A model cochlear partition involving longitudinal elasticity.

This paper addresses the issue of longitudinal stiffness within the cochlea. A one-dimensional model of the cochlear partition is presented in which the resonant sections are coupled by longitudinal elastic elements. These elements functionally represent the aggregate mechanical effect of the connective tissue that spans the length of the organ of Corti. With the plate-like morphology of the cochlear partition in mind, the contribution of longitudinal elasticity to partition dynamics is appreciable, though weak and nonlinear. If the elasticity is considered Hookian then the nonlinearity takes a cubic form. Numerical solutions are presented that demonstrate the compressive nature of the partial differential nonlinear equations and their ability to produce realistic cubic distortion product otoacoustic emissions. Within the framework of this model, some speculations can be made regarding the dynamical function of the phalangeal processes, the sharpness of active cochlear mechanics, and the propogation of pathology along the partition.