    Compared with other communication methods, optical wireless communication (OWC) holds the merits of higher transmitting rate and sufficient secrecy. So it is an efficacious communicating measure for data transmitting between underwater carriers. However, due to the water attenuation and the transmitter & the receiver (TX/RX) collimation, this application is restrained in underwater mobile carriers. A prototype for underwater OWC was developed, in which a high-powered green LED array was used as the light source which partly raveled the TX/RX collimation out. A small pumped-multiple-tube (PMT) was used as the detector to increase the communicating range, and FPGA chips were employed to code and decode the communicating data. The data rate of the prototype approached to 4 Mb/s at 8.4m and 1 Mb/s at 22m where voice and Morse communications were achieved in a scope of 30 degree TX/RX angle.

  17. Broadband focusing of underwater sound using a transparent pentamode lens.

    Science.gov (United States)

    Su, Xiaoshi; Norris, Andrew N; Cushing, Colby W; Haberman, Michael R; Wilson, Preston S

    2017-06-01

    An inhomogeneous acoustic metamaterial lens based on spatial variation of refractive index for broadband focusing of underwater sound is reported. The index gradient follows a modified hyperbolic secant profile designed to reduce aberration and suppress side lobes. The gradient index (GRIN) lens is comprised of transversely isotropic hexagonal microstructures with tunable quasi-static bulk modulus and mass density. In addition, the unit cells are impedance-matched to water and have in-plane shear modulus negligible compared to the effective bulk modulus. The flat GRIN lens is fabricated by cutting hexagonal centimeter scale hollow microstructures in aluminum plates, which are then stacked and sealed from the exterior water. Broadband focusing effects are observed within the homogenization regime of the lattice in both finite element simulations and underwater measurements (20-40 kHz). This design approach has potential applications in medical ultrasound imaging and underwater acoustic communications.

  18. Underwater Acoustic Communication Quality Evaluation Model Based on USV

    Directory of Open Access Journals (Sweden)

    Zhichao Lv

    2018-01-01

    Full Text Available The unmanned surface vehicle (USV integrated with acoustic modems has some advantages such as easy integration, rapid placement, and low cost, which becomes a kind of selective novel node in the underwater acoustic (UWA communication network and a kind of underwater or overwater communication relay as well. However, it is difficult to ensure the communication quality among the nodes on the network due to the random underwater acoustic channel, the severe marine environment, and the complex mobile node system. Aiming to model the communication characteristics of the USV, the multipath effect and Doppler effect are main concerns for the UWA communication in this paper, so that the ray beam method is utilized, the channel transmission function and the channel gain are obtained, and the mobile communication quality evaluation model is built. The simulation and lake experiments verify that the built mobile UWA communication quality evaluation model on USV can provide preference and technique support for USV applications.

  19. Course Outline for a SCUBA Diving Speciality "UNDERWATER Survey DIVER"

    Science.gov (United States)

    Papadimitriou, K.

    2015-04-01

    The purpose of this paper is to outline a course for the training of divers with a special interest in underwater surveying (e.g. surveyors, archaeologists, biologists, geologists, photographers/videographers). This outline presents: i) the Courses' Standards ii) the Learning Objectives for the related Knowledge Development, iii) the Skills that have to be conducted, iv) the Performance Requirements for the students and v) the Open Water Considerations for the Training Dives. It is expected that the resulting course outline will be used as a reference for the training of certified divers who want to become underwater surveyors, providing them basic knowledge and skills to survey adequate data for the detailed documentation of submerged features. Moreover the combination of knowledge (what) and the skills (how) that are presented during the proposed course attempt to define a protocol for the recording of underwater features in favor of mapping and 3D modeling.

  20. Underwater Time Service and Synchronization Based on Time Reversal Technique

    Science.gov (United States)

    Lu, Hao; Wang, Hai-bin; Aissa-El-Bey, Abdeldjalil; Pyndiah, Ramesh

    2010-09-01

    Real time service and synchronization are very important to many underwater systems. But the time service and synchronization in existence cannot work well due to the multi-path propagation and random phase fluctuation of signals in the ocean channel. The time reversal mirror technique can realize energy concentration through self-matching of the ocean channel and has very good spatial and temporal focusing properties. Based on the TRM technique, we present the Time Reversal Mirror Real Time service and synchronization (TRMRT) method which can bypass the processing of multi-path on the server side and reduce multi-path contamination on the client side. So TRMRT can improve the accuracy of time service. Furthermore, as an efficient and precise method of time service, TRMRT could be widely used in underwater exploration activities and underwater navigation and positioning systems.

  1. Optimal Node Placement in Underwater Wireless Sensor Networks

    KAUST Repository

    Felamban, M.

    2013-03-25

    Wireless Sensor Networks (WSN) are expected to play a vital role in the exploration and monitoring of underwater areas which are not easily reachable by humans. However, underwater communication via acoustic waves is subject to several performance limitations that are very different from those used for terresstrial networks. In this paper, we investigate node placement for building an initial underwater WSN infrastructure. We formulate this problem as a nonlinear mathematical program with the objective of minimizing the total transmission loss under a given number of sensor nodes and targeted coverage volume. The obtained solution is the location of each node represented via a truncated octahedron to fill out the 3D space. Experiments are conducted to verify the proposed formulation, which is solved using Matlab optimization tool. Simulation is also conducted using an ns-3 simulator, and the simulation results are consistent with the obtained results from mathematical model with less than 10% error.

  2. A potential flow based flight simulator for an underwater glider

    Science.gov (United States)

    Phoemsapthawee, Surasak; Le Boulluec, Marc; Laurens, Jean-Marc; Deniset, François

    2013-03-01

    Underwater gliders are recent innovative types of autonomous underwater vehicles (AUVs) used in ocean exploration and observation. They adjust their buoyancy to dive and to return to the ocean surface. During the change of altitude, they use the hydrodynamic forces developed by their wings to move forward. Their flights are controlled by changing the position of their centers of gravity and their buoyancy to adjust their trim and heel angles. For better flight control, the understanding of the hydrodynamic behavior and the flight mechanics of the underwater glider is necessary. A 6-DOF motion simulator is coupled with an unsteady potential flow model for this purpose. In some specific cases, the numerical study demonstrates that an inappropriate stabilizer dimension can cause counter-steering behavior. The simulator can be used to improve the automatic flight control. It can also be used for the hydrodynamic design optimization of the devices.

