Accession Number : ADA304596

Title :   NPSNET-3D Sound Server. An Effective Use of the Auditory Channel.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Storms, Russell L.

PDF Url : ADA304596

Report Date : SEP 1995

Pagination or Media Count : 191

Abstract : The current MIDI-based sound system for the distributed virtual environment of NPSNET can only generate aural cues via free field format in two dimensions. To increase the effectiveness of the auditory channel in NPSNET, a sound system is needed which can generate aural cues via free field format in three dimensions. The approach taken was to build upon the current NPSNET sound system: NPSNET-PAS ROES94. Hardware limitations of NPSNET-PAS sound generating equipment were identified and more capable off the shelf sound equipment was procured. In software, a new algorithm was developed which properly distributes the total volume of a virtual sound source to a cube like configuration of eight loudspeakers. A second algorithm, based on the Precedence Effect, was also developed in an attempt to enhance one's ability to localize a sound source. Synthetic reverberation using digital signal processors was added to enhance perceptual distance of the generated aural cues. The result of this research is a MIDI-based free field sound system consisting of off the shelf' sound equipment and computer software capable of generating aural cues in three dimensions for use in NPSNET. This sound system was tested during numerous demonstrations of NPSNET and proved capable of generating eight independent audio channels required for potential output to a cube like configuration of eight loudspeakers laying the foundation for increasing one's level of immersion in NPSNET.

Descriptors :   *THREE DIMENSIONAL, *ACOUSTIC EQUIPMENT, *AUDITORY PERCEPTION, COMPUTER PROGRAMS, ALGORITHMS, SIGNAL PROCESSING, DIGITAL SYSTEMS, LIMITATIONS, RANGE(DISTANCE), REVERBERATION, CHANNELS, IMMERSION, LOUDSPEAKERS, HEARING, SOUND GENERATORS, PHONOGRAPHS.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE