| 摘要 |
PROBLEM TO BE SOLVED: To improve a response characteristics when a level of an input audio signal changes from a large one to a small one. SOLUTION: The processing unit is provided with a gain control amplifier 52 that receives an input audio signal and a level detection circuit 61 that detects a level of the input audio signal, and also a control signal generating circuit 63 that generates a control signal of a gain of the gain control amplifier 52 according to a detection signal of the level detection circuit 61. The gain control amplifier 52 has an input output characteristics where the received input audio signal is compressed to a level and the compressed signal is outputted. A response time of the gain control amplifier 52 whose gain changes from a small one to a large on by decreasing a large level of the input audio signal into a smaller level is changed depending on setting contents of level compression and a history of a level change in the input audio signal. |
