Distortion product emissions from a cochlear model with nonlinear mechanoelectrical transduction in outer hair cells

Abstract

A model of cochlear mechanics is described in which force-producing outer hair cells (OHC) are embedded in a passive cochlear partition. The OHC mechanoelectrical transduction current is nonlinearly modulated by reticular-lamina (RL) motion, and the resulting change in OHC membrane voltage produces contraction between the RL and the basilar membrane (BM). Model parameters were chosen to produce a tonotopic map typical of a human cochlea. Time-domain simulations showed compressive BM displacement responses typical of mammalian cochleae. Distortion product (DP) otoacoustic emissions at 2f1−f2 are plotted as isolevel contours against primary levels (L1,L2) for various primary frequencies f1 and f2 (f1