A multicompartmental cochlear model with piezoelectric outer hair cells

Abstract

A hydromechanical, multicompartment model of the cochlea, which employed a phenomenological outer hair cell (OHC) cell‐body electro‐motility, was able to mimic the physiologically measured response of the basilar membrane (BM) [A. E. Hubbard et al., ‘‘Time‐domain responses from a nonlinear sandwich model of the cochlea,’’ in Biophysics of the Cochlea: From Molecule to Model, edited by A. W. Gummer (World Scientific, Singapore)]. An improved model that included OHC electro‐anatomic parameters and scalar electrical parameters was able to mimic cochlear microphonic (CM) data at low frequencies, but not BM responses at high‐frequencies, because the OHC membrane capacitance severely reduces OHC transmembrane potential. To improve the high‐frequency performance, we used a piezoelectrical model of the OHC. Consequently, the mechanical loading of the OHC translates bidirectionally with the electrical impedance of the OHC. The new model compares well with physiological data from Gerbil at 40 dB SPL [T. Ren and A. Nuttall, ‘‘Basilar membrane vibration in the basal turn of the sensitive gerbil cochlea,’’ Hearing Res. 151, 48–60 (2001)]. [This work was supported by NIH.]