  3. Underwater Signal Modeling for Subsurface Classification Using Computational Intelligence.

    Science.gov (United States)

    Setayeshi, Saeed

    In the thesis a method for underwater layered media (UWLM) modeling is proposed, and a simple nonlinear structure for implementation of this model based on the behaviour of its characteristics and the propagation of the acoustic signal in the media accounting for attenuation effects is designed. The model that responds to the acoustic input is employed to test the artificial intelligence classifiers ability. Neural network models, the basic principles of the back-propagation algorithm, and the Hopfield model of associative memories are reviewed, and they are employed to use min-max amplitude ranges of a reflected signal of UWLM based on attenuation effects, to define the classes of the synthetic data, detect its peak features and estimate parameters of the media. It has been found that there is a correlation between the number of layers in the media and the optimum number of nodes in the hidden layer of the neural networks. The integration of the result of the neural networks that classify and detect underwater layered media acoustic signals based on attenuation effects to prove the correspondence between the peak points and decay values has introduced a powerful tool for UWLM identification. The methods appear to have applications in replacing original system, for parameter estimation and output prediction in system identification by the proposed networks. The results of computerized simulation of the UWLM modeling in conjunction with the proposed neural networks training process are given. Fuzzy sets is an idea that allows representing and manipulating inexact concepts, fuzzy min-max pattern classification method, and the learning and recalling algorithms for fuzzy neural networks implementation is explained in this thesis. A fuzzy neural network that uses peak amplitude ranges to define classes is proposed and evaluated for UWLM pattern recognition. It is demonstrated to be able to classify the layered media data sets, and can distinguish between the peak points

  4. Underwater Visual Computing: The Grand Challenge Just around the Corner.

    Science.gov (United States)

    von Lukas, Uwe Freiherr

    2016-01-01

    Visual computing technologies have traditionally been developed for conventional setups where air is the surrounding medium for the user, the display, and/or the camera. However, given mankind's increasingly need to rely on the oceans to solve the problems of future generations (such as offshore oil and gas, renewable energies, and marine mineral resources), there is a growing need for mixed-reality applications for use in water. This article highlights the various research challenges when changing the medium from air to water, introduces the concept of underwater mixed environments, and presents recent developments in underwater visual computing applications.

  5. Ancient Dwarka: Study based on recent underwater archaeological investigations

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Tripati, S.

    -1 Migration & Diffusion, Vol. 6, Issue Number 21, 2005 ANCIENT DWARKA: STUDY BASED ON RECENT UNDERWATER ARCHAEOLOGICAL INVESTIGATIONS by A.S. Gaur, Sundaresh and Sila Tripati Summary Dwarka, one of the best-studied underwater sites in India, has...). Dwarka has been the attraction for historians since the beginning of the 20th century. The ancient town Dwarka has been described as 56 Migration & Diffusion, Vol 6, Issue Number 21, 2005 Fig.l: Dwarka is headquarter of the Okhamandal taluka in Jamnagar...

  6. Underwater Shock Response Analysis of a Floating Vessel

    Directory of Open Access Journals (Sweden)

    J.E. van Aanhold

    1998-01-01

    Full Text Available The response of a surface vessel to underwater shock has been calculated using an explicit finite element analysis. The analysis model is two-dimensional and contains the floating steel structure, a large surrounding water volume and the free surface. The underwater shock is applied in the form of a plane shock wave and cavitation is considered in the analysis. Advanced computer graphics, in particular video animations, provide a powerful and indispensable means for the presentation and evaluation of the analysis results.

  7. Factors Affecting Sentence-in-Noise Recognition for Normal Hearing Listeners and Listeners with Hearing Loss.

    Science.gov (United States)

    Hwang, Jung Sun; Kim, Kyung Hyun; Lee, Jae Hee

    2017-07-01

    Despite amplified speech, listeners with hearing loss often report more difficulties understanding speech in background noise compared to normalhearing listeners. Various factors such as deteriorated hearing sensitivity, age, suprathreshold temporal resolution, and reduced capacity of working memory and attention can attribute to their sentence-in-noise problems. The present study aims to determine a primary explanatory factor for sentence-in-noise recognition difficulties in adults with or without hearing loss. Forty normal-hearing (NH) listeners (23-73 years) and thirty-four hearing-impaired (HI) listeners (24-80 years) participated for experimental testing. For both NH and HI group, the younger, middle-aged, older listeners were included. The sentence recognition score in noise was measured at 0 dB signal-to-noise ratio. The ability of temporal resolution was evaluated by gap detection performance using the Gaps-In-Noise test. Listeners' short-term auditory working memory span was measured by forward and backward digit spans. Overall, the HI listeners' sentence-in-noise recognition, temporal resolution abilities, and digit forward and backward spans were poorer compared to the NH listeners. Both NH and HI listeners had a substantial variability in performance. For NH listeners, only the digit backward span explained a small proportion of the variance in their sentence-in-noise performance. For the HI listeners, all the performance was influenced by age, and their sentence-in-noise difficulties were associated with various factors such as high-frequency hearing sensitivity, suprathreshold temporal resolution abilities, and working memory span. For the HI listeners, the critical predictors of the sentence-in-noise performance were composite measures of peripheral hearing sensitivity and suprathreshold temporal resolution abilities. The primary explanatory factors for the sentence-in-noise recognition performance differ between NH and HI listeners. Factors

  8. How Students with Hearing Impairments: Can Learn and Flourish in Your Music Classroom

    Science.gov (United States)

    Butler, Maureen

    2004-01-01

    Activities in music class allow students, especially students with hearing impairments, to explore new means of expression and to enhance existing ones. Additional benefits may include increases in auditory awareness, cognitive ability, attention span, memory recall, and vocabulary. Students with hearing impairments can learn and flourish in music…

  9. The Impact of Verbal Capacity on Theory of Mind in Deaf and Hard of Hearing Children

    Science.gov (United States)

    Levrez, Clovis; Bourdin, Beatrice; Le Driant, Barbara; Forgeot d'Arc, Baudouin; Vandromme, Luc

    2012-01-01

    Even when they have good language skills, many children with hearing loss lag several years behind hearing children in the ability to grasp beliefs of others. The researchers sought to determine whether this lag results from difficulty with the verbal demands of tasks or from conceptual delays. The researchers related children's performance on a…

  10. Concern for Others: A Study on Empathy in Toddlers with Moderate Hearing Loss

    Science.gov (United States)

    Dirks, Evelien; Ketelaar, Lizet; van der Zee, Rosanne; Netten, Anouk P.; Frijns, Johan H. M.; Rieffe, Carolien

    2017-01-01

    Empathy, the ability to feel the emotions of others and respond affectively to these emotions, is an important factor in the development of social competence. The purpose of this study was to examine empathy levels in toddlers with moderate hearing loss (MHL) compared to toddlers with no hearing loss (nHL), and to explore the relation between…

  11. Psychosocial Development in 5-Year-Old Children With Hearing Loss Using Hearing Aids or Cochlear Implants

    Science.gov (United States)

    Ching, Teresa Y. C.; Cupples, Linda; Button, Laura; Leigh, Greg; Marnane, Vivienne; Whitfield, Jessica; Gunnourie, Miriam; Martin, Louise

