| 摘要 |
PROBLEM TO BE SOLVED: To decrease waveform distortion in the case of controlling a signal, which exceeds a saturation level, into proper signal level, to suppress the increase of a white noise at the time of silence, and to simplify circuit scale and arithmetic processing concerning a signal level controller for controlling the signal level of audio or the like. SOLUTION: The gain of a gain storage part 1-9 is multiplied to an input signal in by a gain multiplying part 1-1 and outputted as an output signal out. When it is detected by a gain monitoring part 1-2, the gain exceeds a prescribed threshold and when it is detected by an output level saturation monitoring part 1-3, an output signal level exceeds a prescribed saturation level, a coefficient >1 selected by a coefficient selecting part 1-7 is multiplied to the gain, and the gain is gradually decreased. Besides, in the other case, a coefficient exceeding '1' is multiplied to the gain and the gain is gradually increased. Since the gain is smoothly transited and does not exceed the prescribed threshold, the waveform distortion is decreased and the increase of the white noise at the time of silence is suppressed. |
