Sleep notes

Does White Noise Help You Sleep? What the Evidence Really Shows

By ToSleep AI · 2026-10-08

Research reviewed October 8, 2026. Published by the developer of ToSleep AI; not independently clinically reviewed. The cited researchers and institutions are not affiliated with ToSleep and do not endorse it.

The short answer: White noise may help when irregular environmental sounds are keeping you awake because a steady background sound can make sudden changes less noticeable. But the overall evidence is mixed and low quality. It is not a proven treatment for insomnia, and adding sound to an already quiet bedroom may not help.

What is white noise?

White noise is a continuous sound containing energy across a broad range of audible frequencies. In everyday products, “white noise” often becomes a loose label for any steady sound: a fan, rainfall, ventilation, static-like audio, or digitally generated colored noise.

Those sounds are not interchangeable. True white noise has equal energy per frequency; pink and brown noise put relatively more energy into lower frequencies and can sound softer or deeper. Nature recordings also rise and fall in recognizable patterns. A study of one sound cannot automatically prove that every sound app, fan or recording has the same effect.

The proposed sleep benefit is usually sound masking. The steady sound raises the background level, reducing the contrast between the room and an intermittent car horn, closing door or conversation. It does not remove the external noise. It changes how sharply that noise stands out.

Does research show that white noise improves sleep?

Not reliably for everyone. A 2021 systematic review examined 38 studies of continuous white noise or similar broadband sound. The studies differed substantially in the sound used, volume, sleep measurement, control condition and population. Results ranged from improved sleep to disrupted sleep. Using the GRADE framework, the reviewers rated the evidence that continuous noise improves sleep as very low quality. Riedy et al., 2021

A separate 2022 systematic review covered 34 studies and 1,103 participants using white noise, pink noise or mixed audio. Nineteen studies reported a positive sleep finding, but only 6 of the 18 white-noise studies did so. The reviewers concluded that evidence was not strong enough to support auditory stimulation as a general sleep aid. Capezuti et al., 2022

That does not mean white noise never works. It means “white noise helps sleep” is too broad. The more defensible question is: does a particular steady sound help a particular person in a particular noisy setting, at a tolerable level?

When might white noise help?

White noise is most plausible when the problem is a changing sound environment rather than silence itself.

Situation	Why it may help	What remains uncertain
Traffic, neighbors or doors create sudden peaks	Steady sound may reduce the contrast of each peak	Whether sleep improves, and at what level
An unfamiliar hotel or shared home has irregular sounds	A familiar sound may make the environment feel more predictable	Familiarity and masking effects are hard to separate
A quiet room already feels comfortable	There may be little unwanted sound to mask	Added sound could be neutral or disruptive
Persistent insomnia without a noise trigger	White noise does not address the many possible causes	Evidence-based insomnia care may be more appropriate

The World Health Organization’s environmental-noise guidance treats noise as a health issue and includes sleep disturbance among its important outcomes. WHO Environmental Noise Guidelines That supports reducing harmful environmental noise; it does not imply that adding continuous sound is always beneficial.

What did the small positive trials find?

Two often-cited experiments illustrate both the potential and the limits.

In a 2017 randomized crossover experiment, 18 healthy adults spent two laboratory nights. Researchers moved bedtime 90 minutes earlier than usual to create transient difficulty falling asleep. Broadband sound at an average of 46.0 dB was compared with environmental noise averaging 40.1 dB. Median time to stage N2 sleep was shorter with broadband sound, but the experiment was small, short and deliberately created an unusual early bedtime. Messineo et al., 2017

In a 2021 study, ten adults who reported sleep difficulty from high environmental noise used a white-noise device at home for one week between two baseline weeks. Wrist actigraphy estimated less wake after sleep onset, and sleep diaries recorded shorter sleep latency during the intervention. The sample was only ten people, there was no blinded parallel control group, and all participants were selected because noise was already a problem. Ebben et al., 2021

These studies support a narrow hypothesis: masking may help some noise-exposed sleepers. They do not establish that everyone should play white noise all night.

Can white noise make sleep worse?

It can feel irritating, become another source of stimulation or make the bedroom louder than necessary. The 2021 review found studies at both extremes—improvement and disruption—and specifically called for better reporting of sound exposure and possible hearing effects.

Sleep also remains responsive to sound. A continuous track that contains loops, gaps, volume changes, notifications or advertisements is not truly steady. A speaker close to the head may create a different exposure from one across the room, even when the phone volume slider looks identical.

If you repeatedly wake more often, feel less rested or need to increase the volume to tolerate the sound, treat that as evidence to stop the experiment—not as a reason to push through.

