Advertisement

Can basilar membrane tuning be inferred from distortion measurement?

  • A. M. Brown
  • S. A. Gaskill
Part of the Lecture Notes in Biomathematics book series (LNBM, volume 87)

Abstract

As the frequency of two tones progressively converge, an increasing number of distortion sidebands of the family (n+1)f1-nf2 (where n is a positive integer) can be detected in cochlear electrical and mechanical responses. If the distortion is measured in the ear canal sound pressure when the stimulus levels are low, each distortion component follows a simple pattern of a rise to a maximum in magnitUde, followed by a decline, often to the noise floor, as the fl and f2 frequencies approximate (Wilson, 1980; Brown & Kemp, 1985; Harriset al.,1988). Distortion has its origin at the stimulus frequency place for the higher frequency stimulus (f2) in the cochlea (Hall, 1980; Kim et al.,1980), so it is somewhat surprising that distortion level decreases as its own frequency approaches that of 1’2. The aim of this work was to see whether the distortion-generating mechanism itself is being suppressed as the stimuli are approximated in frequency or whether the distortion is being subjected to some secondary filtering.

Keywords

Stimulus Level Tectorial Membrane Distortion Level Distortion Component High Frequency Stimulus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Brown, A.M. (1987) Acoustic distortion from rodent ears: a comparison of responses from rats, guinea pigs and gerbils. Hear.Res. 31, 25 - 39.CrossRefGoogle Scholar
  2. Brown, A.M. & Oaskill, S.A. (1990) Measurement of acoustic distortion reveals underlying similarities between human and rodent mechanical responses. J.Acoust.Soc.Am., 88 (July)Google Scholar
  3. Brown, A.M. & Kemp, D.T. (1985) Intermodulation distortion in the cochlea: Could basal vibration be the major cause of round window CM distortion? Hear.Res., 19, 191 - 198.CrossRefGoogle Scholar
  4. Cody, A.R. & Johnstone, B.M. (1981) Acoustic trauma: Single neuron basis for the ’HalfOctave’ shift. J.Acoust.Soc.Am., 70, 707 - 711.ADSCrossRefGoogle Scholar
  5. Gaskill, S.A. & Brown, A.M. (1990) The behaviour of the acoustic distortion product, 2fl-f2, from the human ear and its relation to auditory sensitivity. J.Acoust.Soc,Am., 88 (July)Google Scholar
  6. Harris, F.P., Lonsbury-Martin, B.L., Stagner, B.B., Coats, A.C. & Martin, O.K. (1989) Acoustic distortion products in humans: Systematic changes in amplitude as a function of f2/fl ratio. J.Acoust.Soc.Am.85,220·229.Google Scholar
  7. Hall, J.L. (1980) Cochlear models; evidence in suport of mechanical nonlinearity and a second fIlter. Hear.Res. 2, 455 - 464.CrossRefGoogle Scholar
  8. Kim, D.,.,Molnar, C.E. & Matthews, J.W. (1980) Cochlear mechanics: nonlinear behaviour in two-tone responses as reflected in cochlear-nerve-fibre responses and in ear canal sound pressure. J.Acoust.Soc.Am. 67, 1704 - 1721.ADSCrossRefGoogle Scholar
  9. Smoorenburg, O.F. (1972) Audibility region of combination tones. J.Acoust.Soc.Am., 52, 603 - 614.ADSCrossRefGoogle Scholar
  10. Wilson, J.P. (1980) The combination tone, 2f1-f2, in psychophysics and ear canal recording. In ’Psychophysical, Physiological and Behavioural Studies in Hearing. eds. O. van den Brink & F.A. Bilsen. Delft Univ. Press, Delft, the Netherlands. pp 43 - 50.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • A. M. Brown
    • 1
  • S. A. Gaskill
    • 1
  1. 1.Laboratory of Experimental PsychologyUniversity of SussexFalmer, BrightonUK

Personalised recommendations