Directional dependence of the change of auditory source width by very short time-delay reflections

Abstract

Barron [J. Sound Vib. 15, 475–494 (1971)] showed that spatial impression (SI) corresponding to auditory source width (ASW) decreases when the time delay of reflections relative to the direct sound is shorter than 10 ms. This paper investigates the effect of the direction of lateral reflections on the decrease of ASW. The music motif used in this investigation was a 6.5-s section of the 4th movement of Mozart’s Jupiter Symphony (No. 41), which was the same motif as Barron used. The sound fields used as stimuli consisted of a direct sound and two discrete reflections with a 1-ms interval between them. The time-delay of the first reflection relative to the direct sound was 2, 4, or 8 ms. The directions of the reflections were ±18°, ±45°, or ±72°. The experimental results demonstrate that the decrease of ASW depends on the direction of the reflections. As the reflections arrive from a more frontal direction, ASW decreases more sharply relative to the delay time.