scholarly journals Sonar-induced temporary hearing loss in dolphins

2009 ◽  
Vol 5 (4) ◽  
pp. 565-567 ◽  
Author(s):  
T. Aran Mooney ◽  
Paul E. Nachtigall ◽  
Stephanie Vlachos

There is increasing concern that human-produced ocean noise is adversely affecting marine mammals, as several recent cetacean mass strandings may have been caused by animals' interactions with naval ‘mid-frequency’ sonar. However, it has yet to be empirically demonstrated how sonar could induce these strandings or cause physiological effects. In controlled experimental studies, we show that mid-frequency sonar can induce temporary hearing loss in a bottlenose dolphin ( Tursiops truncatus ). Mild-behavioural alterations were also associated with the exposures. The auditory effects were induced only by repeated exposures to intense sonar pings with total sound exposure levels of 214 dB re: 1 μPa 2  s. Data support an increasing energy model to predict temporary noise-induced hearing loss and indicate that odontocete noise exposure effects bear trends similar to terrestrial mammals. Thus, sonar can induce physiological and behavioural effects in at least one species of odontocete; however, exposures must be of prolonged, high sound exposures levels to generate these effects.

Author(s):  
A. Delgado ◽  
F. Carvalho ◽  
R. B. Melo

Musical instruments and singers' voices can reach high sound pressure values representing a risk to hearing health, which is of particular relevance for music teachers. Therefore, the potential risk of hearing damage among music teachers in a university school of music was assessed. Twenty teachers completed all phases of the study. Sound pressure levels were measured with a sound meter and daily noise exposure levels were computed and compared with legal reference values in force. Three types of hearing exams were administered to all teachers by health technicians. Most teachers (75%) were subjected to daily noise exposure levels below 80 dB(A). Teaching to play brass instruments appears to be the most risky activity. Only three subjects were diagnosed with noise-induced hearing loss, which cannot be exclusively ascribed to occupational activities because they are involved in extracurricular activities. Increased sample size and the use of noise dosimetry would have improved the study conclusions.


2019 ◽  
Vol 76 (Suppl 1) ◽  
pp. A5.3-A6
Author(s):  
Zara Ann Stokholm ◽  
Inge Brosbøl Iversen ◽  
Henrik Kolstad

Current legislation and threshold limits for occupational noise exposure may not sufficiently account for higher vulnerability of the foetus. We conducted a systematic literature review and identified 20 relevant studies of prenatal noise exposure levels and health. Maternal tissues attenuate industrial noise by about 30 dB. The foetus responds the earliest to noise exposure from the 19th week of gestational age. There is some evidence of an increased risk of hearing loss at prenatal noise levels≥85 dBA (8 hour average) and little evidence at lower levels. Increased risks for preterm birth, small-for-gestational-age and congenital malformations are seen as single study findings at levels≥90 dBA. There is little evidence for how noise exposure may increase the risk of extra-auditive effects in the foetus. Methodological shortcomings and the scarce number of studies limit the conclusions that can be drawn. Still, we recommend pregnant women avoid working at noise levels≥85 dBA.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mads Peter Heide-Jørgensen ◽  
Susanna B. Blackwell ◽  
Outi M. Tervo ◽  
Adeline L. Samson ◽  
Eva Garde ◽  
...  

One of the last pristine marine soundscapes, the Arctic, is exposed to increasing anthropogenic activities due to climate-induced decrease in sea ice coverage. In this study, we combined movement and behavioral data from animal-borne tags in a controlled sound exposure study to describe the reactions of narwhals, Monodon monoceros, to airgun pulses and ship noise. Sixteen narwhals were live captured and instrumented with satellite tags and Acousonde acoustic-behavioral recorders, and 11 of them were exposed to airgun pulses and vessel sounds. The sound exposure levels (SELs) of pulses from a small airgun (3.4 L) used in 2017 and a larger one (17.0 L) used in 2018 were measured using drifting recorders. The experiment was divided into trials with airgun and ship-noise exposure, intertrials with only ship-noise, and pre- and postexposure periods. Both trials and intertrials lasted ∼4 h on average per individual. Depending on the location of the whales, the number of separate exposures ranged between one and eight trials or intertrials. Received pulse SELs dropped below 130 dB re 1 μPa2 s by 2.5 km for the small airgun and 4–9 km for the larger airgun, and background noise levels were reached at distances of ∼3 and 8–10.5 km, respectively, for the small and big airguns. Avoidance reactions of the whales could be detected at distances >5 km in 2017 and >11 km in 2018 when in line of sight of the seismic vessel. Meanwhile, a ∼30% increase in horizontal travel speed could be detected up to 2 h before the seismic vessel was in line of sight. Applying line of sight as the criterion for exposure thus excludes some potential pre-response effects, and our estimates of effects must therefore be considered conservative. The whales reacted by changing their swimming speed and direction at distances between 5 and 24 km depending on topographical surroundings where the exposure occurred. The propensity of the whales to move towards the shore increased with increasing exposure (i.e., shorter distance to vessels) and was highest with the large airgun used in 2018, where the whales moved towards the shore at distances of 10–15 km. No long-term effects of the response study could be detected.


2007 ◽  
Vol 22 (4) ◽  
pp. 160-165 ◽  
Author(s):  
Vanessa L Miller ◽  
Michael Stewart ◽  
Mark Lehman

Twenty-seven student musicians were surveyed regarding musical practice and playing habits, knowledge of hearing conservation practices, use of hearing protective devices (HPD), and the occurrence of tinnitus after exposure to loud music. In addition, noise exposure levels during practice and sporting events (football and basketball games) at which they played were monitored with a dosimeter simultaneously set to measure noise levels using the OSHA (1983) and NIOSH (1998) measurement criteria. Forty-eight percent of the subjects reported practicing or playing their instrument <10 hours a week. Most musicians (74%) reported having been taught about the effects of noise on hearing and health; however, less than a third used ear protection while playing their instruments, and those who did used it inconsistently. Sixty-three percent of subjects reported experiencing tinnitus after exposure to loud music. Finally, 8-hour time-weighted averages (TWA) and daily noise doses were significantly higher using the NIOSH measurement criteria than the OSHA measurement criteria. Both measurement criteria yielded values that exceeded a 100% daily noise dose for all subjects. Overall, these results indicate that university student directors and musicians appear to be at high risk for permanent noise-induced hearing loss secondary to excessive exposure to loud music. These results support the need for on-going hearing conservation programs to educate student musicians and student directors about the dangers of excessive exposure to loud music.


2020 ◽  
Vol 35 (4) ◽  
pp. 227-232
Author(s):  
Haley Busenbarrick ◽  
Kathleen L. Davenport

Enduring exposure to high sound pressure levels (SPLs) can lead to noise-induced hearing loss (NIHL). In the performing arts population, NIHL has been studied primarily in the context of sound exposure experienced by musicians and less so by dancers. This research aimed to identify sound exposure that dancers may experience in some dance classes. Decibel levels were recorded in 12 dance classes (6 ballet, 4 modern, and 1 soft and 1 hard shoe Irish dance) at 8 different studios using the NIOSH SLM app on an iOS smartphone with external microphone. A minimum of five recordings of each class was measured, each collected on a different day, yielding a total of 114 measurements. Results showed that 20.2% of all recordings exceeded the recommended NIOSH sound exposure limits of both 100% projected daily dose and 85 LAeq. Analysis between styles of dance demonstrated significantly lower LAeq (p≤0.05) in soft shoe Irish dance compared to ballet (p=0.023), modern (p=0.035), and Irish hard shoe dance (p=0.009). Irish soft shoe dance demonstrated minimal to no risk of high sound exposure. Conversely, 53.25% of ballet, 90.9% of Irish hard shoe dance, and 68.24% of modern recordings exhibited minimal to moderate risk of high sound exposure. Furthermore, we found wide ranges of projected daily noise doses within classes taught by the same teacher. It is recommended that multiple recordings of dance environments be obtained, as a single sound recording may not accurately represent potential exposure. These findings indicate that dancers of Irish hard shoe, modern, and ballet may benefit from noise intervention such as audiometric testing, noise controls, and hearing protection.


2003 ◽  
Vol 37 (4) ◽  
pp. 6-15 ◽  
Author(s):  
Douglas Wartzok ◽  
Arthur N. Popper ◽  
Jonathan Gordon ◽  
Jennifer Merrill

The issues surrounding marine mammals and noise cannot be managed effectively without an understanding of the effects of that noise on individual mammals and their populations. In the spring of 2003 the National Research Council released Ocean Noise and Marine Mammals, a report that reviewed sources of ocean noise (natural and anthropogenic), the effects of noise on marine mammals, patterns and long-term trends in ocean noise, and included recommendations intended to improve understanding of the sources and impacts of anthropogenic marine noise. This paper provides a brief summary of observed effects of ocean noise on marine mammals and the factors that can change the response of the animal to the noise exposure. It introduces the reader to short- and long-term behavior changes that have been observed in marine mammals in response to ocean noise, and discusses future directions for marine mammal research.


