Accession Number : AD0643381

Title :   AUDITORY THRESHOLDS OF THE BOTTLENOSED PORPOISE (TURSIOPS TRUNCATUS, MONTAGU).

Descriptive Note : Research rept.,

Corporate Author : NAVAL ORDNANCE TEST STATION CHINA LAKE CALIF

Personal Author(s) : Johnson,C. Scott

Report Date : NOV 1966

Pagination or Media Count : 37

Abstract : Standard operant conditioning techniques were used to train a bottlenosed porpoise to respond to pure tone signals by pushing a lever-operated switch. An audiogram was obtained over the frequency range from 75 hertz to 150 kHz. The lowest thresholds (greatest hearing sensitivity) occurred in the frequencies near 50 kHz at a level of about -55 decibels (re 1 microbar). The effective upper limit of hearing for the experimental animal was determined to be 150 kHz. There was no indication of sensitivity to near-field displacements such as those observed in fish. (Author)

Descriptors :   (*CETACEA, HEARING), AUDITORY ACUITY, THRESHOLDS(PHYSIOLOGY), SENSITIVITY, TRAINING

Subject Categories : Anatomy and Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE