Cetacean Auditory Psychophysics

Moore, Patrick W.

doi:10.1080/09524622.1997.9753354

Cited by 15 publications

(5 citation statements)

References 46 publications

(43 reference statements)

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“…■ Marine Mammal Auditory Sensitivity (D): A basic measure of auditory sensitivity is the audiogram: a plot of auditory threshold against frequency. Audiograms have been measured for many small cetaceans and pinnipeds that can be kept and trained in captivity, although for most species only a few individuals have been measured (Moore, 1997). The use of electrophysiological techniques to measure evoked auditory potentials allows thresholds to be measured much more quickly, at least for the smaller species and at higher frequencies (Dolphin, 1997).…”

Section: Auditory Damagementioning

confidence: 99%

A Review of the Effects of Seismic Surveys on Marine Mammals

Gordon¹,

Gillespie²,

Potter³

et al. 2003

mar technol soc j

201

134

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This review highlights significant gaps in our knowledge of the effects of seismic air gun noise on marine mammals. Although the characteristics of the seismic signal at different ranges and depths and at higher frequencies are poorly understood, and there are often insufficient data to identify the appropriate acoustic propagation models to apply in particular conditions, these uncertainties are modest compared with those associated with biological factors. Potential biological effects of air gun noise include physical/physiological effects, behavioral disruption, and indirect effects associated with altered prey availability. Physical/physiological effects could include hearing threshold shifts and auditory damage as well as non-auditory disruption, and can be directly caused by sound exposure or the result of behavioral changes in response to sounds, e.g. recent observations suggesting that exposure to loud noise may result in decompression sickness. Direct information on the extent to which seismic pulses could damage hearing are difficult to obtain and as a consequence the impacts on hearing remain poorly known. Behavioral data have been collected for a few species in a limited range of conditions. Responses, including startle and fright, avoidance, and changes in behavior and vocalization patterns, have been observed in baleen whales, odontocetes, and pinnipeds and in some case these have occurred at ranges of tens or hundreds of kilometers. However, behavioral observations are typically variable, some findings are contradictory, and the biological significance of these effects has not been measured. Where feeding, orientation, hazard avoidance, migration or social behavior are altered, it is possible that populations could be adversely affected. There may also be serious long-term consequences due to chronic exposure, and sound could affect marine mammals indirectly by changing the accessibility of their prey species. A precautionary approach to management and regulation must be recommended. While such large degrees of uncertainty remain, this may result in restrictions to operational practices but these could be relaxed if key uncertainties are clarified by appropriate research.

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Section: Auditory Damagementioning

confidence: 99%

A Review of the Effects of Seismic Surveys on Marine Mammals

Gordon¹,

Gillespie²,

Potter³

et al. 2003

mar technol soc j

201

134

View full text Add to dashboard Cite

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“…Different units have been used in hearing tests in air and in water. Air and water differ in impedance; therefore, it has been suggested that land mammal and sea mammal hearing are best compared by converting units of pressure in dB or Pa to intensity as W m −2 (see Moore, 1997). Where appropriate, we have given units in intensity as well as in pressure in pascals (Pa) or dB re: 1 µPa for our measures.…”

Section: Sound Measurement Unitsmentioning

confidence: 99%

Hearing and whistling in the deep sea: depth influences whistle spectra but does not attenuate hearing by white whales (Delphinapterus leucas) (Odontoceti, Cetacea)

Ridgway¹,

Carder²,

Kamolnick

et al. 2001

Journal of Experimental Biology

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SUMMARY Hearing is attenuated in the aerial ear of humans and other land mammals tested in pressure chambers as a result of middle ear impedance changes that result from increased air density. We tested the hypothesis, based on recent middle ear models, that increasing the density of middle ear air at depth might attenuate whale hearing. Two white whales Delphinapterus leucas made dives to a platform at a depth of 5, 100, 200 or 300 m in the Pacific Ocean. During dives to station on the platform for up to 12 min, the whales whistled in response to 500 ms tones projected at random intervals to assess their hearing threshold at each depth. Analysis of response whistle spectra, whistle latency in response to tones and hearing thresholds showed that the increased hydrostatic pressure at depth changed each whale’s whistle response at depth, but did not attenuate hearing overall. The finding that whale hearing is not attenuated at depth suggests that sound is conducted through the head tissues of the whale to the ear without requiring the usual ear drum/ossicular chain amplification of the aerial middle ear. These first ever hearing tests in the open ocean demonstrate that zones of audibility for human-made sounds are just as great throughout the depths to which these whales dive, or at least down to 300 m.

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“…Research in recent years has resulted in significant increases in the understanding of the acoustic characteristics of both echolocation clicks and the subsequent returning echoes (Au, 1993;Au & Hastings, 2008;Au et al, 2008;Houser, Helweg & Moore, 1999;Houser et al, 2005;Moore, 1997;Moore, Dankiewicz, & Houser, 2008), as well as an appreciation of the dolphin ability to eavesdrop on the echoes that result from the clicks produced by another dolphin (Götz, Verfaß, & Schnitzler 2005;Gregg, Dudzinski, & Smith, 2007;Xitco & Roitblat, 1996). However, at the present time we know little about the manner in which information is represented and used by dolphins (Harley, Xitco, & Roitblat, 1995;Popper, Hawkins, & Gisiner, 1997;Roitblat, Helweg, & Harley, 1995;Roitblat, 2004).…”

Section: Discussionmentioning

confidence: 99%