ASA 127th Meeting M.I.T. 1994 June 6-10

4pPP1. On the relation between spectral discrimination of wideband and narrow-band sounds.

Dept. of Cognitive Sci., School of Social Sci., Univ. of California, Irvine, CA 92717

The relation between listener's abilities to discriminate spectral changes in wideband sounds and spectral changes in narrow-band sounds is examined. The standard in a 2IFC task consists of five, equal-intensity tones; the signal consists of an increment in the intensity of the central tone. Overall intensity is varied over a 20-dB range using a roving level procedure. Component frequencies are 200, 450, 1000, 2240, and 5000 Hz in the wideband condition, and 980, 990, 1000, 1010, and 1020 Hz in the narrow-band condition. Threshold estimates for 12 listeners show that performance levels in the two conditions are negatively correlated. Additional results suggest that listeners having the highest thresholds in the wideband condition extract envelope information over a greater range of frequencies than do listeners having the lowest thresholds. Theoretical implications concerning individual differences and an apparent trade-off in the ability to process acoustic information in temporal and spectral domains are discussed. [Work supported by ONR.]