Auditory motion induced by visual motion and its dependence on stimulus size

We examine whether visual motion induces a sensation of motion for a static sound in order to investigate dynamic visual-auditory interactions in the virtual environment. The dynamic interaural time difference (ITD) was employed as the cue for sound motion, and the effect of the size of the visual stimuli on biasing the perceived direction of dynamic ITD was examined As a result, induced motion sensation for static sound was obtained, and its direction was dependent on the size and direction of the applied visual stimuli. For a small visual stimuli (an 1-deg disk), sound with a static ITD moved in the same direction as the moving visual stimuli. For a large visual stimuli (a 90-deg random-dot pattern), however, sound with a static ITD moved to the opposite direction to that of the moving visual stimuli.