Adaptive surround technology for stereo music signals

Abstract

Computation of the left and right channel instantaneous difference (xL−xR) is mostly used to obtain the signals for surround sound. This signal is usually referred as the antiphase components. However, there are many problems to using the antiphase components in terms of its applicability in practice as well as the sound quality. For instance, when signals xL and xR are equal, or almost equal, this variation, that is to say, the correlation coefficient value, is high; there is no way to determine the direction vector uniquely, therefore an ambiguity may appear. Instead of the antiphase component’s computation, a new method is proposed by using an adaptive signal processing technique. In this paper, it is revealed that natural surround sound signals having no antiphase and uncomfortable feeling are adaptively generated by the proposed method. The other advantages from a signal processing point of view are also discussed. Finally, subjective evaluations on sound quality of a surround sound system are carried out.