Attentional tracking in real-room reverberation.

Abstract

A listener can attend to one talker in a mixture of sound sources, and a difference in bearing between “target” and interfering sources is thought to aid this “tracking.” Interaural cues are degraded by reverberation however, raising the question of what cues are actually used to track sources in rooms? Listeners can also use differences in voice characteristics, so this study asks how well cues arising from location compete with talker differences when tracking messages in real-room reverberation. Real room measurements of binaural room impulse responses (BRIRs) were used to spatialize the stimuli and listeners decided which of two simultaneous target words belonged in a target phrase played simultaneously with a “distracter” phrase. Location differences were in competition with talker differences so that listeners’ responses indicated which cue-type they were tracking. Further experiments used processed BRIRs to eliminate temporal cues. Location was dominant over talker difference in dichotic but not diotic conditions, and results with processed BRIRs indicated that this “binaural advantage” is almost entirely due to ILD. Furthermore, an analysis of spectral distances between BRIR channels revealed that the probability of location difference overriding talker difference correlates with the distance between ILD patterns but not with monaural spectral distances.