Journal of comparative physiology

, Volume 102, Issue 4, pp 321–336

Frequency and intensity difference limens and nonlinearities in the ear of the housemouse (Mus musculus)

  • Günter Ehret
Article

DOI: 10.1007/BF01464344

Cite this article as:
Ehret, G. J. Comp. Physiol. (1975) 102: 321. doi:10.1007/BF01464344

Summary

  1. 1.

    Frequency and intensity difference limens were determined for the housemouse (Mus musculus, outbred strain NMRI) between 1 kHz and 80 kHz and for sound pressure levels (SPLs) between 15 dB and 100 dB re. 0.0002 dyn/cm2.

     
  2. 2.

    The frequency difference limens (Δfs) decrease linearly with increasing SPL. The slopes (a) of the regression lines are frequency dependent (¦a¦=p·/tfq;p andq are constants) with ¦a¦ being maximal at 15 kHz. An intensity independent level of the smallest noticeable frequency differenceΔfm is reached at a definite SPL (LΔfm) which is always 60 dB above the absolute hearing threshold (LHS) at each frequency tested (LΔfm-LHS=const.). The relative frequency difference limenΔfm/f was nearly constant and equal to 0.85%.

     
  3. 3.

    The intensity difference limens (ΔLs) decrease with increasing SPL. The interdependence can be approximated by a linear or a power function (ΔLs=−0.05·SL+7;ΔLs=0.04· SL+120·SL−1; SL=sensation level). The difference limens (ΔLs) are frequency dependent (ΔLs=d·fe·SL) at low sensation levels. The equationΔI=g·I0.95 (I=sound intensity) shows a near miss of Weber's law. The relative averaged difference limen (ΔLs/SL) amounts to 6.7% at 60 dB SL.

     
  4. 4.

    The results agree well with a model of a spectrum-excitation-transformation on the basilar membrane (Maiwald, 1967). In addition, a new frequency dependent nonlinearity of the mammalian ear is defined. It influences frequency and intensity discrimination in the same manner and can be expressed in a power function of the frequency summarized in the proportion:Δf∼ΔLsfz·L.

     
  5. 5.

    Comparative aspects of difference limens in man and other mammals are discussed.

     

Copyright information

© Springer-Verlag 1975

Authors and Affiliations

  • Günter Ehret
    • 1
  1. 1.Fachbereich Biologie (Zoologie) der Technischen HochschuleDarmstadtGermany
  2. 2.Fachbereich BiologieUniversität KonstanzGermany

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