title: Frequency selectivity without resonance in a fluid waveguide.
abstract: This study analyzes a waveguide consisting of two parallel fluid-filled chambers connected by a narrow slit that is spanned by two coupled elastic beams. A stiffness gradient exists in the longitudinal direction. This simple linear system, which contains no lumped mass, is shown to act as a spectral analyzer. Fluid waves traveling in the waveguide exhibit a distinct amplitude peak at a longitudinal location that varies systematically with frequency. The peaking is not based on resonance, but entirely on wave dispersion. When entering its peak region, the wave undergoes a sharp deceleration associated with a transition in which two propagation modes exchange roles. It is proposed that this mode shape swapping underlies the frequency analysis of the mammalian cochlea.
authors.affiliation: Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, 3000 CA, Rotterdam, The Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: van der Heijden
mesh_terms: D000161:Acoustic Stimulation / Q000295:instrumentation / Q000379:methods; D000465:Algorithms; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology; D003051:Cochlea / Q000502:physiology*; D006309:Hearing / Q000502:physiology*; D008954:Models, Biological; D013016:Sound
keywords: auditory filter; avoided crossing; group velocity; hydrodynamics; tonotopy