PURPOSE: To easily and ecomonically confirm the storing and reproducing function of the voice signals with the stable precision by adding and identifying a transmitting/receiving function of the PB signals and a loop back function among the voice signal paths.

CONSTITUTION: When the automatic test of a voice processor is selected, a service control part 5 starts a time division switch 4 to secure the connection of a vice data signal path b1 between a PB signal transmitting part 8 and a maintenance test control part 3 and transmits the PB signals. These signals PB are folded back to a voice signal path b2 at the part 3, coded at a voice signal processing part 6, and stored in a memory at a voice storage processing part 7. Then the part 5 starts the switch 4 to secure the connection of a voice data signal path b4 between a PB signal receiving part 9 and the part 3 and takes the voice data on the PB signal out of the memory. These voice data are decoded by the part 6 and transmitted. Then these PB signals are folded back to the path b4 at the part 3 and identified by a PB signal receiving part 9.