PURPOSE: To eliminate low band noise such as rumble noise, etc. without deteriorating a low band characteristic, by extracting a high band component and a low band component from the input signal of each right and left channel, mixing the right and left low band components, adding them to each high band component, and outputting them.

CONSTITUTION: High band components of right and left channel CH signals from a stereo record inputted from terminals 10, 12 are extracted by HPFs 14, 20, respectively, and the low band components are extracted by LPFs 16, 18, respectively. Cut-off frequencies of each HPF14, 20 and LPF16, 18 are set to the same. The low band components extracted by the LPFs 16, 18 are added and mixed by an adder 22, and its output is added to the high band components from the HPFs 14, 20 by adders 24, 26, respectively, and outputted to each CH of the right and left. The noise such as rumble, etc. in the low band components from the LPFs 16, 18 has no correlativity in phase, therefore, it is averaged by the adder 22 and suppressed, and since a normal signal has a correlativity, it is increased by the adder 22, added to the high band component of each CH of the right and left, and outputted, therefore, the low band characteristic is not deteriorated.