ASA 125th Meeting Ottawa 1993 May

2pPP29. Relative auditory distance perception of synthetic reflections and reverberation presented over headphones.

William R. D

M. A. Ericson

AL/CFBA Bldg. 441, 2610 Seventh St., Wright Patterson AFB, OH 45433-7901

Relative auditory distance perception of a direct path signal by itself, with synthetic reflection(s), and with reverberation presented over headphones was measured using a 2AFC task. The stimulus, either a 500-ms pink noise burst or a 3-s phrase of male speech, was presented twice, first at a reference distance and second at an incremental distance from the reference. Reference distances included 5, 14, and 22 ft, and the incremental distances included multiples of 0.125, 0.25, and 0.5 ft, respectively. Stimuli pairs at each of the three distances were presented from four directions: front, back, left, and right. For each stimuli pair, the task of eight subjects was to indicate which of the two sounds appeared closer to himself/herself. The results of all locations indicated that the jnds for the direct path signal were 7%, jnds for the reflections were around 6%, and jnds for the reverberant sounds were about 12%. All of the sounds appeared out-of-head, however, almost all of the sounds presented from behind were perceived to be in front. Side sounds appeared to be biased towards the front when presented at the further distances.