Enhancement of Audio Localization Cue Synthesis by Adding Environmental and Visual Cues

An audio localization cue synthesizer, the DIRectional Audio Display DIRAD was used to simulate auditory distance, room reflections, and to provide spatial audio for computer graphics images. The DIRAD processes input audio signals to generate spatially located sounds for headphone listening. The DIRAD can position audio sources around the head and these sounds are stable with respect to the listeners head position. An interactive, real-time simulation of auditory distance and room reflections was accomplished using the DIRAD in combination with a Silicon Graphics audio processor board installed in a Personal Iris 4D35. Several demonstrations of auditory distance and the effects of early reflections are detailed, including a simulation of a direct sound source and three reflections that employed two DIRAD systems. Stored sound files were used to accompany three dimensional graphics images that were displayed on both a Silicon Graphics CRT and a three dimensional optical display device. The use of the 4D35 audio processor board proved to be an effective means of preprocessing audio for the DIRAD for these simulations. The combination of AFITs Silicon Graphics workstations and the DIRAD proved to be a practical solution to the problem of combining virtual visual and audio cues....Auditory localization, Auditory perception, Virtual reality, 3-D Audio, Acoustic reflection, Sound equipment.