A demonstration of peripheral constraint on an auditory duration discrimination task

Abstract

An earlier study investigated the discrimination of auditory durations presented at a rapid rate in a two‐alternative forced‐choice task. The results indicated that a constant Weber fraction was obtained across base durations from 25–1600 ms if a long interstimulus interval (ISI) separated the two alternative presentations, but performance degraded with short base durations if a short ISI was used [B. R. Shelton, J. Acoust. Soc. Am. Suppl. 1 72, S89 (1982)]. Here, the same measurements were taken under two presentation conditions: (1) a binaural presentation of both intervals, and (2) a monaural presentation of the two intervals, each to a different ear. Base durations of 25, 50, 100, and 200 ms were used, with ISI values of 25, 50, 100, 200, 400, 800, and 1600 ms. The binaurally presented condition replicated the previous results, but the presentation of intervals to alternate ears produced a marked improvement in performance, especially with short ISI presentations. This finding suggests that the discrimination of the duration of rapidly presented auditory stimuli is restricted peripherally. [Work supported by NSERC.]