ON EQUIVALENCE OF LOCALLY ACTIVE MODELS OF THE COCHLEA

Tn the literature on locally active models of the cochlea several form s of the model have been worked out in which elements of the organ of Corti are assumed to produce acoustical energy Tn these models use is made of a secondary resonance or a place-dependent delay to achieve ac tivity over a limited part of the length of the basilar membrane, and outer hair cells are postulated as sources of energy production. In th e present paper it will be shown that several of these models are form ally equivalent. That means that they can be reduced to a standard for m, and that the only difference resides in the choice and meaning of t he parameters. The results of the analysis serve to facilitate the ana lysis of function and structure in cochlear models containing sources of local activity. In particular, questions of positive versus negativ e feedback, and the parts played by resonance and impedance-level diff erences can be resolved unambiguously. The treatment can be extended t o models with higher dimensionality, and can also serve to obtain insi ght in nonlinear phenomena occurring in cochlear models. (C) 1995 Acou stical Society of America.