Abstract #21089, Date "Wednesday, Feb 7 2001 1:00PM - 12:00PM " Session AA13 Sound Localization II - Psychophysics and Perceptual Effects

Effect of listener location on localization cues and localization performance in a reverberant room

Norbert KOPCO , Tara Brown , Barbara G. SHINN-CUNNINGHAM

"To a first-order approximation, the amount of reverberation reaching a listener depends on the properties of the room and is independent of the position of sound source or listener within the room. Nonetheless, there are important changes in the pattern and level of reverberation reaching a listener with changes in listener or source position, especially when sources are near the listener's head. In this study, the transfer functions from a nearby source (within one meter of the head) to the ears of a listener were measured in the same reverberant room in which human localization performance was measured. Transfer functions for sound sources located at different positions in the right front quadrant (varying in both distance and direction) were measured at the ears of a manikin head for different positions of the manikin in the room. Analysis shows that listener and source locations influence the binaural and monaural properties of the reverberation reaching a listener in a room. For instance, for nearby sources in some directions, the absolute level of reverberation reaching the ear tends to increase with decreasing distance (see figure). Localization performance for sources varying in distance and direction in the right front quadrant was also measured. Localization performance was analyzed in terms of the directional and distance accuracy and bias. Comparison of the acoustic transfer functions and behavioral results explores the degree to which localization accuracy and response bias can be explained by properties of the reverberation reaching the listener. [Work supported in part by AFOSR Grant No. F49620-98-1-0108.] "