Over time, babies begin to associate hearing white noise with sleep. It can serve as an effective sleepy cue to tell babies sleep is on the horizon. Some caregivers wait to turn on white noise until they lay their baby down for sleep. Others turn on white noise before beginning their bedtime or naptime routine because it also helps babies to relax. If you decide to play white noise throughout your baby’s sleep routine, be sure to keep it at a low volume while reading or singing to your baby.