Interdependence between temporal and ambient spatial variations of a successive sound sequence

Time and space are interdependent in perception. The most typical example is that the temporal and spatial patterns of three successive stimuli, defining two inter-onset intervals and two spatial distances, can respectively affect the experience of spatial and temporal variations. In regard to auditory modality, most studies have equated pitch space with ambient space and demonstrated that each of the temporal and pitch intervals can affect the respective perceptual pitch and temporal variations. A very interesting question is whether the interdependence between temporal and ambient spatial variations, not pitch variations, could be found when successive sounds differ in location. To investigate what effect temporal variations in a successive sound sequence had on the experience of spatial variations, we measured the subjective differences between two neighboring distances (Experiment 1) and subjective absolute locations (Experiment 2) when three successive sounds, S1, S2, and S3, were presented to participants from different loudspeakers. The results demonstrated that varying the time interval between S1 and S2 (t1) and between S2 and S3 (t2) affected the perceived spatial distances between the sounds. If t1 was larger than t2, the subjective distance between S1 and S2 (d1) was greater than that between S2 and S3 (d2), although the physical distances of d1 and d2 were identical. The results indicate that there is a typical Tau effect in auditory modality, and the auditory Tau effect is caused by the mislocalization of S2. Furthermore, the findings suggest that a perceptual, not physical, temporal pattern affects the experience of the auditory spatial layout. Spatial information on successive sounds may be organized after a sound sequence is temporally structured.