    2017-01-01

    This article reports on the psychosocial development and factors influencing outcomes of 5-year-old children with cochlear implants (CIs) or hearing aids (HAs). It further examines differences between children with CIs and HAs with similar levels of hearing loss. Data were collected as part of the Longitudinal Outcomes of Children with Hearing Impairment study—a prospective, population-based study. Parents/caregivers of children completed the Strengths and Difficulties Questionnaire (n = 333), the Social Skills subscale from the Child Development Inventory (n = 317), and questionnaires on functional auditory behavior (Parents’ Evaluation of Aural/oral performance of Children), and demographics. Children completed assessments of nonverbal cognitive ability (Wechsler Non-verbal Scale of Ability) and language (Preschool Language Scale - fourth edition). On average, parent-rated Strengths and Difficulties Questionnaire scores on emotional or behavioral difficulties were within 1 SD of the normative mean; however, Child Development Inventory scores on social skills were more than 1 SD below the norm. Children with severe-to-profound hearing losses using HAs had significantly more behavioral problems than children with CIs. Regression analyses showed that non-verbal cognitive ability, language, and functional auditory behavior were significantly associated with psychosocial outcomes for children with HAs, whereas outcomes for children with CIs were associated with functional auditory behavior and the presence of additional disabilities. Age at hearing intervention, severity of hearing loss, and communication mode were not associated with outcomes. The results suggest that even children who develop good language ability with the help of a HA or CI may have psychosocial problems if they exhibit difficulties with listening and communicating in everyday environments. The findings have implications for developing interventions for young children with hearing

  12. Psychosocial Development in 5-Year-Old Children With Hearing Loss Using Hearing Aids or Cochlear Implants.

    Science.gov (United States)

    Wong, Cara L; Ching, Teresa Y C; Cupples, Linda; Button, Laura; Leigh, Greg; Marnane, Vivienne; Whitfield, Jessica; Gunnourie, Miriam; Martin, Louise

    2017-01-01

    This article reports on the psychosocial development and factors influencing outcomes of 5-year-old children with cochlear implants (CIs) or hearing aids (HAs). It further examines differences between children with CIs and HAs with similar levels of hearing loss. Data were collected as part of the Longitudinal Outcomes of Children with Hearing Impairment study-a prospective, population-based study. Parents/caregivers of children completed the Strengths and Difficulties Questionnaire ( n = 333), the Social Skills subscale from the Child Development Inventory ( n = 317), and questionnaires on functional auditory behavior (Parents' Evaluation of Aural/oral performance of Children), and demographics. Children completed assessments of nonverbal cognitive ability (Wechsler Non-verbal Scale of Ability) and language (Preschool Language Scale - fourth edition). On average, parent-rated Strengths and Difficulties Questionnaire scores on emotional or behavioral difficulties were within 1 SD of the normative mean; however, Child Development Inventory scores on social skills were more than 1 SD below the norm. Children with severe-to-profound hearing losses using HAs had significantly more behavioral problems than children with CIs. Regression analyses showed that non-verbal cognitive ability, language, and functional auditory behavior were significantly associated with psychosocial outcomes for children with HAs, whereas outcomes for children with CIs were associated with functional auditory behavior and the presence of additional disabilities. Age at hearing intervention, severity of hearing loss, and communication mode were not associated with outcomes. The results suggest that even children who develop good language ability with the help of a HA or CI may have psychosocial problems if they exhibit difficulties with listening and communicating in everyday environments. The findings have implications for developing interventions for young children with hearing

  13. Underwater maintenance guide: A guide to diving and remotely operated vehicle operations for nuclear maintenance personnel

    International Nuclear Information System (INIS)

    Jenco, J.

    1990-12-01

    This Underwater Maintenance Guide has been developed to provide utility plant personnel with a single-source reference to underwater services. These services, which include both manned diving and remotely-operated vehicle operations, are required to perform certain underwater maintenance functions at nuclear power generating stations. This Guide provides an introduction to those underwater services and their general operations, as well as overviews of specific work tasks which have been identified thus far. This information is intended to familiarize utility maintenance personnel with the general scope and capabilities of underwater services, without encroaching upon the contractor's flexibility to develop responses to individual maintenance tasks

  14. Hearing Protection and Hearing Symptoms in Danish Symphony Orchestras

    DEFF Research Database (Denmark)

    Laitinen, Heli; Poulsen, Torben

    2006-01-01

    A study about hearing protectors, problems involving hearing protector usage, hearing problems and working surroundings of classical musicians was made in three Danish symphony orchestras. The questionnaire used in the study was based on a previous study, a study made in Sweden to rock musicians,...

  15. Comparative analysis of endurance of not hearing and hearing students

    Directory of Open Access Journals (Sweden)

    Iwańska Dagmara

    2013-11-01

    Full Text Available Study aim: Sport participation is important for deaf children, as participants experience physical, psychological and social benefits [23]. This study is a summary of four year’s researches on the endurance level of deaf and well hearing girls and boys. The aim of this study was to compare endurance of not hearing and hearing students.

  16. Pediatric hearing aid use: parent-reported challenges.

    Science.gov (United States)

    Muñoz, Karen; Olson, Whitney A; Twohig, Michael P; Preston, Elizabeth; Blaiser, Kristina; White, Karl R

    2015-01-01

    The aim of this study was to investigate parent-reported challenges related to hearing aid management and parental psychosocial characteristics during the first 3 years of the child's life. Using a cross-sectional survey design, surveys were distributed to parents of children with hearing loss via state Early Intervention programs in Utah and Indiana. Packets contained one family demographic form and two sets of three questionnaires to obtain responses from mothers and fathers separately: the Parent Hearing Aid Management Inventory explored parent access to information, parent confidence in performing skills, expectations, communication with the audiologist, and hearing aid use challenges. The Acceptance and Action Questionnaire measured psychological flexibility, experiential avoidance, and internal thought processes that can affect problem-solving ability and decrease an individual's ability to take value-based actions. The Patient Health Questionnaire identified symptoms of depression. Thirty-seven families completed questionnaires (35 mothers and 20 fathers). Most responses were parents of toddlers (M = 22 months) who had been wearing binaural hearing aids for an average of 15 months. Both mothers and fathers reported that even though the amount of information they received was overwhelming, most (84%) preferred to have all the information at the beginning, rather than to receive it over an extended time period. Parents reported an array of challenges related to hearing aid management, with the majority related to daily management, hearing aid use, and emotional adjustment. Sixty-six percent of parents reported an audiologist taught them how to complete a listening check using a stethoscope, however, only one-third reported doing a daily hearing aid listening check. Both mothers and fathers reported a wide range of variability in their confidence in performing activities related to hearing aid management, and most reported minimal confidence in their ability to

  17. Newborn hearing screening.

    Science.gov (United States)

    Stewart, D L; Pearlman, A

    1994-11-01

    Congenital deafness is a relatively common problem with an incidence of 1/300 to 1/1000. Most states have no mass screening program for hearing loss, but the state of Kentucky compiles a High Risk Registry which is a historical survey of parents relating to risk factors for hearing loss. Unfortunately this survey can miss 50% of those who have a hearing deficit. If not detected prior to discharge, there is often a delay in diagnosis of deafness which prevents early intervention. We report 2 years' experience at Kosair Children's Hospital where 1,987 infants admitted to well baby, intermediate, or intensive care nurseries were screened using the ALGO-1 screener (Natus Medical Inc, Foster City, CA) which is a modified auditory brain stem evoked response (ABR). Our screening of this population led to an 11% incidence of referral for complete audiological evaluation. There were no significant complications. Forty-eight infants were found to have nonspecified, sensorineural, or conductive hearing loss. The positive predictive value of the test was 96%. Therefore, we feel that the use of the modified ABR in the newborn is a timely, cost efficient method of screening for hearing loss and should be used for mass screening of all newborns.

