抄録
Obstacle sense is an experience-based ability to detect objects that generate no sound without using visual sense but using auditory sense. Detailing of the obstacle sense mechanism clearly is important in constructing systematic training to master this ability through education and rehabilitation of the blind, and the mechanism also can be applied to the acoustical VR technology that can presents the "silent objects" (eg., wall, pillar of building) virtually by "sound." This report covers psychological factors of obstacle sense to an infinite wall in a sound field consisting of plural circumstance noise. We assumed a sound field model having plural pairs of direct and reflected sounds. Three experiments were done: the first, a preliminary one, determined conditions of wall distance; the second examined sound image variation caused by the wall; and the third examined timbre variation caused by the wall. Results suggest that sound image variation caused by precedence effect is mainly psychological factor to detect an object at the side; timbre variation caused by coloration is mainly psychological factor to detect an object in front.
