ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4aPP11. Glide difference limens as a function of center frequency, duration, and transition size.

John P. Madden

Dept. of Commun. Disord., Univ. of North Dakota, University Station, Grand Forks, ND 58202-8040

The study determined glide difference limens for up and down glides in several conditions. Signal durations were 50, 100, and 400 ms, and the average stimulus center frequencies were 2 and 6 kHz. The standard, or comparison, signals changed in frequency by 0, 500, and 1000 Hz. These transition sizes were chosen to cover the range of F2 formant transitions. The subject's task was to distinguish between the standard and a target signal with a greater or lesser change in frequency, depending on the experimental condition, in a 2-alternative, forced-choice task. To avoid the confounding effect of between-stimuli static pitch cues, the center frequencies of the standard and target stimuli were ``roved'' about the center frequencies [Neill and Feth, J. Acoust. Soc. Am. Suppl. 1 87, S23 (1990)]. The data were analyzed using a level-detection model consisting of a filter bank, a nonlinearity, a temporal integrator, and a detection device. The question of whether the results support a rate place or temporal mechanism of frequency coding is discussed. [Work supported by NIDCD.]