title: Directional properties of bottlenose dolphin (Tursiops truncatus) clicks, burst-pulse, and whistle sounds.
abstract: The directional properties of bottlenose dolphin clicks, burst-pulse, and whistle signals were measured using a five element array, at horizontal angles of 0°, 45°, 90°, 135°, and 180° relative to a dolphin stationed on an underwater biteplate. Clicks and burst-pulse signals were highly directional with directivity indices of ~11 dB for both signal types. Higher frequencies and higher amplitudes dominated the forward, on-axis sound field. A similar result was found with whistles, where higher frequency harmonics had greater directivity indices than lower frequency harmonics. The results suggest the directional properties of these signals not only provide enhanced information to the sound producer (as in echolocation) but can provide valuable information to conspecific listeners during group coordination and socialization.
authors.affiliation: National Marine Mammal Foundation, 2240 Shelter Island Drive, #204, San Diego, California 92106, USA. brian.branstetter@nmmpfoundation.org
authors.forename: Brian K
authors.initials: BK
authors.lastname: Branstetter
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Moore
authors.forename: James J
authors.initials: JJ
authors.lastname: Finneran
authors.forename: Megan N
authors.initials: MN
authors.lastname: Tormey
authors.forename: Hitomi
authors.initials: H
authors.lastname: Aihara
mesh_terms: D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000502:physiology*; D002138:Calibration; D004455:Echolocation / Q000502:physiology*; D008297:Male; D011312:Pressure; D013018:Sound Spectrography; D014828:Vocalization, Animal / Q000502:physiology*