Some swear by their bedroom fan. Others have tried every sleep sound app and still wake at 3 a.m. when a car door slams.

Here is the short answer. White noise can help you sleep, mostly when noise is the thing waking you up. It is a tool for a noisy bedroom, not a cure for poor sleep. And how you use it matters as much as whether you use it.

What White Noise Actually Is

White noise is a steady “shhh” sound that spreads its energy evenly across all the pitches your ear can hear. Think of TV static or a fan on high.

You will also hear about other “colors” of noise:

• Pink noise is deeper and softer, like steady rain.
• Brown noise is deeper still, like a low rumble or a distant waterfall.

Researchers group all of these under the label broadband noise, and most studies treat them as one family. In this article, I use “white noise” to mean the whole family unless I say otherwise.

Why Your Brain Wakes Up to Noise

Your ears never fully switch off at night. Your brain keeps listening for danger while you sleep.

What wakes you is usually not the noise level itself. It is the change. A quiet room followed by a barking dog, a passing truck, or a partner’s cough creates a sharp jump in sound. Your brain notices that jump and pulls you into lighter sleep or full wakefulness. Often you do not even remember waking. You just feel unrefreshed in the morning.

White noise works by raising the background floor. When the room already has a steady hum, a sudden sound stands out less. The jump is smaller, so your brain is less likely to react. Sleep doctors call this masking.

There is a second, softer benefit. A consistent sound can become part of your bedtime routine. Over time, your brain links it with sleep, much like dimming the lights or brushing your teeth.

What the Recent Research Shows

For this article, I looked only at research from the last five years and gave the most weight to randomized controlled trials, the strongest type of study. Here is what holds up.

In Hospitals, the Evidence Is Fairly Good

Hospitals are loud and unpredictable. Alarms, footsteps, and conversations continue all night. This is where white noise has its strongest support.

A 2025 meta-analysis combined 12 randomized trials with about 1,300 people. White noise improved sleep quality scores in adults and older adults, both in intensive care units and on regular hospital wards. The authors noted that results varied between groups and that the quality of the individual studies was mixed.

A separate 2025 review by Mayo Clinic researchers looked at seven randomized trials in hospitalized adults. White noise and similar masking sounds improved sleep efficiency, meaning patients spent more of their time in bed actually asleep. Patients tolerated it well, with no major side effects reported.

For premature babies in the neonatal ICU, a 2024 meta-analysis of eight randomized trials found that carefully controlled white noise lowered pain scores, steadied heart rate and breathing, and supported weight gain. Keep in mind that this was in a hospital, with volume managed by trained staff. That is very different from a sound machine sitting on a crib rail at home.

At Home, the Picture Is Less Clear

Most of us do not sleep in an ICU. For everyday bedrooms, the evidence is thinner.

A 2022 systematic review in the Journal of Clinical Sleep Medicine found that just over half of the studies on sound and sleep reported a benefit. Most of those studies were small and of low quality.

A large 2026 trial published in the journal Sleep randomized 495 working adults who reported poor sleep. One group used app-based sleep sounds for four weeks, including nature sounds and colored noise. They did no better than a control group using a similar app without sleep content. Sound alone did not fix their sleep problems.

A New Study Raises a Real Concern

In early 2026, researchers at the University of Pennsylvania published a carefully controlled sleep lab study. Twenty-five healthy adults spent seven nights in the lab, exposed in random order to silence, traffic and aircraft noise, pink noise, a mix of both, and outside noise while wearing foam earplugs.

The results surprised many people in my field:

• Outside noise cut deep sleep by about 23 minutes.
• Pink noise alone, at about the volume of moderate rain, cut REM sleep by about 19 minutes. REM is the dreaming stage linked to memory, mood, and brain development.
• Pink noise played over traffic noise did not protect sleep. Deep sleep and REM sleep both dropped, and people spent about 15 more minutes awake.
• Foam earplugs largely protected deep sleep from the outside noise.

This was a small study of young, healthy adults over one week. People who already used sleep sounds were excluded, so we do not know whether long-term users adapt. Still, the design was strong and the findings deserve attention. An editorial in the same journal issue urged caution, especially for children, who spend far more of their sleep in REM than adults do.

Why Sleep Doctors Still Recommend White Noise

In the right situation, the benefit is real, and the risk is low when you use it well.

White noise makes the most sense if you:

• Live near a busy road, airport, rail line, or noisy neighbors.
• Work nights and sleep during the day while the world around you is awake.
• Share a room with someone whose movements or sounds wake you.
• Are sleeping in a hospital, hotel, or other unfamiliar place.
• Find that total silence makes you more alert to every small sound.

It makes less sense if your bedroom is already quiet. In that case, adding sound is unlikely to help and may cost you some REM sleep.

Babies and Children Need Extra Care

Many parents use sound machines, and I understand why. A tired baby means a tired family.

The concern is volume and time. A 2024 scoping review in Sleep Medicine found that some white noise machines can exceed 91 decibels at full volume. That is louder than what is considered safe for an adult worker over a two-hour shift. Animal studies suggest that long exposure to moderate noise may affect hearing and brain development. The same review noted that low-volume sound during sleep may still be helpful.

If you use a sound machine for your child:

• Place it across the room, at least 6 to 7 feet from the crib. Never put it on the crib rail.
• Keep the volume low. Think soft shower, not loud fan.
• Use a timer so it turns off after your child falls asleep.
• Do not run it all day as background noise.

How to Use White Noise the Right Way

If noise is truly what disturbs your sleep,

1. Try earplugs first. For outside noise like traffic, the best recent evidence favors foam earplugs. They are inexpensive, and they block sound instead of adding more. Roll them tightly and let them expand fully in the ear canal.
2. Keep it quiet. Use the lowest volume that covers the disruptive sound. Aim for under 50 decibels at your pillow, about the level of soft rain or a quiet conversation. The free NIOSH Sound Level Meter app can measure this for you.
3. Keep it at a distance. Place the machine across the room, not next to your head. Avoid sleeping with earbuds playing sound all night.
4. Use a timer. Much of your REM sleep happens in the second half of the night. A timer that shuts the sound off one to two hours after bedtime helps you fall asleep while protecting later sleep. If early morning noise is your main problem, a longer timer may suit you better.
5. Pick a steady sound. Constant sounds work better than music, stories, or nature tracks with bird calls and thunder. Changing sounds can trigger the very wake-ups you are trying to prevent.
6. Fix the source when you can. Heavy curtains, a door draft stopper, sealed window gaps, and moving your bed away from a street-facing wall all reduce noise without adding more.

When White Noise Is Not the Answer

If you still struggle to fall asleep, stay asleep, or wake up refreshed, noise may not be the real problem.

See a sleep doctor if:

• You lie awake for 30 minutes or more on three or more nights a week, for three months or longer. This may be insomnia, and cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment.
• You snore loudly, gasp or choke at night, or feel sleepy during the day. These can be signs of sleep apnea.
• You use white noise to drown out a bed partner’s loud snoring. Their snoring may need an evaluation too.
• You notice ringing in your ears or new trouble hearing.

Bottom Line

White noise is a reasonable tool for a noisy bedroom. It is not a sleep treatment on its own.

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Disclaimer: This article is for general education only and is not a substitute for personal medical advice. If you have ongoing sleep problems, hearing concerns, or questions about your child’s sleep, talk with your doctor or a board-certified sleep medicine physician.

References

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