A baby monitor, also known as a baby alarm, is a radio system used to remotely listen to sounds made by an infant. The transmitter, equipped with a microphone, is placed near to the child and the receiver equipped with a speaker, is carried by, or near to, the person caring for the infant. Some baby monitors provide two-way communication which allows the caregiver to speak back to the baby (parent talk-back). Some allow music to be played to the child.
One of the primary uses of baby monitors allows attendants to hear when an infant wakes, while out of immediate hearing distance of the infant. Although commonly used, there is no evidence that these monitors prevent SIDS, and many doctors believe they provide a false sense of security.