Abstract: A method of synthesizing an audio signal having left and right channels corresponding to an extended virtual sound source at a given apparent location in space relative to a preferred position of a listener in use is described. The information in the channels includes cues for perception of the direction of said virtual sound source from the preferred position. The extended source comprises a plurality of point virtual sources, the sound from each point source being spatially related to the sound from the other point sources, such that sound appears to be emnitted from an extended region of space. If the signal from two sound sources is the same, they are modified to be sufficiently different from one another to be separately distinguishable by a listener when they are disposed symmetrically on either side of the listener. This modification can be accomplished by filtering the two point sources using different comb filters.

Abstract: Techniques are provided to use near-field speakers to add depth information that may be missing, incomplete, or imperceptible in far-field sound waves from far-field speakers, and to remove the multi-channel cross talk and reflected sound waves that otherwise may be inherent in a listening space with the far-field speakers alone. In some possible embodiments, a calibration tone may be monitored at each of a listener's ears. The calibration tone may be emitted by two or more far-field speakers. One or more audio portions from two or more near-field speakers may be outputted based on results of monitoring the calibration tone.

Abstract: Techniques are provided to use near-field speakers to add depth information that may be missing, incomplete, or imperceptible in far-field sound waves from far-field speakers, and to remove the multi-channel cross talk and reflected sound waves that otherwise may be inherent in a listening space with the far-field speakers alone. In some possible embodiments, a calibration tone may be monitored at each of a listener's ears. The calibration tone may be emitted by two or more far-field speakers. One or more audio portions from two or more near-field speakers may be outputted based on results of monitoring the calibration tone.