The Influence of Outer Hair Cells on Tectorial Membrane Waves

The cochlea, a vital structure for hearing, comprising the scala media, scala tympani, and scala vestibuli, separated by Reissner’s and basilar membranes. The scala media houses the organ of Corti, containing inner and outer hair cells (IHCs and OHCs). Extensive research has explored OHCs, focusing on their mechanical properties and role in cochlear mechanics. This study investigates the impact of OHCs on two types of tectorial membrane (TM) slow waves, termed TM wave 1 and TM wave 2, using modal analysis. The research utilizes a model incorporating the basilar membrane, TM, and OHCs. The study explores how OHCs influence the propagation characteristics of these waves. Results demonstrate that OHCs affect TM wave 1 minimally, with distinctions becoming negligible at higher frequencies. In contrast, OHCs significantly influence TM wave 2, especially in the high-frequency range. The study further explores the frequency-dependent phase and attenuation constants of these waves, revealing substantial effects of OHCs on TM wave 2 across different frequencies and TM widths.