The influence of cochlear shape on low-frequency hearing
Title | The influence of cochlear shape on low-frequency hearing |
Publication Type | Journal Article |
Year of Publication | 2008 |
Authors | Manoussaki, D., R. S. Chadwick, D. R. Ketten, J. J. Arruda, E. K. Dimitriadis, and J. T. O' Malley |
Journal | Proceedings of the National Academy of Sciences |
Volume | 105 |
Start Page | 6162 |
Issue | 16 |
Pagination | 6162-6166 |
Date Published | 02/2008 |
Type of Article | Scientific |
Keywords | cochlea, cochlear spiral, function, inner ear, low frequency hearing, mammalian evolution, spiral |
Abstract | The conventional theory about the snail shell shape of the mammalian cochlea is that it evolved essentially and perhaps solely to conserve space inside the skull. Recently, a theory proposed that the spiral‘s graded curvature enhances the cochlea’s mechanical response to low frequencies. This article provides a multi-species analysis of cochlear shape to test this theory and demonstrates that the ratio of the radii of curvature from the outermost and innermost turns of the cochlear spiral is a significant cochlear feature that correlates strongly with low-frequency hearing limits. The ratio, which is a measure of curvature gradient, is a reflection of the ability of cochlear curvature to focus acoustic energy at the outer wall of the cochlear canal as the wave propagates toward the apex of the cochlea. |