A physiologically-based time domain model of the mammalian ear

Abstract

Abstract. In this paper, we present a physiologically-based time-domain model of the mammalian ear that couples a nonlinear model of the cochlea with a lumped parameter model of the middle ear. The cochlear model is an extension of a previous nonlinear frequency-domain model [9]. This model is based on the finite element method and includes mechanical degrees of freedom for the organ of Corti micromechanics, acoustical degrees of freedom for the intracochlear fluid mechanics and electrical degrees of freedom that represent the intracellular outer hair cell (OHC) potential and the electrical potentials in the cochlear ducts. Nonlinear OHC hair bundle mechanoelectrical transduction and linear somatic electromotility couple the mechanical and electrical domains of the cochlea. A two-dimensional representation of the fluid domain is used. The governing equations are formulated using a state-space approach that is used to determine the linear stability and the timedomain response of the model. Electrical longitudinal cables were previously included in the frequency-domain model in order to represent the propagation of current in the cochlear ducts. The effect of these cables on the state-space formulation is discussed. Numerical results for the transient and steady-state response to a pure tone are presented.