Researchers in California have created a new, publicly available database of acoustic measurements of human subjects that may help engineers build personalized sound systems for computers that could rival or even exceed the experience of listening to a high-end home theater system.
Richard Duda and V. Ralph Algazi of the University of California, Davis said the database could have a wide range of applications, including teleconferencing, mobile computing and home entertainment. The National Science Foundation (NSF) funded their work.
"One day," said Algazi, "computer users could operate a small, 'wearable' computer using voice commands, with spatial sound replacing a visual display." He added that the database could aid in the development of "immersion" systems that could allow scientists to interact with their data in a computer-generated, three-dimensional space incorporating both images and sound.
People use a number of complex sound cues to experience their surroundings. But reproducing these cues accurately is a difficult technical problem. The cues that stem from the complex interaction between sound waves and the human body are particularly important but difficult to reproduce.
Listeners experience sound in three dimensions: left/right, up/down, and near/far (azimuth, elevation and range). Typical two-speaker systems can control only the left/right aspect. Even state-of-the-art "three-dimensional" sound systems generally can only locate sounds on a circle around a listener, and not in all three dimensions.
Among the challenges to creating true three-dimensional sound fields is that each person's spatial sound cues are strongly influenced by individual physical factors such as the shape and position of their ears. These factors -- which are captured by so-called Head-Related Transfer Functions (HRTFs) -- vary greatly from person to person. To mass-produce digital systems that accurately reproduce three-dimen
'"/>
Contact: Peter West
pwest@nsf.gov
703-292-8070
National Science Foundation
17-Dec-2001