Volume control apparatus and volume control program

A volume control apparatus comprises signal processing section for performing digital signal processing and a scaling process on an audio signal outputted from a sound source; level adjusting section for amplifying or attenuating a level of the audio signal outputted from the signal processing section, by an amount of adjustment determined based on an instructed amount of change, and outputting the amplified or attenuated audio signal to an outside; storage section for storing a level value of the audio signal outputted to the outside and the amount of adjustment for the audio signal adjusted by the level adjusting section; detecting section for detecting, when a volume controller is controlled by a user, time required for an amount of operation to reach a predetermined value; first setting section for setting an amount of operational change based on the level value stored in the storage section and the detected time; second setting section for setting an allowable amount of change by which the level adjusting section can make an adjustment by an attenuation process, based on the amount of adjustment stored in the storage section; determining section for determining one of the amount of operational change and the allowable amount of change that has a smaller value to be the instructed amount of change; and instructing section for instructing the level adjusting section to adjust the level of the audio signal based on the determined instructed amount of change.