Patent ID: 8526637

Claim:
A volume control apparatus that is connectable to a controller and controls a volume value of a sound signal based on an instruction from the controller, comprising: a receiving section for, when a controller-side volume setting value settable in the controller is changed by a user's operation, receiving the changed controller-side volume setting value from the controller; a first difference value calculating section for calculating DMC_VolDif=Current_DMCvolVal−Prev_DMCVolVal; a second difference value calculating section for calculating DMR_VolCapacity=F(DMRVolMax)−F(DMRVol); and an increase value calculating section for calculating an increase value of the volume value as DMR_VolCapacity×(DMC_VolDif/100), wherein DMC_VolDif is a first difference value, Current_DMCvolVal is the changed controller-side volume setting value, Prev_DMCVolVal is the controller-side volume setting value before change, DMR_VolCapacity is a second difference value, F(DMRVolMax) is a maximum volume value controllable by the controller, and F(DMRVol) is a current volume value.