Journal of comparative physiology

, Volume 123, Issue 3, pp 205–216 | Cite as

Biophysics of the ensiferan ear

II. The steady-state gain of the hearing trumpet in bushcrickets
  • Clive Seymour
  • Brian Lewis
  • Ole N. Larsen
  • Axel Michelsen
Article

Summary

  1. 1.

    A method for determining the steady-state gain in the tracheal hearing trumpet in bushcrickets is described: The expected change in force, caused by moving the front leg from one position to another (Fig. 1) can be calculated (Figs. 2 and 3), assuming a certain gain. Laser vibrometry is used for determining the velocity of a tympanal membrane in the two leg positions. The observed change in velocity (Figs. 4 and 5) can then be compared with the calculated change. The approximate gain is determined as a ‘best fit’ between the two sets of data.

     
  2. 2.

    The steady-state gain is about 1 at 1–3 kHz and about 2 at higher frequencies.

     
  3. 3.

    The change in the threshold of the ear, caused by moving the leg, is measured by recording from the auditory nerve (Fig. 6). The steady-state gain thus determined is of the same order of magnitude as that determined by means of laser vibrometry.

     
  4. 4.

    The scattering of sound waves around a cylindrical obstacle has been studied, in order to estimate the magnitude of the local variations in sound pressure at some distance from the body of an insect (Figs. 7 and 8).

     
  5. 5.

    The experimental evidence supporting the Zeuner-Nocke theory for the bushcricket ear is discussed.

     

Keywords

Experimental Evidence Local Variation Sound Pressure Sound Wave Auditory Nerve 

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References

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Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • Clive Seymour
    • 1
  • Brian Lewis
    • 1
  • Ole N. Larsen
    • 2
  • Axel Michelsen
    • 2
  1. 1.Animal Acoustics UnitCity of London PolytechnicLondonEngland
  2. 2.Institute of BiologyOdense UniversityOdense MDenmark

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