An audio signal processing apparatus has a plurality of channels for controlling a plurality of audio signals. In the apparatus, a volume setting unit sets volume parameters of the plurality of channels. A group generation unit determines a plurality of groups each including one or more channels among the plurality of channels. An attenuation setting unit sets an attenuation amount for each group. An on/off setting unit sets each group to either an on-state or an off-state. A plurality of volume controllers control the plurality of channels, a volume controller of each channel, which belongs to a group in the off-state, controlling a level of the channel and a volume controller of each channel, which belongs to a group in the on-state, generating a volume value by attenuating the volume parameter set to the channel by the attenuation amount set to the group and controlling a level of the channel.