Baby monitors, which are commonly known as baby alarms, are basically radio systems used to listen to the sounds made by babies from where they are. The device has a transmitter unit, set with a microphone which is positioned near to the child. It transmits the sounds with the use... Baby monitors, which are commonly known as baby alarms, are basically radio systems used to listen to the sounds made by babies from where they are. The device has a transmitter unit, set with a microphone which is positioned near to the child. It transmits the sounds with the use...