Relationship between DPOAE and pure tone hearing levels: Numerical analysis with human cochlear finite element model

Dysfunction of the outer hair cells (OHCs) is thought to lead to hearing loss. However, direct diagnosis of the OHC dysfunction is difficult, and the activity of the OHC is indirectly estimated by measuring distortion product otoacoustic emissions (DPOAEs). In this study, a finite-element model of the normal cochlea considering the activity of the OHC and hearing impairment models in which the activity of the OHC was partially absent were constructed. A pure tone or a complex tone was applied to the models, and the relationship between DPOAE level and non-active portion on the basilar membrane was investigated. As a result, it was speculated that the dysfunction of the OHC at the basal side of the position of the characteristic frequency for the input frequency affects pure tone hearing and DPOAE levels.