Waves on Reissner's membrane: a mechanism for the propagation of otoacoustic emissions from the cochlea

TL;DR

This paper demonstrates that waves on Reissner's membrane facilitate the propagation of otoacoustic emissions from the cochlea, combining theoretical modeling with experimental measurements across multiple species.

Contribution

It introduces a new theory for wave propagation on Reissner's membrane and provides experimental evidence supporting its role in otoacoustic emissions.

Findings

Waves on Reissner's membrane are observed in multiple species.

Theoretical and experimental results are in agreement.

Reissner's membrane plays a role in otoacoustic emission propagation.

Abstract

Sound is detected and converted into electrical signals within the ear. The cochlea not only acts as a passive detector of sound, however, but can also produce tones itself. These otoacoustic emissions are a striking manifestation of the cochlea's mechanical active process. A controversy remains of how these mechanical signals propagate back to the middle ear, from which they are emitted as sound. Here we combine theoretical and experimental studies to show that mechanical signals can be transmitted by waves on Reissner's membrane, an elastic structure within the cochea. We develop a theory for wave propagation on Reissner's membrane and its role in otoacoustic emissions. Employing a scanning laser interferometer, we measure traveling waves on Reissner's membrane in the gerbil, guinea pig, and chinchilla. The results accord with the theory and thus support a role for Reissner's membrane in otoacoustic emissions.