Patent ID: 7382885

Claim:
A multi-channel audio reproduction apparatus for loudspeaker reproduction using a virtual sound image whose positions can be adjusted with respect to an input monaural audio signal, the multi-channel audio reproduction apparatus comprising: a controller for generating weighted values and values of phase delay for adjusting a position at which a second virtual sound image will be formed based on a predetermined position A at which a first virtual sound image A will be formed and a predetermined position B at which another first virtual sound image B will be formed with respect to the input monaural audio signal for loudspeaker reproduction, wherein the value of the phase delay for the virtual sound image position A comprises a measure of a distance between a virtual sound image position A and a virtual sound image position A′ for forming the first virtual sound image A and the value of phase delay for the virtual sound image position B comprises a measure of distance between the virtual sound image position B and virtual sound image position B′ for forming the first virtual sound image B; an output position adjustor for dividing the input monaural audio signal into two signals and applying the weighted values and the values of phase delay to corresponding signals of the divided monaural audio signal to adjust the position at which the second virtual sound image will be formed to a desired position between positions A and B; a virtual sound image forming unit for loudspeakers comprising an A transfer function processor for multiplying the monaural audio signal, obtained by the application of the weighted value and the value of phase delay for the position A to one of the divided monaural audio signals, by transfer functions corresponding to the left and the right ear of a listener for forming the first virtual sound image at the predetermined position A, and a B transfer function processor for multiplying the monaural audio signal, obtained by the application of the weighted value and the value of phase delay for the position B to the other divided monaural audio signal, by transfer functions corresponding to the left and the right ear of the listener for forming the first virtual sound image at the predetermined position B; and an adder for summing up the audio signals obtained by the multiplications of the transfer functions for forming the first virtual sound images at the positions A and B corresponding to the right ear of the listener and summing up the audio signals obtained by the multiplications of the transfer functions for forming the first virtual sound images at the positions A and B corresponding to the left ear of the listener to generate left and right signals for loudspeakers for forming the second virtual sound image at the desired position between positions A and B.