To urge registration of positively recognizable voice and to allow voice to be registered in a language easily recognized in voice by judging similarity between voice and a preregistered name at the time of registration, and warning a user of similar one.

The name of a voice signal inputted from a voice input part 12 and passed via an amplifier part 14 and an analog-to-digital converting part 16 is inputted to a voice recognizing part 18 and recognized, and then registered in a name pattern storage part 22. A signal related to this name is inputted to a control part 20. When a speaker inputs voice again from the voice input part 12 in order to confirm this registration, the control part 20 compares voice recognized in the voice regonizing part 18 with the name preregistered in the name pattern storage part 22, and judges the similarity of both. Upon judging them to be similar on the basis of a specified standard, the control part 20 outputs a control signal to a display part 30 and controls to transmit a specified alarm to a user or to inhibit registration.