ASA 125th Meeting Ottawa 1993 May

4aPP8. The growth of loudness of brief sounds.

Mary Florentine

Commun. Res. Lab., Dept. of Speech-Language Pathol. and Audiol., 133FR, Northeastern Univ., Boston, MA 02115

Soren Buus

Northeastern Univ., Boston, MA 02115

Torben Poulsen

Tech. Univ. of Denmark, DK-2800 Lyngby, Denmark

The purpose of this paper is to review the literature on temporal integration of loudness and to derive the form of the loudness function for brief stimuli from existing data. The review of 19 studies reveals that the level difference between equally loud sounds of different durations varies with overall level. The variation is orderly across durations. For 1-kHz tones, the level differences between equally loud 5- and 200-ms stimuli appears to vary nonmonotonically with level. The available data indicate that it ranges from about 17 dB at low sensation levels to about 10 dB around 95 dB SL. For complex sounds, the level difference between equally loud 5- and 200-ms stimuli appears to decrease linearly from about 17 dB at low sensation levels to about 10 dB around 80 dB SL. The loudness functions derived for 5-ms stimuli are steeper than those for 200-ms stimuli. For the 1-kHz tones, the exponent of the best-fitting power function increases from 0.30 for 200-ms tones to 0.33 for 5-ms tones. [Work supported by NIH-NIDCD and The Technical University of Denmark.]