Douglas S. Brungart
AL/CFBE, 2800 Q Street, WPAFB, OH 45433-7901
AL/CFBA, WPAFB, OH 45433-7901
Although reverberation is known to play an important role in the perception of distance, it is not possible to isolate the effects of early and late reflections in a real environment. A virtual audio display, however, can be used to examine the effects of early and late reflections on distance identification. In this experiment, a virtual audio display simulates distant sound sources under 4 conditions: Without reflections, with an early reflection (floor reflection) only, with late reflections (reverberation) only, and with both early and late reflections. In each trial, the subjects identify the distance of the simulated sound source from one of 5 possible distances: 2, 4, 8, 16, and 32 ft. Numbered targets are placed at the locations of the simulated sound sources, allowing the subjects to visualize the distances involved. White noise and speech are used as stimuli in the experiment, and their amplitudes are randomized over 24 dB to prevent identification based on intensity alone. The results will be analyzed to measure the percentage of correct responses at each distance and the information transfer in each of the 4 conditions.