Auditory Distance Perception of Speech in the Presence of Noise

This study examines the effects of background noise, actual source distance, and room reverberation on the perceived distance of a single phrase of recorded speech reproduced at a naturalistic sound pressure level. A simple rectangular room was used for stimulus generation, wherein binaural recordings were made with source-receiver distances between 0.9 m and 5.1 m, reverberation times between 0.7 s and 5.7 s, and effective continuous background noise levels between 30 dBA and 66 dBA. Subjects, wearing headphones, judged the distance of the speech source in these recordings. The three independent variables of physical distance, reverberation time and background noise level each had a positive effect on perceived distance. Previous studies, using noise targets, have found the presence of background noise to reduce perceived distance. One possible explanation for this discrepancy is that auditory distance cues for speech are weighted differently to those of arbitrary signals, such as noise.