When a user gives a parameter storage instruction via a remote controller, current settings of parameters in an input switching circuit, surround circuit, graphic equalizer and electronic volume are stored into a non-volatile RAM. Then, once the user gives a reproduction instruction via the remote controller, the stored settings of the parameters are read out from the non-volatile RAM and set to the input switching circuit, surround circuit, graphic equalizer and electronic volume. Once the user selects a desired one of customizing buttons that are provided on the remote controller belonging to an audio apparatus connected with a personal computer and selects functions to be allocated to the selected customizing button, the personal computer creates setting information in accordance with the user's selections, and transmits the thus-created setting information to the audio apparatus. In turn, the audio apparatus stores the allocated functions of the customizing button on the basis of the setting information.