  18. Hearing speech in music

    Directory of Open Access Journals (Sweden)

    Seth-Reino Ekström

    2011-01-01

    Full Text Available The masking effect of a piano composition, played at different speeds and in different octaves, on speech-perception thresholds was investigated in 15 normal-hearing and 14 moderately-hearing-impaired subjects. Running speech (just follow conversation, JFC testing and use of hearing aids increased the everyday validity of the findings. A comparison was made with standard audiometric noises [International Collegium of Rehabilitative Audiology (ICRA noise and speech spectrum-filtered noise (SPN]. All masking sounds, music or noise, were presented at the same equivalent sound level (50 dBA. The results showed a significant effect of piano performance speed and octave (P<.01. Low octave and fast tempo had the largest effect; and high octave and slow tempo, the smallest. Music had a lower masking effect than did ICRA noise with two or six speakers at normal vocal effort (P<.01 and SPN (P<.05. Subjects with hearing loss had higher masked thresholds than the normal-hearing subjects (P<.01, but there were smaller differences between masking conditions (P<.01. It is pointed out that music offers an interesting opportunity for studying masking under realistic conditions, where spectral and temporal features can be varied independently. The results have implications for composing music with vocal parts, designing acoustic environments and creating a balance between speech perception and privacy in social settings.

  19. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... Programs Recommendations & Guidelines Free Materials Parent’s Guide Multimedia & Tools My ... Hearing plays an essential role in communication, speech and language development, and learning. Even a small amount of hearing loss can ...

  20. Noise and Hearing Loss Prevention

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . NOISE AND HEARING LOSS PREVENTION Language: English (US) Español ( ... when hazardous noise levels cannot be adequately reduced. Noise and Hearing Loss on the NIOSH Science Blog ...

  1. Single-sided deafness & directional hearing: contribution of spectral cues and high-frequency hearing loss in the hearing ear

    Directory of Open Access Journals (Sweden)

    Martijn Johannes Hermanus Agterberg

    2014-07-01

    Full Text Available Direction-specific interactions of sound waves with the head, torso and pinna provide unique spectral-shape cues that are used for the localization of sounds in the vertical plane, whereas horizontal sound localization is based primarily on the processing of binaural acoustic differences in arrival time (interaural time differences, or ITDs and sound level (interaural level differences, or ILDs. Because the binaural sound-localization cues are absent in listeners with total single-sided deafness (SSD, their ability to localize sound is heavily impaired. However, some studies have reported that SSD listeners are able, to some extent, to localize sound sources in azimuth, although the underlying mechanisms used for localization are unclear. To investigate whether SSD listeners rely on monaural pinna-induced spectral-shape cues of their hearing ear for directional hearing, we investigated localization performance for low-pass filtered (LP, 3 kHz and broadband (BB, 0.5 – 20 kHz noises in the two-dimensional frontal hemifield. We tested whether localization performance of SSD listeners further deteriorated when the pinna cavities of their hearing ear were filled with a mold that disrupted their spectral-shape cues. To remove the potential use of perceived sound level as an invalid azimuth cue, we randomly varied stimulus presentation levels over a broad range (45-65 dB SPL. Several listeners with SSD could localize HP and BB sound sources in the horizontal plane, but inter-subject variability was considerable. Localization performance of these listeners strongly reduced after diminishing of their spectral pinna-cues. We further show that inter-subject variability of SSD can be explained to a large extent by the severity of high-frequency hearing loss in their hearing ear.

  2. The Improved Kriging Interpolation Algorithm for Local Underwater Terrain Based on Fractal Compensation

    Directory of Open Access Journals (Sweden)

    Pengyun Chen

    2014-01-01

    Full Text Available The interpolation-reconstruction of local underwater terrain using the underwater digital terrain map (UDTM is an important step for building an underwater terrain matching unit and directly affects the accuracy of underwater terrain matching navigation. The Kriging method is often used in terrain interpolation, but, with this method, the local terrain features are often lost. Therefore, the accuracy cannot meet the requirements of practical application. Analysis of the geographical features is performed on the basis of the randomness and self-similarity of underwater terrain. We extract the fractal features of local underwater terrain with the fractal Brownian motion model, compensating for the possible errors of the Kriging method with fractal theory. We then put forward an improved Kriging interpolation method based on this fractal compensation. Interpolation-reconstruction tests show that the method can simulate the real underwater terrain features well and that it has good usability.

  3. Single underwater image enhancement based on color cast removal and visibility restoration

    Science.gov (United States)

    Li, Chongyi; Guo, Jichang; Wang, Bo; Cong, Runmin; Zhang, Yan; Wang, Jian

    2016-05-01

    Images taken under underwater condition usually have color cast and serious loss of contrast and visibility. Degraded underwater images are inconvenient for observation and analysis. In order to address these problems, an underwater image-enhancement method is proposed. A simple yet effective underwater image color cast removal algorithm is first presented based on the optimization theory. Then, based on the minimum information loss principle and inherent relationship of medium transmission maps of three color channels in an underwater image, an effective visibility restoration algorithm is proposed to recover visibility, contrast, and natural appearance of degraded underwater images. To evaluate the performance of the proposed method, qualitative comparison, quantitative comparison, and color accuracy test are conducted. Experimental results demonstrate that the proposed method can effectively remove color cast, improve contrast and visibility, and recover natural appearance of degraded underwater images. Additionally, the proposed method is comparable to and even better than several state-of-the-art methods.

  4. An Underwater Image Enhancement Algorithm for Environment Recognition and Robot Navigation

    Directory of Open Access Journals (Sweden)

    Kun Xie

    2018-03-01

    Full Text Available There are many tasks that require clear and easily recognizable images in the field of underwater robotics and marine science, such as underwater target detection and identification of robot navigation and obstacle avoidance. However, water turbidity makes the underwater image quality too low to recognize. This paper proposes the use of the dark channel prior model for underwater environment recognition, in which underwater reflection models are used to obtain enhanced images. The proposed approach achieves very good performance and multi-scene robustness by combining the dark channel prior model with the underwater diffuse model. The experimental results are given to show the effectiveness of the dark channel prior model in underwater scenarios.

