Abstract:

Immersive, multisensory displays are increasingly a goal of advanced human--machine interfaces, and three-dimensional sound techniques are now practical enough to be applied to these displays. The goal of virtual acoustics is to simulate the complex acoustic field experienced by a listener freely moving within an environment. Of course, such complexity, freedom of movement, and interactivity is not always possible in a ``true'' virtual environment, much less in lower-fidelity multimedia systems. Many of the perceptual and engineering constraints (and frustrations) that researchers, engineers, and listeners have experienced in virtual audio are relevant to multimedia. In fact, some of the problems that have been studied will be even more of an issue for lower fidelity systems that address the requirements of a large, diverse, and ultimately unknown audience. Examples include individual differences in head-related transfer functions, a lack of real interactivity in many multimedia systems, and perceptual degradation due to low-sampling rates or compression. This paper discusses some of the engineering constraints and perceptual consequences faced during implementation of virtual acoustic displays for NASA applications such as aeronautics and shuttle launch communications. An attempt is also made to relate these issues to low-fidelity applications such as the Internet.