PURPOSE: To discriminate an operated switch with a small number of parts by providing a mode selecting means which selects the sound emission mode for operation information input, an operation information input means, and a sound emission control means which generates musical sounds corresponding to operation information in accordance with the mode.

CONSTITUTION: An operation information input part 20 is the operation information input means consisting of various switches provided on a panel and their scan circuit. A mode selecting part 30 selects not only the normal state but also modes such as the check mode (used for function check in a factory) and the mute mode in accordance with information from the operation information input part 20. A sound emission control part 40 generates musical sounds corresponding to operation information in accordance with the mode selected by the mode selecting means 30. Consequently, the operated switch is confirmed without providing a display device of LED for each switch, and the constitution of the device is simplified, and the operability is improved.