  5. e-Health technologies for adult hearing screening

    Directory of Open Access Journals (Sweden)

    S. Stenfelt

    2011-03-01

    Full Text Available The development of hearing diagnosis methods and hearing screening methods are not isolated phenomena: they are intimately related to changes in the cultural background and to advances in fields of medicine and engineering. In the recent years, there has been a rapid evolution in the development of fast, easy and reliable techniques for lowcost hearing screening initiatives. Since adults and elderly people typically experience a reduced hearing ability in challenging listening situations [e.g., in background noise, in reverberation, or with competing speech (Pichora‑Fuller & Souza, 2003], these newly developed screening tests mainly rely on the recognition of speech stimuli in noise, so that the real experienced listening difficulties can be effectively targeted (Killion & Niquette, 2000. New tests based on the recognition of speech in noise are being developed on portable, battery- operated devices (see, for example, Paglialonga et al., 2011, or distributed diffusely using information and communication technologies. The evolutions of e-Health and telemedicine have shifted focus from patients coming to the hearing clinic for hearing health evaluation towards the possibility of evaluating the hearing status remotely at home. So far, two ways of distributing the hearing test have primarily been used: ordinary telephone networks (excluding mobile networks and the internet. When using the telephone network for hearing screening, the predominantly test is a speech-in-noise test often referred to as the digit triplet test where the subjects hearing status is evaluated as the speech-to-noise threshold for spoken digits. This test is today available in some ten countries in Europe, North America and Australia. The use of internet as testing platform allows several different types of hearing assessment tests such as questionnaires, different types of speech in noise tests, temporal gap detection, sound localization (minimum audible angle, and spectral

  6. Investigation of the actions taken by adults who failed a telephone-based hearing screen.

    Science.gov (United States)

    Meyer, Carly; Hickson, Louise; Khan, Asad; Hartley, David; Dillon, Harvey; Seymour, John

    2011-01-01

    Hearing impairment constitutes a highly prevalent chronic health condition among older adults worldwide which negatively impacts on communication and health-related quality of life. Irrespective of this, the majority of older adults do not seek professional help for hearing impairment and/or do not obtain hearing aids. Therefore, a new approach for detecting and promoting help-seeking for hearing impairment is needed. The purpose of this study was to investigate the actions taken by those who failed Telscreen, a telephone-based screening tool for hearing loss, and to increase our understanding of factors that influence taking action. A cohort of 193 participants (112 females, 81 males; age range 24-93 yr) who had failed Telscreen participated in a follow-up telephone interview 4 to 5 mo later. Participants were asked why they called Telscreen, about their hearing ability, their Telscreen result, and what action they had taken toward hearing rehabilitation. One outcome measure was identified: decision to seek professional help for hearing impairment (yes/no). Given that the outcome measure was dichotomized, a logistic regression model for binary outcomes was fitted to the data. Of the 193 participants who failed Telscreen, only 36% sought help from a range of sources (e.g., audiologist, hearing service or hearing aid provider, and family doctor). Results of the logistic regression analysis indicated that individuals who had considered hearing aids before calling Telscreen and/or who recalled their Telscreen result were significantly more likely to seek professional help for their hearing impairment. Nineteen participants who sought help for their hearing impairment had hearing aid fitting recommended to them. Eight participants had aid/s fitted, and of these, six reported a successful outcome. For every 100 individuals who fail a hearing screening, only 36 seek help. Of these 36 individuals who take some action, 13 are recommended hearing aids, approximately half of

  7. Description, Normative Data, and Utility of the Hearing Aid Skills and Knowledge Test.

    Science.gov (United States)

    Saunders, Gabrielle H; Morse-Fortier, Charlotte; McDermott, Daniel J; Vachhani, Jay J; Grush, Leslie D; Griest, Susan; Lewis, M Samantha

    2018-03-01

    The ability to manage hearing aids is crucial for successful outcomes and for maintaining hearing aid use. It is therefore important to have a tool that can effectively identify which hearing aid management skills are lacking so that the audiologist can provide additional education and training on that skill. Such a tool can also provide useful quantitative data for researchers. To collect normative data (Experiment 1) and assess inter- and intrarater reliability (Experiment 2) for a hearing aid management assessment tool known as the Hearing Aid Skills and Knowledge (HASK) test. Two hundred thirty-six new hearing aid users recruited from the VA Portland Health Care System and 126 experienced hearing aid users recruited from the local Portland community participated in Experiment 1. The veteran participants were taking part in a larger hearing aid study, and the community participants were recruited at community events that took place around Portland, OR. Three clinical audiologists and two AuD students completing their fourth year externship participated in Experiment 2. In Experiment 1, HASK data were collected from the new hearing aid users at 4-8 wk and 6-8 mo after the fitting of their first pair of hearing aids, and from experienced users on a single occasion. In addition, self-reported hearing aid use, benefit, and satisfaction were assessed for all participants. The audiologists/students in Experiment 2 watched and independently scored videos of six individuals completing the HASK. Intraclass correlation coefficients (ICCs) across audiologists were computed for HASK scores. Three audiologists/students rated at least one video on two occasions to provide interrater reliability data. Mean performance on the HASK was about 70% for knowledge and 80% for skills for both the new and experienced hearing aid users. Performance did not change among the new users between the 4-8 wk and 6-8 mo administration. The specific skills lacking were associated with advanced

  8. Congenital sensorineural hearing loss

    International Nuclear Information System (INIS)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-01-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems

  9. Congenital sensorineural hearing loss

    Energy Technology Data Exchange (ETDEWEB)

    Mafee, M.F.; Selis, J.E.; Yannias, D.A.; Valvassori, G.E.; Pruzansky, S.; Applebaum, E.L.; Capek, V.

    1984-02-01

    The ears of 47 selected patients with congenital sensorineural hearing loss were examined with complex-motion tomography. The patients were divided into 3 general categories: those with a recognized syndrome, those with sensorineural hearing loss unrelated to any known syndrome, and those with microtia. A great variety of inner ear anomalies was detected, but rarely were these characteristic of a particular clinical entity. The most common finding was the Mondini malformation or one of its variants. Isolated dysplasia of the internal auditory canal or the vestibular aqueduct may be responsible for sensorineural hearing loss in some patients. Patients with microtia may also have severe inner ear abnormalities despite the fact that the outer and inner ears develop embryologically from completely separate systems.

  10. Eldercare at Home: Hearing Problems

    Science.gov (United States)

    ... members and friends to comment on how much communication has improved when your mother is wearing the hearing aid. If your mother is concerned about the appearance of a hearing aid, tell her that most women can style their hair to cover the hearing aids. Problem " ...

