Auditory singularity detection by a gerbil cochlea model

A singularity event in an acoustic waveform typically produces at most one extra spike in any cochlear neuron, but the synchrony of such spikes over a subpopulation often yields a distinct (whole-nerve) compound action potent ial, or CAP (Lewis and Henry, Hear. Res. 39 (1989) 209-224). Thus, while a single extra spike among the spontaneous spikes in one neuron seems insuffi cient to encode the event, the widespread spike synchrony implied by the CA P should provide very secure encoding. To examine how such a code might be distributed over a tonotopically organized ensemble of afferent axons, we h ave constructed a cochlear model from experimental gerbil data and computed the neural spectrograph produced in response to various kinds of singulari ties. (C) 2000 Elsevier Science B.V. All rights reserved.