Audiogram of a striped dolphin (Stenella coeruleoalba)

J Acoust Soc Am. 2003 Feb;113(2):1130-7. doi: 10.1121/1.1532310.

Abstract

The underwater hearing sensitivity of a striped dolphin was measured in a pool using standard psycho-acoustic techniques. The go/no-go response paradigm and up-down staircase psychometric method were used. Auditory sensitivity was measured by using 12 narrow-band frequency-modulated signals having center frequencies between 0.5 and 160 kHz. The 50% detection threshold was determined for each frequency. The resulting audiogram for this animal was U-shaped, with hearing capabilities from 0.5 to 160 kHz (8 1/3 oct). Maximum sensitivity (42 dB re 1 microPa) occurred at 64 kHz. The range of most sensitive hearing (defined as the frequency range with sensitivities within 10 dB of maximum sensitivity) was from 29 to 123 kHz (approximately 2 oct). The animal's hearing became less sensitive below 32 kHz and above 120 kHz. Sensitivity decreased by about 8 dB per octave below 1 kHz and fell sharply at a rate of about 390 dB per octave above 140 kHz.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Auditory Threshold / physiology
  • Dolphins / physiology*
  • Female
  • Fourier Analysis
  • Pitch Discrimination / physiology*
  • Signal Processing, Computer-Assisted
  • Sound Spectrography