title: The spiral staircase: tonotopic microstructure and cochlear tuning.
abstract: Although usually assumed to be smooth and continuous, mammalian cochlear frequency-position maps are predicted to manifest a staircase-like structure comprising plateaus of nearly constant characteristic frequency separated by abrupt discontinuities. The height and width of the stair steps are determined by parameters of cochlear frequency tuning and vary with location in the cochlea. The step height is approximately equal to the bandwidth of the auditory filter (critical band), and the step width matches that of the spatial excitation pattern produced by a low-level pure tone. Stepwise tonotopy is an emergent property arising from wave reflection and interference within the cochlea, the same mechanisms responsible for the microstructure of the hearing threshold. Possible relationships between the microstructure of the cochlear map and the tiered tonotopy observed in the inferior colliculus are explored.
authors: Eaton-Peabody Laboratories, Massachusetts Eye and Ear, Boston, Massachusetts 02114 christopher.shera@gmail.com.
authors: Christopher A
authors: http://orcid.org/0000-0002-5939-2710
authors: CA
authors: Shera
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology*; D002415:Cats; D003051:Cochlea / Q000033:anatomy & histology* / Q000502:physiology*; D007245:Inferior Colliculi / Q000033:anatomy & histology / Q000502:physiology; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology
keywords: basilar membrane; cochlear tonotopy; frequency selectivity; inferior colliculus; otoacoustic emissions