PURPOSE: To automate a fire fighting by providing a public line interface function controlled by a voice synthesis function interfacing a fire fighting command telephone line to the synthesizer.

CONSTITUTION: When the information required for voice command from a fire fighting command computer 6 is sent by a host interface function 1, a voice synthesis function 3 edits the voice information to control a command line interface function 2 to the command line and to control a public circuit interface function 4 to a fire fighting command telephone set thereby outputting a voice command. Moreover, the control of an output of the command line interface function 2 only and the control of an output of the command line interface function 4 only are attained under the control of the voice synthesis function 3 by adding information to designate the output to the command line only or the output to the fire fighting command telephone line only with respect to the information sent from the fire fighting command computer 6. Thus, the fire fighting command is automated.