  11. A self-cleaning underwater superoleophobic mesh for oil-water separation

    KAUST Repository

    Zhang, Lianbin

    2013-07-31

    Oil-water separation has recently become a global challenging task because of the frequent occurrence of oil spill accidents due to the offshore oil production and transportation, and there is an increasing demand for the development of effective and inexpensive approaches for the cleaning-up of the oily pollution in water system. In this study, a self-cleaning underwater superoleophobic mesh that can be used for oil-water separation is prepared by the layer-by-layer (LbL) assembly of sodium silicate and TiO2 nanoparticles on the stainless steel mesh. The integration of the self-cleaning property into the all-inorganic separation mesh by using TiO2 enables the convenient removal of the contaminants by ultraviolet (UV) illumination, and allows for the facile recovery of the separation ability of the contaminated mesh, making it promising for practial oil-water separation applications.

  12. Time Optimal Hybrid Sliding Mode-PI Control for an Autonomous Underwater Robot

    Directory of Open Access Journals (Sweden)

    Theerayuth Chatchanayuenyong

    2008-03-01

    Full Text Available This paper presents an underwater robot control system using combination principle among sliding mode control (SMC, Pontryagin maximum principle and linear PI control. The SMC switches according to the Pontryagin's time optimal control principle, in which the solution is obtained by using neural network approach to yield a time optimal response at its reaching phase. PI control is used in place of the SMC at the switching phase to avoid high undesired control activity. Performance of the proposed controller is compared with various classical SMCs and conventional linear control systems. Such comparisons ensure the implementation success and prove it as a real time-optimal controller. The results show the controller's good abilities to deal with plant nonlinearity and parameter uncertainties. The controller yields a time optimal control response without high control chattering.

  13. Time Optimal Hybrid Sliding Mode-PI Control for an Autonomous Underwater Robot

    Directory of Open Access Journals (Sweden)

    Theerayuth Chatchanayuenyong

    2008-11-01

    Full Text Available This paper presents an underwater robot control system using combination principle among sliding mode control (SMC, Pontryagin maximum principle and linear PI control. The SMC switches according to the Pontryagin's time optimal control principle, in which the solution is obtained by using neural network approach to yield a time optimal response at its reaching phase. PI control is used in place of the SMC at the switching phase to avoid high undesired control activity. Performance of the proposed controller is compared with various classical SMCs and conventional linear control systems. Such comparisons ensure the implementation success and prove it as a real time-optimal controller. The results show the controller's good abilities to deal with plant nonlinearity and parameter uncertainties. The controller yields a time optimal control response without high control chattering.

  14. A TDoA Localization Scheme for Underwater Sensor Networks with Use of Multilinear Chirp Signals

    Directory of Open Access Journals (Sweden)

    En Cheng

    2016-01-01

    Full Text Available Due to the multipath, Doppler, and other effects, the node location signals have high probability of access collision in the underwater acoustic sensor networks (UW-ASNs, and therefore, it causes the signal lost and the access block; therefore, it constrains the networks performance. In this paper, we take the multilinear chirp (MLC signals as the location signal to improve the anticollision ability. In order to increase the detection efficiency of MLC, we propose a fast efficient detection method called mixing change rate-fractional Fourier transform (MCR-FrFT. This method transforms the combined rates of MLC into symmetry triangle rates and then separates the multiuser signals based on the transformed rates by using FrFT. Theoretical derivation and simulation results show that the proposed method can detect the locations signals, estimate the time difference of arrival (TDoA, reduce the multiple access interference, and improve the location performance.

  15. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun

    2016-09-20

    This paper presents a self-powered underwater acoustic transmitter using a piezoelectric beam to harvest the mechanical energy from fish swimming. This transmitter does not require a battery and is demonstrated in live fish. It transmits an acoustic waveform as the implanted fish swims. It enables long-term monitoring of aquatic animals.

  16. Different survival strategies amongst plants to cope with underwater conditions

    NARCIS (Netherlands)

    Van Veen, Hans; Vashisht, Divya; Voesenek, Laurentius A C J; Sasidharan, Rashmi

    2014-01-01

    Many plants experience flooding at some point during their life cycle. The underwater environment creates a carbon and energy crisis for the plant, for which two successful strategies have been identified, quiescence and escape. During quiescence, growth is actively reduced until the water levels

  17. Optimal BRUVs (baited remote underwater video system) survey ...

    African Journals Online (AJOL)

    Marine protected areas (MPAs) play an important role in coastal conservation, but there is presently no uniformly applied methodology for monitoring the efficacy of coastal fish protection. Whereas underwater visual census and controlled angling surveys have been used, their skilled-labour requirements and environmental ...

  18. Moving in extreme environments: inert gas narcosis and underwater activities.

    Science.gov (United States)

    Clark, James E

    2015-01-01

    Exposure to the underwater environment for pleasure or work poses many challenges on the human body including thermal stress, barotraumas, decompression sickness as well as the acute effects of breathing gases under pressure. With the popularity of recreational self-contained underwater breathing apparatus (SCUBA) diving on the increase and deep inland dive sites becoming more accessible, it is important that we understand the effects of breathing pressurised gas at depth can have on the body. One of the common consequences of hyperbaric gas is the narcotic effect of inert gas. Nitrogen (a major component of air) under pressure can impede mental function and physical performance at depths of as little as 10 m underwater. With increased depth, symptoms can worsen to include confusion, disturbed coordination, lack of concentration, hallucinations and unconsciousness. Narcosis has been shown to contribute directly to up to 6% of deaths in divers and is likely to be indirectly associated with other diving incidents at depth. This article explores inert gas narcosis, the effect on divers' movement and function underwater and the proposed physiological mechanisms. Also discussed are some of the factors that affect the susceptibility of divers to the condition. In conclusion, understanding the cause of this potentially debilitating problem is important to ensure that safe diving practices continue.

  19. Evaluation of Underwater Image Enhancement Algorithms under Different Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Marino Mangeruga

    2018-01-01

    Full Text Available Underwater images usually suffer from poor visibility, lack of contrast and colour casting, mainly due to light absorption and scattering. In literature, there are many algorithms aimed to enhance the quality of underwater images through different approaches. Our purpose was to identify an algorithm that performs well in different environmental conditions. We have selected some algorithms from the state of the art and we have employed them to enhance a dataset of images produced in various underwater sites, representing different environmental and illumination conditions. These enhanced images have been evaluated through some quantitative metrics. By analysing the results of these metrics, we tried to understand which of the selected algorithms performed better than the others. Another purpose of our research was to establish if a quantitative metric was enough to judge the behaviour of an underwater image enhancement algorithm. We aim to demonstrate that, even if the metrics can provide an indicative estimation of image quality, they could lead to inconsistent or erroneous evaluations.

  20. Estimate-Merge-Technique-based algorithms to track an underwater ...

    Indian Academy of Sciences (India)

    D V A N Ravi Kumar

    2017-07-04

    Jul 4, 2017 ... Abstract. Bearing-only passive target tracking is a well-known underwater defence issue dealt in the recent past with the conventional nonlinear estimators like extended Kalman filter (EKF) and unscented Kalman filter. (UKF). It is being treated now-a-days with the derivatives of EKF, UKF and a highly ...

