PURPOSE: To obtain a simultaneous calling and reply system capable of talking with a call device without requiring any switch operation and bypassing of voice by connecting each terminal equipment in parallel with a signal path extended from a voice switch.

CONSTITUTION: The voice switch 26 compares a level of a voice signal sent through signal lines 27A, 27B and a level of a voice signal sent through signal lines 28A, 28B. When the level of the voice signal sent from the signal lines 27A, 27b is larger, the signal is sent to a signal path 29, and when the level of the voice signal sent through the signal lines 28A, 28B is larger, the signal is sent to a call device 21. After the call device 21 makes a call, all microphones 301∼303 of terminal equipments 221∼223 are activated to pick up the sound, but the sound is not returned to speakers 311∼313 via a voice switch 26 and only the voice of the call device 21 is listened to from the speakers 311∼313.