Binaural speech intelligibility as a function of speaker angle and interaural cross-correlation of disturbing noise and reverberation.

Abstract

Subjective intelligibility tests were carried out that demonstrate that binaural speech intelligibility under adverse acoustic conditions, such as noise and reverberation, improves when listening at an angle, and also depends on the interaural cross-correlation of the disturbance. Speech material was binaurally recorded in an anechoic chamber using an acoustic manikin, from a loudspeaker at different azimuth angles from −60 deg (left) to +60 deg (right) in 15-deg steps. The binaural speech material was contaminated with interaurally correlated and uncorrelated noise and reverberation, and was presented to listeners through headphones. Results indicate advantages of binaural speech intelligibility under adverse acoustic conditions when listening at an angle, relative to listening at 0 deg. Additionally, speech intelligibility improves when the disturbing reverberation has high interaural cross-correlation; while on the other hand, speech intelligibility improves when the disturbing noise has low interaural cross-correlation.