PURPOSE: To attain reply without use of a telephone set.

CONSTITUTION: A telephone exchange A selects and forms a channel between an external line and an extension L2 or between extensions L2 and a telephone set C is used to make external line talking and extension talking. In the case of simultaneous talking, a cross point switch is used to form a channel between the caller extension L2 and the called control line L3 A speech circuit 29 is provided to the channel to attain 2-way talking between the extension L2 and the control line L3. A speaker SP of the telephone receptacle B is used for a microphone to attain a reply with respect to a voice contact.