Print Email Facebook Twitter The hearing threshold of a harbor porpoise (Phocoena phocoena) for impulsive sounds (L) Title The hearing threshold of a harbor porpoise (Phocoena phocoena) for impulsive sounds (L) Author Kastelein, R.A. Gransier, R. Hoek, L. de Jong, C.A.F. Publication year 2012 Abstract The distance at which harbor porpoises can hear underwater detonation sounds is unknown, but depends, among other factors, on the hearing threshold of the species for impulsive sounds. Therefore, the underwater hearing threshold of a young harbor porpoise for an impulsive sound, designed to mimic a detonation pulse, was quantified by using a psychophysical technique. The synthetic exponential pulse with a 5 ms time constant was produced and transmitted by an underwater projector in a pool. The resulting underwater sound, though modified by the response of the projection system and by the pool, exhibited the characteristic features of detonation sounds: A zero to peak sound pressure level of at least 30 dB (re 1 s-1) higher than the sound exposure level, and a short duration (34 ms). The animal's 50 detection threshold for this impulsive sound occurred at a received unweighted broadband sound exposure level of 60 dB re 1 μPa2s. It is shown that the porpoise's audiogram for short-duration tonal signals [Kastelein, J. Acoust. Soc. Am. 128, 3211-3222 (2010)] can be used to estimate its hearing threshold for impulsive sounds. © 2012 Acoustical Society of America. Subject Physics & ElectronicsAS - Acoustics & SonarTS - Technical SciencesDefence ResearchDefence, Safety and SecurityHarbor porpoisesSea MammalsUnderwater detonationsHearing thresholdSound pulsesBiological effects To reference this document use: http://resolver.tudelft.nl/uuid:bd50ec08-bfbe-4ac4-953f-8d19646ce4d5 DOI https://doi.org/10.1121/1.4733552 TNO identifier 463745 Source Journal of the Acoustical Society of America, 132 (2), 607-610 Bibliographical note Letters to the Editor Document type article Files To receive the publication files, please send an e-mail request to TNO Library.