PURPOSE: To surely understand a message, by changing the speed of utterance of same messages repeatedly in response to the instruction of repetition by the operator.

CONSTITUTION: At the 1st utterance of a message, a control section 11 transmits a reset pulse signal to a reset signal line 14 and resets a counter 4, and a gate pulse signal is outputted to a gate signal line 15 to input the output of the counter 4 to an audio output section 10. The section 10 can change over the message utterance speed in 16 stages, and when the output value of the counter 4 to be inputted is 016, the utterance speed is the fastest and in case of F16, the slowest. If the 1st message is not got, when a repetition key 2 is depressed, one pulse signal is given to a repetition instruction line 3, then the counter 4 is decremented by one and the section 10 outputs the same message again in the slower utterance speed than the 1st utterance.