Hearing mechanisms and noise metrics related to auditory masking in bottlenose dolphins (Tursiops truncatus)
Branstetter, B.K.; Bakhtiari, K.L.; Trickey, J.S.; Finneran, J.J. (2016). Hearing mechanisms and noise metrics related to auditory masking in bottlenose dolphins (Tursiops truncatus), in: Popper, A.N. et al. The effects of noise on aquatic life II. Advances in Experimental Medicine and Biology, 875: pp. 109-116. http://dx.doi.org/10.1007/978-1-4939-2981-8_13
In: Popper, A.N.; Hawkins, A. (Ed.) (2016). The effects of noise on aquatic life II. Advances in Experimental Medicine and Biology, 875. Springer Science+Business Media, Inc: New York. ISBN 978-1-4939-2980-1. xxx, 1292 pp., meer
In: Advances in Experimental Medicine and Biology. Springer: Berlin. ISSN 0065-2598; e-ISSN 2214-8019, meer
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Detection
Tursiops truncatus (Montagu, 1821) [WoRMS]
Marien/Kust |
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| Auteurs | | Top |
- Branstetter, B.K.
- Bakhtiari, K.L.
- Trickey, J.S.
- Finneran, J.J.
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| Abstract |
Odontocete cetaceans are acoustic specialists that depend on sound to hunt, forage, navigate, detect predators, and communicate. Auditory masking from natural and anthropogenic sound sources may adversely affect these fitness-related capabilities. The ability to detect a tone in a broad range of natural, anthropogenic, and synthesized noise was tested with bottlenose dolphins using a psychophysical, band-widening procedure. Diverging masking patterns were found for noise-bandwidths greater than the width of an auditory filter. Despite different noise types having equal-pressure spectral-density levels (95 dB re 1 mu Pa-2/Hz), masked detection threshold differences were as large as 22 dB. Consecutive experiments indicated that noise types with increased levels of amplitude modulation resulted in comodulation masking release due to within-channel and across-channel auditory mechanisms. The degree to which noise types were comodulated (comodulation index) was assessed by calculating the magnitude-squared coherence between the temporal envelope from an auditory filter centered on the signal and temporal envelopes from flanking filters. Statistical models indicate that masked thresholds in a variety of noise types, at a variety of levels, can be explained with metrics related to the comodulation index in addition to the pressure spectral-density level of noise. This study suggests that predicting auditory masking from ocean noise sources depends on both spectral and temporal properties of the noise. |
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