Abstract:

Many stimuli that contain regular temporal intervals are perceived as having a pitch equal to the reciprocal of the interval. Autocorrelation is one method of determining the interval in these regular interval stimuli (RIS). Autocorrelation analysis has been used as a ``model'' for calculating the pitch and pitch strength of RIS. Autocorrelation is an ``all-interval'' analysis as opposed to the first-order interval analysis that is often used to describe the temporal properties of neural spike trains. Both actual neural responses (from the AVCN of the chinchilla) and those of a simple neural model were measured to determine the order of intervals contained within RIS. In a psychoacoustic experiment, RIS were generated with no first-order intervals or with only first-order intervals, and listeners discriminated between these stimuli and stimuli with no regular intervals. The results of the experiments and the calculations indicate that the pitch and pitch strength of RIS probably depend on only lower-order intervals (no higher than fourth-order intervals). These results will be discussed in terms of theories of pitch and timbre processing. [Work supported by NIDCD, DC-00293.]