| 摘要 |
PURPOSE:To correct a hearing characteristic in the case of low volume and to suppress excess volume by controlling the amplification factor of a low frequency range corresponding to the level of an input signal while passing only the low frequency range through a signal compressing circuit. CONSTITUTION:The input signal of an input terminal 1 is divided into a high- pass filter 3 and a low-pass filter 4, and the output of the filter 4 is passed through a signal compressing circuit 5 and added with the output of the high- pass filter 3 by an adder 6. In this case, in the signal compressing circuit 5, the lower the input level is than a reference level, the more the amplification factor is increased, and the more the level is than the reference level, the more an attenuating amount is increased. Thus, the hearing feeling when the low frequency signal at a low level is corrected, and the distorting feeling can be suppressed when the signal is at a too much higher level. |
