Stationary solution for distortion-products in two-dimensional cochlear model with inhomogeneities

Abstract

Vetesnik and Gummer [J. Acoust. Soc. Am. 131, 3914–3934 (2012)] obtained a stationary solution for distortion products (DPs) in a two-dimensionalcochlear model in which the impedance of the basilar membrane varied smoothly along its length. Their solution was used to study the dependence of the nonlinear-distortion source of distortion-product otoacoustic emission (DPOAE) on stimulus level [Vencovský et al., J. Acoust. Soc. Am. 145, 2909–2931 (2019); Vencovský et al., J. Acoust. Soc. Am. 146, EL92–EL98 (2019)]. Here, the solution is extended to “impedance irregularities” in the mechanics of the cochlea causing the generation of the coherent-reflection source of DPOAEs near the DP characteristic place. The coherent-reflection source of DPOAEs can be relatively pronounced in normal-hearing humans and the interference between the nonlinear-distortion and coherent-reflection components complicates the use of DPOAEs in routine clinical screening of the auditory periphery. The solution for the model with mechanical perturbation can be used to study the relationship between nonlinear-distortion and coherent-reflection components of DPOAEs.