An intercom (intercommunication gadget), talkback or door phone is a stand-alone voice communications system for use inside a building or little gathering of structures, working autonomously of the general population phone arrange (Azori 2016).
An intercom system is a two-way correspondence electronic gadget that contains hardware to transmit and accepting sound as well as video transmissions.
- Typical areas of application for the intercom function are door communication systems or telephones.
- It is frequently conceivable to incorporate functions of intercom devices, apartment or house doors, into a telephone system. In such a case, the call members can communicate with visitors at the house door by means of the telephone system utilizing the intercom function.