PURPOSE: To elevate efficiency for operating a key, by generating a voice corresponding to the depressed key from the speaker.

CONSTITUTION: When the key of the keyboard 1 has been depressed, a signal is sent to the encoder 2, in which it is converted to a binary or BCD code. The signal from the encoder 2 is output to the information processing unit 5, executes the prescribed information processing, and also it is sent to the voice signal generator 3. The voice signals corresponding to plural keys 11, 12... are stored in the drum, etc., and the generator 3 generates the voice signal concerned corresponding to the key which has been depressed. This voice signal is input to the speaker 4, and a voice is output. Accordingly, whether the key has been operated properly or not can be confirmed by the voice, and therefore, not only the efficiency for operating the key is elevated but also fatigue of an operator is reduced.