title: The influence of cochlear shape on low-frequency hearing.
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 multispecies 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.
authors.affiliation: Department of Mathematics, Vanderbilt University, Nashville, TN 37240, USA.
authors.forename: Daphne
authors.initials: D
authors.lastname: Manoussaki
authors.forename: Richard S
authors.initials: RS
authors.lastname: Chadwick
authors.forename: Darlene R
authors.initials: DR
authors.lastname: Ketten
authors.forename: Julie
authors.initials: J
authors.lastname: Arruda
authors.forename: Emilios K
authors.initials: EK
authors.lastname: Dimitriadis
authors.forename: Jen T
authors.initials: JT
authors.lastname: O'Malley
mesh_terms: D000818:Animals; D002417:Cattle; D006168:Guinea Pigs; D006309:Hearing / Q000502:physiology*; D006801:Humans; D051379:Mice; D008954:Models, Biological; D009925:Organ of Corti / Q000033:anatomy & histology* / Q000166:cytology / Q000502:physiology*; D011817:Rabbits; D051381:Rats; D013016:Sound