Lance Nizami
Bruce A. Schneider
Dept. of Psychol., Erindale College, Univ. of Toronto, 3359 Mississauga Rd., Mississauga, ON L5L 1C6, Canada
Recovery rates differ significantly [E. M. Relkin and J. R. Doucet, Hear. Res. 55, 215--222 (1991)] for nerve fiber groups believed to be separate channels for loud and soft sounds [e.g., Winslow et al., in Auditory Processing of Complex Sounds (Erlbaum, Hillsdale, NJ, 1987), pp. 212--224]. Such differences could produce two distinct portions in the auditory recovery curve. Forward-masked detection thresholds were obtained from three experienced listeners using a two-interval forced-choice task, at masker-target time gaps (recovery times) of 0--10 ms with a resolution of 1 ms or less. The masker, a 97 dB SPL, 2-kHz, 200-ms tone, preceded a 2-kHz Gaussian-shaped tone pip ((sigma)=0.5 ms). A cusp appeared in the curve relating forward-masked thresholds to recovery time at 3--6 ms, indicating that recovery followed a two-part decay curve. Forward-masked thresholds rise over 0--2 ms replicating a pattern found earlier [H. Duifhuis, J. Acoust. Soc. Am. 54, 1471--1488 (1973); M. J. Penner, J. Acoust. Soc. Am. 56, 179--182 (1974)]. [Work supported by NSERC.]