Temporal aspects of pitch perception at high and low S/N ratios

Abstract

The study investigated the integration of nonsimultaneous frequency components into a single pitch in quiet and in noise. Using a pitch matching paradigm, the shifts produced by a mistuned harmonic in the pitch of a target complex were measured either with a pre-target component (when the mistuned component stopped as the target started) or with a post-target component (when the mistuned component immediately followed the target tone) [J. Acoust. Soc. Am. 98, 2946(A) (1995)]. The stimuli were presented in quiet or in the presence of a band of noise, low-pass filtered at a frequency cutoff of 3 kHz (approx. −23-dB S/N ratio around the frequency of the mistuned component). In quiet, post-target and simultaneous mistuned components produced larger pitch shifts than pre-target components. In noise, shifts in the pre-target condition were identical to those produced by simultaneous and post-target components. The duration of the interval which separated the nonsimultaneous components and the target tone was varied in a second experiment. The results suggest that the period over which nonsimultaneous components contribute to the pitch of the target is longer in noise than in quiet for both pre- and post-target conditions. [Work supported by HKRGC Grant No. HKU362/94M.]