| Receiving beam patterns in the horizontal plane of a harbor porpoise (Phocoena phocoena). | |
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MedLine Citation:
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PMID: 16158671 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Receiving beam patterns of a harbor porpoise were measured in the horizontal plane, using narrow-band frequency modulated signals with center frequencies of 16, 64, and 100 kHz. Total signal duration was 1000 ms, including a 200 ms rise time and 300 ms fall time. The harbor porpoise was trained to participate in a psychophysical test and stationed itself horizontally in a specific direction in the center of a 16-m-diameter circle consisting of 16 equally-spaced underwater transducers. The animal's head and the transducers were in the same horizontal plane, 1.5 m below the water surface. The go/no-go response paradigm was used; the animal left the listening station when it heard a sound signal. The method of constants was applied. For each transducer the 50% detection threshold amplitude was determined in 16 trials per amplitude, for each of the three frequencies. The beam patterns were not symmetrical with respect to the midline of the animal's body, but had a deflection of 3-7 degrees to the right. The receiving beam pattern narrowed with increasing frequency. Assuming that the pattern is rotation-symmetrical according to an average of the horizontal beam pattern halves, the receiving directivity indices are 4.3 at 16 kHz, 6.0 at 64 kHz, and 11.7 dB at 100 kHz. The receiving directivity indices of the porpoise were lower than those measured for bottlenose dolphins. This means that harbor porpoises have wider receiving beam patterns than bottlenose dolphins for the same frequencies. Directivity of hearing improves the signal-to-noise ratio and thus is a tool for a better detection of certain signals in a given ambient noise condition. |
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Authors:
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Ronald A Kastelein; Mirjam Janssen; Willem C Verboom; Dick de Haan |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The Journal of the Acoustical Society of America Volume: 118 ISSN: 0001-4966 ISO Abbreviation: J. Acoust. Soc. Am. Publication Date: 2005 Aug |
Date Detail:
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Created Date: 2005-09-14 Completed Date: 2006-02-07 Revised Date: 2006-12-27 |
Medline Journal Info:
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Nlm Unique ID: 7503051 Medline TA: J Acoust Soc Am Country: United States |
Other Details:
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Languages: eng Pagination: 1172-9 Citation Subset: IM |
Affiliation:
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Sea Mammal Research Company (SEAMARCO), Julianalaan 46, 3843 CC Harderwijk, The Netherlands. researchteam@zonnet.nl |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Acoustic Stimulation
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instrumentation Animals Conditioning (Psychology) Echolocation / physiology* Male Phocoena / physiology* Pitch Perception / physiology* Psychoacoustics |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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