ASA 127th Meeting M.I.T. 1994 June 6-10

3aPP19. Distance information transmission using first-order reflections.

Douglas S. Brungart

N. I. Durlach

Res. Lab. of Electron., Rm. 36-769, MIT, 77 Massachusetts Ave., Cambridge, MA 02139

An experiment is underway to determine the viability of synthetic first-order room reflections as a source of audio distance information for virtual environments. Although reflections have been considered possible sources of audio distance cues in real environments for some time, little basic research has been done to determine the ability of human listeners to identify the relative intensity of the primary and reflected signals and the time delay between the primary and reflected signals. A preliminary experiment showed little improvement in distance identification with the addition of a single-floor reflection when a distance cue based on the overall intensity of the signal was present. A second experiment has been designed that examines the amount of information transfer that can be achieved through variations in the delay and the relative intensity of the reflection when the overall intensity of the signal is randomized. The results of these experiments are discussed, along with the implications of these results for the implementation of reflection-based audio cues in virtual environments.