Abstract
Recent developments in virtual 3D audio and synthetic aural environments have produced a complex acoustical
room simulation. The acoustical simulation models a room with walls, ceiling, and floor of selected sound
reflecting/absorbing characteristics and unlimited independent localizable sound sources. This non-visual
acoustic simulation, implemented with 4 audio ConvolvotronsTM by Crystal River Engineering and coupled to
the listener with a Poihemus IsotrakTM, tracking the listener's head position and orientation, and stereo
headphones returning binaural sound, is quite compelling to most listeners with eyes closed. This immersive
effect should be reinforced when properly integrated into a full, multi-sensory virtual environment
presentation.
This paper discusses the design of an interactive, visual virtual environment, complementing the acoustic model
and specified to: 1) allow the listener to freely move about the space, a room of manipulable size, shape, and
audio character, while interactively relocating the sound sources; 2) reinforce the listener's feeling of
telepresence into the acoustical environment with visual and proprioceptive sensations; 3) enhance the audio
with the graphic and interactive components, rather than overwhelm or reduce it; and 4) serve as a research
testbed and technology transfer demonstration. The hardware/software design of two demonstration systems,
one installed and one portable, are discussed through the development of four iterative configurations. The
installed system implements a head-coupled, wide-angle, stereo-optic tracker/viewer and multi-computer
simulation control. The portable demonstration system implements a head-mounted wide-angle, stereo-optic
display, separate head and pointer electro-magnetic position trackers, a heterogeneous parallel graphics
processing system, and object oriented C++ program code.
