To make the device be suitable for the use of many unspecified persons without increasing the size of a storage medium.

By pressing down a voice registration key on a control section (S1), an ID number is inputted (S2). Then, while pressing down a desired key, voice data corresponding to the key are inputted (S3 to S4). Then, confirmation is made to check the fact that the key input and the voice data input are performed simultaneously and the device is set to a voice data registration mode (S5). Then, the degree of similarity is computed by conducting a pattern matching of inputted voice data and the voice data registered in a directionary (S6). If there is no similar command, the inputted voice data are registered in the direcitonary (S8). If there exists a similar command, a prescribed message is displayed on the control section (S9).