Underwater Audiogram of a False Killer Whale (Pseudorca crassidens)

• Main Authors: Thomas, Jeanette, Chun, Norman, Au, Whitlow, Pugh, Kiana
• Other Authors: NAVAL OCEAN SYSTEMS CENTER SAN DIEGO CA
• Format: Text
• Language: English
• Published: 1988
• Subjects: Biology; Biological Oceanography; *WHALES; PORPOISES; REPRINTS; PEAK VALUES; SENSITIVITY; PULSES; RESPONSE; MARINE BIOLOGY; PSYCHOMETRICS; HARBORS; HAWAII; HEARING; ECHO RANGING; UNDERWATER; AMAZON RIVER; MARINE BIOLOGICAL NOISE; AUDITORY SIGNALS; AUDIO TONES; AUDIOMETRY; DOLPHINS(MAMMALS); TEST AND EVALUATION; FREQUENCY; *FALSE KILLER WHALES; *AUDIOGRAMS; *PSEUDORCA CRASSIDENS; PE62435N; WUDN688674; Beluga; Beluga*; Delphinapterus leucas; Killer Whale
• Online Access: http://www.dtic.mil/docs/citations/ADA208080; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA208080

Underwater audiograms are available for only a few odontocete species. A false killer whale (Pseudorca crassidens) was trained at Sea Life Park in Oahu, Hawaii for an underwater hearing test using a go/no-go response paradigm. Over 6-month period, auditory thresholds from 2-115 kHz were measured using an up/down staircase psychometric technique. The resulting audiogram showed hearing sensitivities below 64 kHz similar to those of belugas (Delphinapterus leucas) and Atlantic bottlenosed dolphins (Tursiops truncatus). Above 64 KHz, this Pseudorca had a rapid decrease in sensitivity of about 150 dB per octave. A similar decrease in sensitivity occurs at 32 kHz in the killer whale, at 50 kHz in the Amazon River dolphin, at 120 kHz in the beluga, at 140 khz in the bottlenosed dolphin, and at 140 kHz in the harbor porpoise. The most sensitive range of hearing was from 16-64 kHz (a range 10 dB from the maximum sensitivity). This range corresponds with the peak frequency of echolocation pulses recorded from captive Pseudorca. Keywords: Reprints, Marine biology. Pub. in Jnl. of the Acoustical Society of America, v84 n3 p936-940 Sep 1988