Head Movement Does Not Facilitate Perception of the Distance of a Source of Sound

Abstract

By actively moving his head a listener can increase the accuracy with which he localizes the source of a sound. There is good evidence for this when the listener is judging stimulus azimuth (Thurlow and Runge, 1967; Thurlow, Mangels, and Runge, 1967). Wallach (1940) presented a rationale for comparable facilitation in perceiving stimulus elevation, although subsequent empirical data have not always confirmed this (Roffler and Butler, 1968). Attempts to demonstrate facilitation from head movement in perceiving the distance of a sound's source have produced no such evidence. Yet Coleman's (1963) discussion of acoustic data from listening settings suggests that distance should be perceived more accurately by moving one's head. For distances of 15 ft or less, binaural differences in intensity and time of an arriving wavefront change with distance of the sound's source. Thus the particular pattern of binaural differences produced with head movement should specify the distance of that source.