Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Asymmetry and dynamics of a narrow sonar beam in an echolocating harbor porpoise

There are no MPG-Authors in the publication available
External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Koblitz, J. C., Wahlberg, M., Stilz, P., Madsen, P. T., Beedholm, K., & Schnitzler, H. U. (2012). Asymmetry and dynamics of a narrow sonar beam in an echolocating harbor porpoise. The Journal of the Acoustical Society of America, 131(3), 2315-2324. doi:10.1121/1.3683254.

Cite as: https://hdl.handle.net/21.11116/0000-0005-A4D0-6
A key component in the operation of a biosonar system is the radiation of sound energy from the sound producing head structures of toothed whales and microbats. The current view involves a fixed transmission aperture by which the beam width can only change via changes in the frequency of radiated clicks. To test that for a porpoise, echolocation clicks were recorded with high angular resolution using a 16 hydrophone array. The beam is narrower than previously reported (DI = 24 dB) and slightly dorso-ventrally compressed (horizontal -3 dB beam width: 13 degrees, vertical -3 dB beam width: 11 degrees). The narrow beam indicates that all smaller toothed whales investigated so far have surprisingly similar beam widths across taxa and habitats. Obtaining high directionality may thus be at least in part an evolutionary factor that led to high centroid frequencies in a group of smaller toothed whales emitting narrow band high frequency clicks. Despite the production of stereotyped narrow band high frequency clicks, changes in the directionality by a few degrees were observed, showing that porpoises can obtain changes in sound radiation. (C) 2012 Acoustical Society of America. [DOI: 10.1121/1.3683254]