  1. Netcentric underwater warfare; The Remedy for 'Silent Subs'?

    NARCIS (Netherlands)

    Ort, C.M.; Beerens, S.P.; Theije, P.A.M. de

    2004-01-01

    Although in most recent crises around the world it would appear from a superficial glance that there was no imminent underwater threat, a closer look shows differently. In the War on Iraq, for instance, a large allied effort was spent on eliminating the very real mine threat that endangered the

  2. Interaction tools for underwater shock analysis in naval platform design

    NARCIS (Netherlands)

    Aanhold, J.E.; Tuitman, J.T.; Trouwborst, W.; Vaders, J.A.A.

    2016-01-01

    In order to satisfy the need for good quality UNDerwater EXplosion (UNDEX) response estimates of naval platforms, TNO developed two 3D simulation tools: the Simplified Interaction Tool (SIT) and the hydro/structural code 3DCAV. Both tools are an add-on to LS-DYNA. SIT is a module of user routines

  3. Network lifetime-aware data collection in Underwater Sensor ...

    Indian Academy of Sciences (India)

    Development of energy-efficient data collection and routing schemes for Underwater Wireless Sensor Networks (UWSNs) is a challenging issue due to the peculiarities of the underlying physical layer technology. Since the recharging or replacement of sensor nodes is almost impossible after deployment, the critical issue of ...

  4. The effect of floating deck structures on underwater radiated noise

    NARCIS (Netherlands)

    Bosschaart, C.; Jansen, H.W.; Jong, C.A.F. de; Basten, T.

    2017-01-01

    A concept for underwater machinery noise mitigation of future civil and military ships is the application of a common deck structure, supporting multiple machines, which is installed on resilient mounts on the ship's foundation structure. TNO is addressing the availability and testing of tools to be

  5. Underwater sound produced by individual drop impacts and rainfall

    DEFF Research Database (Denmark)

    Pumphrey, Hugh C.; Crum, L. A.; Jensen, Leif Bjørnø

    1989-01-01

    ; the second occurs for some impacts but not others. A range of conditions is described in which a bubble is produced for every drop impact, and it is shown that these conditions are likely to be met by a significant fraction of the raindrops in a typical shower. Underwater sound produced by artificial as well...

  6. Student-Built Underwater Video and Data Capturing Device

    Science.gov (United States)

    Whitt, F.

    2016-12-01

    Students from Stockbridge High School Robotics Team invention is a low cost underwater video and data capturing device. This system is capable of shooting time-lapse photography and/or video for up to 3 days of video at a time. It can be used in remote locations without having to change batteries or adding additional external hard drives for data storage. The video capturing device has a unique base and mounting system which houses a pi drive and a programmable raspberry pi with a camera module. This system is powered by two 12 volt batteries, which makes it easier for users to recharge after use. Our data capturing device has the same unique base and mounting system as the underwater camera. The data capturing device consists of an Arduino and SD card shield that is capable of collecting continuous temperature and pH readings underwater. This data will then be logged onto the SD card for easy access and recording. The low cost underwater video and data capturing device can reach depths up to 100 meters while recording 36 hours of video on 1 terabyte of storage. It also features night vision infrared light capabilities. The cost to build our invention is $500. The goal of this was to provide a device that can easily be accessed by marine biologists, teachers, researchers and citizen scientists to capture photographic and water quality data in marine environments over extended periods of time.

  7. ULTRA: Underwater Localization for Transit and Reconnaissance Autonomy

    Science.gov (United States)

    Huntsberger, Terrance L.

    2013-01-01

    This software addresses the issue of underwater localization of unmanned vehicles and the inherent drift in their onboard sensors. The software gives a 2 to 3 factor of improvement over the state-of-the-art underwater localization algorithms. The software determines the localization (position, heading) of an AUV (autonomous underwater vehicle) in environments where there is no GPS signal. It accomplishes this using only the commanded position, onboard gyros/accelerometers, and the bathymetry of the bottom provided by an onboard sonar system. The software does not rely on an onboard bathymetry dataset, but instead incrementally determines the position of the AUV while mapping the bottom. In order to enable long-distance underwater navigation by AUVs, a localization method called ULTRA uses registration of the bathymetry data products produced by the onboard forward-looking sonar system for hazard avoidance during a transit to derive the motion and pose of the AUV in order to correct the DR (dead reckoning) estimates. The registration algorithm uses iterative point matching (IPM) combined with surface interpolation of the Iterative Closest Point (ICP) algorithm. This method was used previously at JPL for onboard unmanned ground vehicle localization, and has been optimized for efficient computational and memory use.

  8. A highly versatile autonomous underwater vehicle with biomechanical propulsion

    NARCIS (Netherlands)

    Simons, D.G.; Bergers, M.M.C.; Henrion, S.; Hulzenga, J.I.J.; Jutte, R.W.; Pas, W.M.G.; Van Schravendijk, M.; Vercruyssen, T.G.A.; Wilken, A.P.

    2009-01-01

    An autonomous underwater vehicle with a biomechanical propulsion system is a possible answer to the demand for small, silent sensor platforms in many fields. The design of Galatea, a bio-mimetic AUV, involves four aspects: hydrodynamic shape, the propulsion, the motion control systems and payload.

  9. 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

  10. Underwater Wireless Optical Communication System Using Blue LEDs

    Science.gov (United States)

    Lin, Aobo; Tong, Zheng; Song, Yuhang; Kong, Meiwei; Xu, Jing

    2016-02-01

    We demonstrate a self-designed underwater wireless optical communication system using blue LEDs. The performance of the transmitter and receiver was experimentally investigated. Four different square wave signals (10 KHz, 100 KHz, 500 KHz and 1 MHz) were successfully transmitted via a short water channel at the first phase.

  11. BER evaluations for multimode beams in underwater turbulence

    Science.gov (United States)

    Altay Arpali, Serap; Baykal, Yahya; Arpali, Çağlar

    2016-07-01

    In underwater optical communication links, bit error rate (BER) is an important performance criterion. For this purpose, the effects of oceanic turbulence on multimode laser beam incidences are studied and compared in terms of average BER (), which is related to the scintillation index. Based on the log-normal distribution, is analysed for underwater turbulence parameters, including the rate of dissipation of the mean squared temperature, the rate of dissipation of the turbulent kinetic energy, the parameter that determines the relative strength of temperature and salinity in driving index fluctuations, the Kolmogorov microscale length and other link parameters such as link length, wavelength and laser source size. It is shown that use of multimode improves the system performance of optical wireless communication systems operating in an underwater medium. For all the investigated multimode beams, decreasing link length, source size, the relative strength of temperature and salinity in driving the index fluctuations, the rate of dissipation of the mean squared temperature and Kolmogorov microscale length improve the . Moreover, lower values are obtained for the increasing wavelength of operation and the rate of dissipation of the turbulent kinetic energy in underwater turbulence.