2019 ◽  
Vol 31 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Graeme Shannon ◽  
Megan F McKenna ◽  
Grete E Wilson-Henjum ◽  
Lisa M Angeloni ◽  
Kevin R Crooks ◽  
...  

Abstract Increasing anthropogenic noise is having a global impact on wildlife, particularly due to the masking of crucial acoustical communication. However, there have been few studies examining the impacts of noise exposure on communication in free-ranging terrestrial mammals. We studied alarm calls of black-tailed prairie dogs (Cynomys ludovicianus) across an urban gradient to explore vocal adjustment relative to different levels of noise exposure. There was no change in the frequency 5%, peak frequency, or duration of the alarm calls across the noise gradient. However, the minimum frequency—a commonly used, yet potentially compromised metric—did indeed show a positive relationship with noise exposure. We suspect this is a result of masking of observable call properties by noise, rather than behavioral adjustment. In addition, the proximity of conspecifics and the distance to the perceived threat (observer) did affect the frequency 5% of alarm calls. These results reveal that prairie dogs do not appear to be adjusting their alarm calls in noisy environments but likely do in relation to their social context and the proximity of a predatory threat. Anthropogenic noise can elicit a range of behavioral and physiological responses across taxa, but elucidating the specific mechanisms driving these responses can be challenging, particularly as these are not necessarily mutually exclusive. Our research sheds light on how prairie dogs appear to respond to noise as a source of increased risk, rather than as a distraction or through acoustical masking as shown in other commonly studied species (e.g., fish, songbirds, marine mammals).


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qixuan Wang ◽  
Xueling Wang ◽  
Lu Yang ◽  
Kun Han ◽  
Zhiwu Huang ◽  
...  

Abstract Background Significant sex differences exist in hearing physiology, while few human studies have investigated sex differences in noise-induced hearing loss (NIHL), and the sex bias in previous studies resulted in inadequate female data. The study aims to investigate sex differences in the characteristics of NIHL to provide insight into sex-specific risk factors, prevention strategies and treatment for NIHL. Methods This cross-sectional study included 2280 industrial noise-exposed shipyard workers (1140 males and 1140 females matched for age, job and employment length) in China. Individual noise exposure levels were measured to calculate the cumulative noise exposure (CNE), and an audiometric test was performed by an experienced technician in a soundproof booth. Sex differences in and influencing factors of low-frequency (LFHL) and high-frequency hearing loss (HFHL) were analyzed using logistic regression models stratified by age and CNE. Results At comparable noise exposure levels and ages, the prevalence of HFHL was significantly higher in males (34.4%) than in females (13.8%), and males had a higher prevalence of HFHL (OR = 4.19, 95% CI 3.18 to 5.52) after adjusting for age, CNE, and other covariates. Sex differences were constant and highly remarkable among subjects aged 30 to 40 years and those with a CNE of 80 to 95 dB(A). Alcohol consumption might be a risk factor for HFHL in females (OR = 3.12, 95% CI 1.10 to 8.89). Conclusions This study indicates significant sex differences in NIHL. Males are at higher risk of HFHL than females despite equivalent noise exposure and age. The risk factors for NIHL might be different in males and females.


2009 ◽  
Vol 24 (2) ◽  
pp. 63-70
Author(s):  
Jennifer Stewart Walter

The purpose of this study was 1) to examine the sound exposure of wind band members in a university setting during a week of typical rehearsals and 2) to assess whether that exposure changes depending on subjects' location within the rehearsal space. Because excessive sound exposure has a cumulative effect on the ear that can eventually lead to noise-induced hearing loss, it is important to determine whether university musicians are at risk. A 100% dose of sound is the maximum daily exposure recommended by the National Institute of Occupational Safety and Health (NIOSH) for preventing noise-induced hearing loss. Twenty-four of 46 subjects (52%) experienced one or more rehearsals with sound levels high enough to produce >100% doses, and 17 subjects experienced a mean daily dose of sound in excess of 100% as compared to the NIOSH standards. Implications and suggestions for further research are discussed.


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