A Virtual Display System for Conveying Three-Dimensional Acoustic Information

A three-dimensional auditory display could take advantage of intrinsic sensory abilities like localization and perceptual organization by generating dynamic, multidimensional patterns of acoustic events that convey meaning about objects in the spatial world. Applications involve any context in which the user's situational awareness is critical, particularly when visual cues are limited or absent; e.g., air traffic control or telerobotic activities in hazardous environments. Such a display would generate localized cues in a flexible and dynamic manner. Whereas this can be readily achieved with an array of real sound sources or loudspeakers, the NASA-Ames prototype maximizes flexibility and portability by synthetically generating three-dimensional sound in realtime for delivery through headphones. Psychoacoustic research suggests that perceptually-veridical localization over headphones is possible if both the direction-dependent pinna cues and the more well understood cues of interaural time and intensity are adequately synthesized. Although the realtime device is not yet complete, recent studies at the University of Wisconsin have confirmed the perceptual adequacy of the basic approach to synthesis.