Killer whale (Orcinus orca) hearing: auditory brainstem response and behavioral audiograms

J Acoust Soc Am. 1999 Aug;106(2):1134-41. doi: 10.1121/1.427121.


Killer whale (Orcinus orca) audiograms were measured using behavioral responses and auditory evoked potentials (AEPs) from two trained adult females. The mean auditory brainstem response (ABR) audiogram to tones between 1 and 100 kHz was 12 dB (re 1 mu Pa) less sensitive than behavioral audiograms from the same individuals (+/- 8 dB). The ABR and behavioral audiogram curves had shapes that were generally consistent and had the best threshold agreement (5 dB) in the most sensitive range 18-42 kHz, and the least (22 dB) at higher frequencies 60-100 kHz. The most sensitive frequency in the mean Orcinus audiogram was 20 kHz (36 dB), a frequency lower than many other odontocetes, but one that matches peak spectral energy reported for wild killer whale echolocation clicks. A previously reported audiogram of a male Orcinus had greatest sensitivity in this range (15 kHz, approximately 35 dB). Both whales reliably responded to 100-kHz tones (95 dB), and one whale to a 120-kHz tone, a variation from an earlier reported high-frequency limit of 32 kHz for a male Orcinus. Despite smaller amplitude ABRs than smaller delphinids, the results demonstrated that ABR audiometry can provide a useful suprathreshold estimate of hearing range in toothed whales.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Audiometry / methods*
  • Auditory Threshold / physiology
  • Behavior, Animal / physiology*
  • Dolphins / physiology*
  • Evoked Potentials, Auditory, Brain Stem / physiology*
  • Female
  • Hearing / physiology*