| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an "audio system" capable of sufficiently exhibiting the surround effect even if an input signal level is low, and performing a processing so that the surround is not affected by a difference in the input signal level when producing the surround effect under adaptive control with an adaptive algorithm. <P>SOLUTION: In the audio system including a surround production unit which operates a differential between a signal resulting from processing one input signal by an adaptive control unit including an adaptive algorithm and the other input signal, in input signals of respective channels, updates an adaptive filter coefficient in accordance with the differential, the one input signal and a step size parameter using the adaptive control unit and outputs the differential as right and left surround signals, a dynamic range compression unit is provided at a signal input side of the surround production unit and control is performed to enlarge the compression as the level of the input signal is low. Furthermore, control is also performed to increase an input gain, etc., when the input level is low. <P>COPYRIGHT: (C)2008,JPO&INPIT |
