An integrated computational model of the auditory periphery for intracochlear electrocochleography applications

Electrocochleography (ECochG) measures electrical responses in the inner ear and is valuable for monitoring cochlear health during cochlear implantation. Yet, its interpretation is not straightforward, and available auditory models lack physiological detail and validity at high stimulus levels. We present the combined model of the peripheral auditory system (CPAS), which combines biophysical inner and outer hair cell models for ECochG simulation. Unlike previous hair cell models that focused on either cell type separately and output receptor potentials, CPAS directly computes extracellular currents without empirical scaling factors. The model couples a dual-resonance nonlinear basilar membrane filter with electrical hair cell circuits validated against animal data at multiple stimulus levels. CPAS is evaluated with ECochG simulations focused on high stimulus levels — the range at which intracochlear ECochG is clinically recorded. Simulated intracochlear ECochG responses demonstrate expected temporal, spectral, and spatial characteristics. CPAS provides a framework for ECochG modeling, and its biophysical parameters can in principle represent pathophysiological changes, providing a basis for future investigation of hearing impairment.