Sleep Science
White Noise, Music & Sound: What Really Helps Babies Sleep
Parents have tried everything—white noise machines, lullabies, shushing apps. What does the research say about sound and infant sleep?
Sound and baby sleep: myth or magic?
For centuries, parents have used sound to soothe babies—think lullabies, gentle humming, or even a vacuum in the background. Modern parents have more options: white noise machines, Spotify playlists, or sleep apps. But what actually works? Here’s a research-backed breakdown of sound, sleep, and how to use it safely.
Why sound impacts infant sleep
- Womb memory: Babies spend months surrounded by rhythmic whooshing of blood flow (~70–90 decibels). White noise mimics this environment.
- Sleep associations: Sound cues the brain to shift toward rest. Over time, babies connect certain sounds with bedtime.
- Masking effect: Continuous background noise covers sudden environmental sounds (door slam, dog bark), reducing night wakings.
- Emotional regulation: Music and humming lower stress hormones, which can make it easier to settle.
White noise
Steady, static-like noise (fans, machines, apps). Most studied for infant sleep. Effective for newborns and infants up to ~12 months. Should be continuous, not too loud (safe range: 50–60 dB, about a running shower heard from the bathroom).
Pink/brown noise
Lower-pitched, softer than white noise. Early research suggests it may be gentler on the brain and improve deep sleep in adults—parents report babies also respond well.
Music & lullabies
Studies show lullabies decrease infant distress and stabilize heart rates. Familiar, repetitive songs (often with parent voice) are the most soothing. Classical or acoustic tracks are commonly used, but consistency matters more than genre.
Parental voice
Your voice is the most familiar sound. Soft singing, humming, or shushing may calm babies faster than mechanical sound. One study found parental singing reduced crying and extended sleep bouts in infants under 6 months.
Best practices for sound and baby sleep
- Volume: Keep under 50–60 dB (about conversation level). Avoid placing machines directly next to the crib.
- Consistency: Pick one approach and use it regularly. Babies learn faster when bedtime cues are predictable.
- Duration: Continuous sound through the night is most effective; timers that shut off can cause wake-ups.
- Safe placement: Place machines at least 7 feet from crib, never inside.
- Parent voice bonus: Layer humming or singing with background noise during tough nights.
Do sound cues work during sleep regressions?
Yes—sound can help, but it’s not a cure-all. During regressions (4, 8–10, 12 months), babies may wake frequently due to milestones, not noise. White noise and lullabies can still shorten wake times and ease resettling, but routines and patience remain essential.
Sound across cultures
Lullabies are universal—every culture has them. Some communities use drums or heartbeat-like rhythms. Others rely on chanting or rocking songs. The method differs, but the principle is the same: predictable rhythm plus parent connection helps babies rest.
When sound doesn’t work
- Try a different frequency: some babies prefer pink noise over white.
- If baby startles awake when sound stops, run it all night.
- Experiment with your own voice—babies often prefer it to machines.
- If overstimulation occurs, try silence + swaddle + dark room.
FAQs About Sound & Baby Sleep
Is white noise safe for newborns?
Yes, when kept under 50–60 dB and placed several feet from the crib. Avoid direct exposure.
Can babies become dependent on white noise?
Yes—sound becomes a sleep association. This isn’t harmful, but parents should be aware they may need sound at naps and bedtime.
What type of music works best?
Simple, repetitive, and soothing. Parent voice or lullabies usually outperform playlists.
Is white noise better than lullabies?
Not necessarily. White noise helps mask environmental disruptions, while lullabies comfort emotionally. Many parents use both.
When should I stop using sound?
There’s no strict cutoff. Many families continue white noise or soft music into toddler years. The AAP notes no harm if used safely.
Key insights
Sound can be a powerful tool for baby sleep when used safely: white noise to mimic the womb, lullabies for comfort, and parent voice as the ultimate cue. Keep volume safe, use consistently, and remember—sound supports sleep, but routines and safe sleep practices matter most.
This guide is educational only and not medical advice. Always follow safe sleep guidelines and consult your pediatrician for individual recommendations.