Reverse transduction measured in the isolated cochlea by laser Michelson interferometry

Amplification of sound inside the cochlea of the ear of an amphibian, which is affected by sensory and outer hair cells, determines the sensitivity of mammalian hearing. Displacements and feedback forces, which increase basilar membrane motion by reducing the inherent damping, are caused by these cells. Hair cells also exhibit membrane-potential-induced length changes-which indicates that the cells are capable of amplifying sound. The investigation is performed by using a displacement sensitive interferometer.