Pitch strength of regular interval stimuli as a function of duration and filtering

Abstract

The ability of listeners to discriminate between a random interval noise and a regular interval stimulus, iterated rippled noise (IRN), was measured as a function of duration and bandpass filtering. IRN is generated by delaying (by d ms) a noise and adding it back to the undelayed noise after attenuation (g) in an iterative process (where n is the number of iterations). A two-alternative, forced-choice adaptive procedure was used in which stimulus duration was varied adaptively. Different values of g, d, n, and filter condition were used. In general, the duration required to discriminate IRN from regular interval noise increased as the filter condition provided less low-frequency energy. Duration thresholds were higher for high values of attenuation. The smallest duration thresholds were obtained for d in the range of 2–5 ms. The results will be discussed in terms of temporal models of the pitch of complex stimuli. [Work supported by NIDCD and AFOSR.]