Auditory mechanics of the tectorial membrane and the cochlear spiral.

Purpose Of Review: This review is timely and relevant because new experimental and theoretical findings suggest that cochlear mechanics from the nanoscale to the macroscale are affected by the mechanical properties of the tectorial membrane and the cochlea's spiral shape.

Recent Findings: Main tectorial membrane themes addressed in this review are composition and morphology, nanoscale mechanical interactions with the outer hair cell bundle, macroscale longitudinal coupling, fluid interaction with inner hair cell bundles, and macroscale dynamics and waves. Main cochlear spiral themes are macroscale, low-frequency energy focusing and microscale organ of Corti shear gain.

Summary: Recent experimental and theoretical findings reveal exquisite sensitivity of cochlear mechanical performance to tectorial membrane structural organization, mechanics, and its positioning with respect to hair bundles. The cochlear spiral geometry is a major determinant of low-frequency hearing. These findings suggest a number of important research directions.