Magnitude of Distortion-Product Oaes in a Nonlinear Model of the Cochlea

The primary site of generation on the basilar membrane of the 2f₁-f₂ component of the distortion product otoacoustic emission (DPOAE) is generally considered to be in the region of overlap of the primary tones. The present study was designed to expect the amplitude of DPOAEs using a 1-D transmission line model of the human cochlea. The following features of 2f₁-f₂ DPOAE listed below were well explained by computing the summation of the primaries between f₁ and f₂ places.

1. With increasing L₁=L₂ stimulus tones, 2f₁-f₂ DPOAE increases in amplitude at a growth rate of around 1 dB/dB.

2. In cases of outer hair cell (OHC) impairment, the DPOAE amplitude is reduced and the slope of the DPOAE input/output function is steep compared to the normal cases.

3. The amplitude of DPOAEs is larger at 2f₁-f₂ than at 2f₂-f₁.

4. L₁ amplitude of about 10 dB louder than L₂ evoked the strongest DPOAE.