Expansion of listening area with good localization in audio conferencing

Audio conferencing quality can be improved by introducing the localization effect for participants at both sites. This paper proposes a new method which can expand the listening area with good localization for each participant in audio conferencing. The method can suppress interference between sounds radiated to different listening areas by using the localization-in-head and precedence effects and the directivity of a doublet source. The proposed stereo reproduction system employs three pairs of loudspeakers placed on a rectangular table. The effectiveness of the system is confirmed by subjective testing and its performance with various recording methods is also investigated. It can provide good localization not only at the center of the listening area, but also at its sides. In terms of recording method, using a center-placed microphone with two spaced microphones was found to contribute to good localization.