How loud should white noise be for sleep?

Research does not establish one safe and effective bedside volume for every device, room and listener. A phone volume percentage is not a decibel measurement. Speaker distance, room surfaces, sound spectrum and device output all change the level reaching the ear.

The National Institute on Deafness and Other Communication Disorders explains that noise-induced hearing loss depends on sound intensity and duration, and that long or repeated exposure to sounds at or above 85 dBA can damage hearing. NIDCD: Noise-Induced Hearing Loss This is a hearing-risk reference, not a recommended sleep setting.

Practical caution is simpler:

Begin at the lowest level that makes an unwanted sound less noticeable.
Place the speaker away from the pillow rather than directly beside the ear.
Prefer a timer or fade-out if masking is mainly needed while settling down.
Avoid headphones or earbuds during sleep, especially when they encourage higher or highly localized exposure.
If a child or infant is involved, do not copy an adult setup; distance, level and clinical context require separate consideration.

Is pink noise better than white noise?

There is no strong general evidence that one color of noise is the best sleep sound. Pink noise has relatively more low-frequency energy than white noise, while brown noise is weighted lower still. People often describe them as softer or deeper, but preference is not proof of improved sleep architecture.

The 2022 review found a larger proportion of positive findings among pink-noise studies than white-noise studies, yet the pink-noise evidence also had substantial risk of bias and included different methods. Comparing percentages across heterogeneous studies is not the same as a head-to-head trial.

Choose based on comfort and the unwanted sound you are trying to mask. Do not assume a color label means a track has been standardized, independently tested or shown to increase deep sleep.

Is white noise a treatment for insomnia?

No. Insomnia is not defined simply by disliking a quiet room. Persistent difficulty falling asleep, staying asleep or returning to sleep can involve timing, learned arousal, health conditions, medication, substances, breathing disorders and other factors.

White noise may modify one environmental input. It does not diagnose the cause, and the research above does not establish it as a replacement for cognitive behavioral therapy for insomnia or clinical assessment. If sleep difficulty is frequent, long-lasting or affecting daytime safety and function, seek evidence-based care rather than continually adding louder sound.

Read our guides to sleep-onset latency and repeated nighttime awakenings for the measurement terms that sleep studies and trackers use.

How can you test white noise without fooling yourself?

A one-night impression is easy to overread. Try a small personal comparison instead:

Define the problem first: traffic peaks, conversations, a partner’s schedule, or simply difficulty settling.
Use the same sound, speaker position, low volume and timer for several nights.
Compare it with several similar nights without the sound.
Record bedtime, estimated time to fall asleep, remembered awakenings and morning comfort.
Note obvious confounders such as caffeine, alcohol, illness, travel and a much later bedtime.
Keep the sound only if the repeated trade-off is clearly useful.

This is self-observation, not a clinical experiment. A sleep diary can reveal a pattern, but it cannot prove the sound caused it.

How ToSleep uses background sounds

The current ToSleep iPhone app includes locally generated sounds in its Wind down area. You can choose a sound, adjust the volume and set a fade-out time. They are optional settling tools, not a claim that white noise treats insomnia or changes a measured sleep stage.

ToSleep’s Apple Watch session estimates sleep from wrist movement and available heart-rate signals. It does not measure bedroom sound level, distinguish white from pink noise or prove that audio caused a change in the estimated sleep timeline. Use repeated nights and your daytime experience as clues, not one score as a verdict.

See the Wind down instructions, how ToSleep works and our guide to sleep-tracker accuracy.

Frequently asked questions

Should white noise play all night?

Not necessarily. If the main problem is settling while outside sounds are active, a fade-out timer may be enough. If disruptive sounds continue all night, continuous masking may feel more useful, but keep the level low and reassess whether sleep actually improves.

Can white noise increase deep sleep?

Current evidence does not justify promising that ordinary white noise increases deep sleep. Some auditory-stimulation studies use precisely timed sounds linked to measured brain activity; that is different from playing a continuous consumer track.

Is a fan the same as white noise?

Not technically. A fan creates a steady mechanical spectrum plus airflow, while mathematically defined white noise contains equal energy per frequency. Both may mask changing sounds, but they are not identical exposures.

Why does white noise help me but annoy someone else?

Noise sensitivity, hearing, preference, room acoustics and the specific unwanted sound all differ. A tool can be useful for one sleeper and disruptive for another without either experience proving a universal rule.

Can ToSleep tell whether white noise improved my sleep?

No. ToSleep can help you compare estimated wrist-based sleep patterns across nights, but it does not measure the room’s sound or establish cause and effect.

Sources

Wellness information, not medical advice.