On ringing limits of the auditory periphery.

In classical hearing theory frequency and time have been treated as nearly independent acoustical dimensions. In this paper the interaction between temporal and spectral aspects is studied. An important determinant in this respect is the filtering of auditory stimuli in the cochlea. A view of auditory filtering that is balanced in frequency and time is obtained from the 'reverse-correlation function', abbreviated: revcor function. This function is derived from the response of an auditory-nerve fibre to a white-noise sound stimulus. It is a useful descriptor of peripheral filtering for a wide class of stimuli in which effects of nonlinear distortion are of minor importance. Measured revcor functions can be approximated by a standard mathematical function of which the parameters have a clear meaning. For these functions the spread in time and in frequency are uniquely related to one another. This relation is carried over to the case of cochlear filtering and applied to two important cases: stimulation by signals with small and with large amplitude variations. The results turn out to be markedly different in these two cases. In the final section the relevance of the results to various other fields of auditory research is discussed.