An intercom also called an intercommunicator, or interphone is a stand-alone voice communications system for use within a building or small collection of buildings that functions independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles. Intercoms can incorporate connections to public address loudspeaker systems, walkie-talkies, telephones, and other intercom systems. Some intercom systems include control of devices such as signal lights and door latches.
Intercoms are used on a wide variety of properties; from houses that only require one connection between a resident and the property’s entrance to multi-unit apartments that require intercom hardware to be installed in every individual apartment.