Surround signal processing apparatus

Abstract

A surround signal processing apparatus, by which an inputted rear surround signal can be reproduced, together with two-channel front stereophonic signals, through a pair of speakers arranged in front of and in substantially right-and-left symmetry about a listener, in such a way that two sound images of the reproduced rear surround signal can be localized at two predetermined positions relative to the listener. The inputted rear surround signal is processed by a filter. The signal processed by the filter is added to one of the stereophonic signals, and then outputted to one of the pair of speakers. Further, an inversion signal of the filter-processed signal is added to the other of the stereophonic signals, and then outputted to the other of the speakers. Here, the transfer characteristics of the filter are determined as follows: (F-K)/(S-A), where S denotes transfer characteristics between one of the speakers and one of the listener's ears positioned on the same side as the speaker, respectively; A denotes transfer characteristics between one of the speakers and one of the listener's ears positioned on an opposite side to the speaker, respectively; F denotes transfer characteristics between one of the two positions at which two sound images are required to be localized and one of the listener's ears positioned on the same side as the image position, respectively; K denotes transfer characteristics between one of the two positions at which the two sound images are required to be localized and one of the listener's ears positioned on an opposite side to the image position; and / denotes a reverse convolution calculation.