A cheap earphone for small animals with good frequency response in the ultrasonic frequency range

J Neurosci Methods. 1997 Feb;71(2):187-90. doi: 10.1016/s0165-0270(96)00142-2.


A new type of earphone for binaural stimulation in small animals is described. The characteristic features are: (1) small, 8 mm diameter, can be miniaturised further; (2) cheap, uses no expensive condenser microphone capsule, material costs less than 20 dollars; (3) frequency response flat within 6 dB between 10 kHz and 120 kHz, within 10 dB up to 200 kHz; (4) harmonic distortions at levels of the fundamental frequency below 75 dB SPL is below - 34 dB at worst case (10 kHz); and (5) due to the low price the most stable earphones optimally paired for dichotic stimulation can be selected by screening a number of individual specimen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Audiometry / instrumentation*
  • Audiometry / methods
  • Auditory Threshold / physiology*
  • Chiroptera
  • Hearing / physiology*
  • Ultrasonics*