Audio apparatus and its reproduction program

Abstract

An input signal X of a first channel is divided by a multi-stage delay processor Z<-1> and each of the outputs is superimposed by a predetermined coefficient by a coefficient processor W0,W1,..., Wk. The results are added by an adder Sigma, thereby providing a non-correlating filter for extracting a signal component from the input signal X of the first channel having a high correlation with an input signal Y of a second channel. There is provided a coefficient updating processor (5) for successively changing the feature of the non-correlating filter according to an error signal e obtained from the output signal RES and the input signal Y from the second channel, and the input signal X of the first channel. A surround signal is obtained from a difference between the output RES from the non-correlating filter and the input signal Y of the second channel. Thus, upon reproduction of a two-channel stereo signal, it is possible to generate a surround signal not giving uncomfortable feeling to a listener.

Description

technical field [0001] The present invention relates to an audio device that generates a multi-channel audio signal from a two-channel stereo audio signal and a program for reproducing the same. Background technique [0002] There has been a demand for generating multi-channel audio signals from two-channel stereo audio signals for many years, and many audio devices have this function, but it often gives people a sense of inversion and incongruity during reproduction. [0003] To generate a multi-channel audio signal from an existing two-channel signal, that is, to generate a signal that is reproduced from the side to the back of the listener called a surround signal, or to generate a signal that is expected to be positioned on the side or back of the listener The OSL signal and OSR signal are usually as figure 1 As shown in the following equation (1), the difference between the input stereo audio signals INL and INR is calculated and reproduced. [0004] OSL=INL-INR [0...

AI Technical Summary

Problems solved by technology

However, for the signals obtained by formula (1), that is, signals with the same amplitude but opposite phases, the sense of inversion and incongruity has not been eliminated due to the implementation of the above-mentioned de-correlation processing

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