Home intercom systems serve two purposes – they work as security systems for monitoring particular areas or rooms in the house as well as communication devices for speaking to anyone in another room or floor. A typical intercom consists of a fixed microphone and a speaker unit that can be installed anywhere in the house.
A home intercom system can have one or more master stations that control the system and initiate the calls to any of the speaker units or sub-stations. The sub-stations (or slave units) can initiate calls to the master station but not to other sub-stations. Many home intercom systems also have door stations which are similar to sub-stations, capable only of initiating calls to the master station. They are used for screening or monitoring those who go inside the house. Since they are usually connected to the door buzzer outside the house, they are weatherproof.
A Voice-only home intercom system is only capable of monitoring sounds coming from the room. It is used to communicate using only the voice. It usually consists of a button for speaking to the master station and a buzzer for paging.
A Video home intercom system allows the user to talk and view the person on the speaker unit through live video. It allows visual monitoring (just like a security camera). It is ideal for monitoring babies or small children in another room.