title: Auditory temporal resolution of a wild white-beaked dolphin (Lagenorhynchus albirostris).
abstract: Adequate temporal resolution is required across taxa to properly utilize amplitude modulated acoustic signals. Among mammals, odontocete marine mammals are considered to have relatively high temporal resolution, which is a selective advantage when processing fast traveling underwater sound. However, multiple methods used to estimate auditory temporal resolution have left comparisons among odontocetes and other mammals somewhat vague. Here we present the estimated auditory temporal resolution of an adult male white-beaked dolphin, (Lagenorhynchus albirostris), using auditory evoked potentials and click stimuli. Ours is the first of such studies performed on a wild dolphin in a capture-and-release scenario. The white-beaked dolphin followed rhythmic clicks up to a rate of approximately 1,125-1,250 Hz, after which the modulation rate transfer function (MRTF) cut-off steeply. However, 10% of the maximum response was still found at 1,450 Hz indicating high temporal resolution. The MRTF was similar in shape and bandwidth to that of other odontocetes. The estimated maximal temporal resolution of white-beaked dolphins and other odontocetes was approximately twice that of pinnipeds and manatees, and more than ten-times faster than humans and gerbils. The exceptionally high temporal resolution abilities of odontocetes are likely due primarily to echolocation capabilities that require rapid processing of acoustic cues.
authors.affiliation: Department of Zoology and Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1106, Kailua, HI 96734, USA. mooneyt@hawaii.edu
authors.forename: T Aran
authors.initials: TA
authors.lastname: Mooney
authors.forename: Paul E
authors.initials: PE
authors.lastname: Nachtigall
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Taylor
authors.forename: Marianne H
authors.initials: MH
authors.lastname: Rasmussen
authors.forename: Lee A
authors.initials: LA
authors.lastname: Miller
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology*; D010872:Caniformia / Q000502:physiology; D004289:Dolphins / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology; D005849:Gerbillinae / Q000502:physiology; D006801:Humans; D008297:Male; D009622:Noise; D020455:Trichechus / Q000502:physiology