Archives of oto-rhino-laryngology

, Volume 234, Issue 2, pp 213–218

Cochlear mechanisms at low frequencies in the guinea pig

  • R. Franke
  • A. Dancer
Article

Summary

The study of the cochlear microphonic and of the intracochlear sound pressure in guinea pigs shows that the behavior of the cochlea at very low frequencies is controlled by three discrete elements: (a) the compliance of the whole basilar membrane; (b) the acoustic resistance of the helicotrema; (c) the compliance of the round window. The part of each of these elements has been established. The compliance of the whole basilar membrane produces constant amplitudes at frequencies lower than the minimum frequency at which a travelling wave is present (130 Hz). In fact, this constant amplitude range is limited by connection of the two cochlear scalae through the helicotrema resistance. This protecting mechanism produces an attenuation slope for frequencies lower than 80 Hz. The compliance of the round window does not modify the slope of the cochlear microphonic, but it induces a constant sound pressure in scala tympani up to 200 Hz. Decreasing of the sound pressure in the scala vestibuli is, therefore, limited for frequencies less than 30 Hz by this constant value of the sound pressure in scala tympani.

Key words

Cochlea Guinea pig Low-frequencies Cochlear microphonic Intracochlear acoustic pressure Mechanical parameters Cochlear partition Round window Helicotrema 

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References

  1. 1.
    Dallos P (1970) Low-frequency auditory characteristics: species dependance. J Acoust Soc Am 48: 489–499Google Scholar
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    Dancer A, Franke R (1980) Intracochlear sound pressure measurements in guinea pigs. Hearing Res 2: 191–205Google Scholar
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    Mundie JR (1962) The impedance of the ear, a variable quantity. Middle ear function sem. Rep. N 576, US Army Med Res Lab Ft Knox, Kentucky, pp 63–85Google Scholar
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    Zwislocki JJ (1971) Cochlear waves: interaction between theory and experiments. J Acoust Soc Am 55: 578–583Google Scholar

Copyright information

© Springer-Verlag 1982

Authors and Affiliations

  • R. Franke
    • 1
  • A. Dancer
    • 1
  1. 1.French-German Research Institute of Saint-LouisSaint-LouisFrance

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