Consideration on the Mechanics of the Combination Tones

Abstract

1) We investigated the dependence of the 2f₁-f₂ level on the stimulus level with primary-tone levels equal. Our results showed that 2f₁-f₂ level grew with a slope near 1 when both primary-tone levels increase. Many investigators have pointed out that the observed slope is near 1 in the psychoacoustical examination. This result seems to be explained by the overlap of the excitation patterns of f₁ & f₂, assuming the saturating mechanics in vibration amplitude of the basilar membrane.
2. It is considered that the combination tone 2f₁-f₂ is generated by the nonlinear motion of the basilar membrane, and can indicate the inner-ear function. But it must be proved that the measurement system does not generate the 2f₁-f₂ tone in this investigation.