A baby monitor helps you keep ears or eyes on your child when you're not in the room. However, a baby monitor isn't necessary for all homes. If your infant sleeps in the same room as you, you probably won't need a baby monitor right away. If you have a small home and sleep lightly, you may never need this device. A baby monitor is useful if: You're working on sleep training and want to observe your child while letting your baby cry or play before falling asleep. You want to take care of yard work or spend time outside while your baby is sleeping. You enjoy the reassurance of checking in on your baby without having to go to the room and peek in the door. You want to monitor interactions with older children and the baby while you're not in the room with them.