A baby monitor is a device used to remotely listen the noises made by an infant. A baby monitor is primarily used to keep track of any problem with baby when the infant is asleep in a separate room or while one is away from the baby. A baby monitor is also known as a baby alarm.

A baby monitor technology includes a simplex (unidirectional) radio transmitter and receiver system equipped with a microphone and a receiver equipped with a speaker. The microphone is placed near to the child and the receiver is carried by, or near to, the person caring for infant.

The frequency used by the devices usually lies in the range of 49