  12. Experimental Assessment of Underwater Radiated Sound of Different Ship Types

    NARCIS (Netherlands)

    Jansen, H.W.; Jong, C.A.F. de

    2015-01-01

    The aim of the SONIC project is to develop tools to investigate and mitigate the effects of underwater noise generated by shipping. One way to study the contribution of shipping noise to the background noise in the seas is to produce shipping noise maps. The SONIC project delivers the required

  13. AEKF-SLAM: A New Algorithm for Robotic Underwater Navigation.

    Science.gov (United States)

    Yuan, Xin; Martínez-Ortega, José-Fernán; Fernández, José Antonio Sánchez; Eckert, Martina

    2017-05-21

    In this work, we focus on key topics related to underwater Simultaneous Localization and Mapping (SLAM) applications. Moreover, a detailed review of major studies in the literature and our proposed solutions for addressing the problem are presented. The main goal of this paper is the enhancement of the accuracy and robustness of the SLAM-based navigation problem for underwater robotics with low computational costs. Therefore, we present a new method called AEKF-SLAM that employs an Augmented Extended Kalman Filter (AEKF)-based SLAM algorithm. The AEKF-based SLAM approach stores the robot poses and map landmarks in a single state vector, while estimating the state parameters via a recursive and iterative estimation-update process. Hereby, the prediction and update state (which exist as well in the conventional EKF) are complemented by a newly proposed augmentation stage. Applied to underwater robot navigation, the AEKF-SLAM has been compared with the classic and popular FastSLAM 2.0 algorithm. Concerning the dense loop mapping and line mapping experiments, it shows much better performances in map management with respect to landmark addition and removal, which avoid the long-term accumulation of errors and clutters in the created map. Additionally, the underwater robot achieves more precise and efficient self-localization and a mapping of the surrounding landmarks with much lower processing times. Altogether, the presented AEKF-SLAM method achieves reliably map revisiting, and consistent map upgrading on loop closure.

  14. Synthesis and Development of Gold Polypyrrole Actuator for Underwater Application

    Science.gov (United States)

    Panda, S. K.; Bandopadhya, D.

    2018-02-01

    Electro-active polymer (EAP) such as Polypyrrole has gained much attention in the category of functional materials for fabrication of both active actuator and sensor. Particularly, PPy actuator has shown potential in fluid medium application because of high strain, large bending displacement and work density. This paper focuses on developing a low cost active actuator promising in delivering high performance in underwater environment. The proposed Au-pyrrole actuator is synthesized by adopting the layer-by-layer electrochemical polymerization technique and is fabricated as strip actuator from aqueous solution of Pyrrole and NaDBS in room temperature. In the follow-up, topographical analysis has been carried out using SEM and FESEM instruments showing surface morphology and surface integrity of chemical components of the structure. Several experiments have been conducted under DC input voltage evaluating performance effectiveness such as underwater bending displacement and tip force etc. This is observed that the actuator exhibits quite similar stress profile as of natural muscle, endowed with high modulus makes them effective in working nearly 10,000 cycles underwater environment. In addition, the bending displacement up to 5.4 mm with a low input voltage 1.3 V makes the actuator suitable for underwater micro-robotics applications.

  15. Swimming, swarming and sensing. Bio-inspired underwater robotics

    NARCIS (Netherlands)

    Henrion, S.; Vercruyssen, T.; Müller, U.K.

    2014-01-01

    For operations in complex underwater environments, bio-inspired robots offer manoeuvrability, stealth and autonomy. They integrate propulsion and control systems into one multi-purpose undulatory propeller. By generating large counteracting forces, undulating fins generate a wide range of net

  16. Remote Underwater Characterization System - Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    Willis, W.D.

    1999-01-01

    Characterization and inspection of water-cooled and moderated nuclear reactors and fuel storage pools requires equipment capable of operating underwater. Similarly, the deactivation and decommissioning of older nuclear facilities often requires the facility owner to accurately characterize underwater structures and equipment which may have been sitting idle for years. The Remote Underwater Characterization System (RUCS) is a small, remotely operated submersible vehicle intended to serve multiple purposes in underwater nuclear operations. It is based on the commercially-available Scallop vehicle 1 , but has been modified by the Department of Energys Robotics Technology Development Program to add auto-depth control, and vehicle orientation and depth monitoring at the operator control panel. The RUCS is designed to provide visual and gamma radiation characterization, even in confined or limited access areas. It was demonstrated in August 1998 at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the INEEL Large Scale Demonstration and Deployment Project. During the demonstration it was compared in a ''head-to-head fashion with the baseline characterization technology. This paper summarizes the results of the demonstration and lessons learned; comparing and contrasting both technologies in the areas of cost, visual characterization, radiological characterization, and overall operations

  17. MA-23-6000: underwater bilateral servo master slave manipulator

    International Nuclear Information System (INIS)

    Vertut, Jean

    The different types of manipulators, recent data on their dexterity and the underwater work possible with servo master slave manipulators are reviewed. The general specifications of the manipulator MA 23-6000 designed for the machine ERIC II are given [fr

  18. A network coding based routing protocol for underwater sensor networks.

    Science.gov (United States)

    Wu, Huayang; Chen, Min; Guan, Xin

    2012-01-01

    Due to the particularities of the underwater environment, some negative factors will seriously interfere with data transmission rates, reliability of data communication, communication range, and network throughput and energy consumption of underwater sensor networks (UWSNs). Thus, full consideration of node energy savings, while maintaining a quick, correct and effective data transmission, extending the network life cycle are essential when routing protocols for underwater sensor networks are studied. In this paper, we have proposed a novel routing algorithm for UWSNs. To increase energy consumption efficiency and extend network lifetime, we propose a time-slot based routing algorithm (TSR).We designed a probability balanced mechanism and applied it to TSR. The theory of network coding is introduced to TSBR to meet the requirement of further reducing node energy consumption and extending network lifetime. Hence, time-slot based balanced network coding (TSBNC) comes into being. We evaluated the proposed time-slot based balancing routing algorithm and compared it with other classical underwater routing protocols. The simulation results show that the proposed protocol can reduce the probability of node conflicts, shorten the process of routing construction, balance energy consumption of each node and effectively prolong the network lifetime.

  19. Advanced flooding-based routing protocols for underwater sensor networks

    NARCIS (Netherlands)

    Isufi, E.; Dol, H.; Leus, G.J.T.

    2016-01-01

    Flooding-based protocols are a reliable solution to deliver packets in underwater sensor networks. However, these protocols potentially involve all the nodes in the forwarding process. Thus, the performance and energy efficiency are not optimal. In this work, we propose some advances of a

  20. Network lifetime-aware data collection in Underwater Sensor ...

    Indian Academy of Sciences (India)

    Jalaja Janardanan Kartha

    2017-09-07

    Sep 7, 2017 ... We model the problem as a constrained optimization prob- lem, considering the peculiarities of the underwater environ- ment, resource limitations and application requirements. In particular, we formulate an optimization problem that maxi- mizes the lifetime of the UWSN, subject to node energy con- straints ...