5aAA5. Audibility of individual reflections in a complete sound field, III.

Session: Friday Morning, December 6

Time: 9:15

Author: Soren Bech
Location: The Acoust. Lab. of the Tech. Univ. of Denmark


This paper reports on the influence of individual reflections on the auditory localization of a loudspeaker in a small room. Two previous papers [J. Acoust. Soc. Am. 97, 1717--1726 (1995); ibid. (in press)] have reported on the influence of individual reflections on timbre of reproduced sound. The sound field produced by a single loudspeaker positioned in a normal listening room has been simulated using an electroacoustical setup. The setup models the direct sound, 17 individual reflections, and the reverberant field. The threshold of detection was measured using the method of adjustment for five reflections using three subjects for noise and speech. The thresholds have been measured for two simulated situations: (1) A loudspeaker with frequency-independent directivity characteristics and frequency-independent absorption coefficients of the room surfaces and (2) a loudspeaker with directivity according to a standard two-way system and absorption coefficients according to real materials. The results have shown that subjects can reliably distinguish between timbre and localization, that the spectrum level above 2 kHz for individual reflections determines their influence on the localization of the main source, and that only the first-order floor reflection will contribute to localization of the main source. [sup a)]Present address: Bang and Olufsen A/S, Peter Bangs Vej 15, DK-7600 Struer, Denmark.

ASA 132nd meeting - Hawaii, December 1996