Pink Noise vs White Noise vs Brown Noise: What Sleep Research Supports

Every few months a new color of noise goes viral. White noise was the old default, pink noise took over sleep TikTok, and brown noise arrived with a reputation for calming everything from a busy brain to a barking dog. The sleep literature is smaller and messier than the videos suggest, so this post grades each one separately and says where the evidence runs out.

1. What the colors actually mean

The colors describe how sound energy is spread across pitch. White noise has equal energy at every frequency, so it sounds like static or a hissing vent. Pink noise has more energy in the lower frequencies, closer to steady rain or wind. Brown noise leans lower still and sounds like a deep rumble or a distant waterfall.

That spectral difference is real. Whether it changes how you sleep is a separate question, and one early test found little reason to expect a dramatic gap. In a small laboratory study of 31 listeners, pupil size, a marker of arousal, did not differ between 10-second clips of white, pink and brown noise.

Citation: Erfanian M, Chait M, Kang J. Pupil-linked arousal does not differ between 'white', 'pink' and 'brown' noises. Int J Psychophysiol, 2025. PubMed: 41110471

2. Pink noise: strong lab results, and the catch

Pink noise has the most interesting data, so it gets the most attention. The key work comes from sleep labs studying slow-wave sleep, the deep stage most associated with physical restoration and memory. In a landmark study, researchers played brief sounds timed to the up-phase of each sleeper's own slow oscillation, tracked live on EEG. That in-phase stimulation strengthened the slow oscillation and was associated with better recall of word pairs the next morning. Sounds played out of phase did nothing.

Citation: Ngo HV, Martinetz T, Born J, Molle M. Auditory closed-loop stimulation of the sleep slow oscillation enhances memory. Neuron, 2013. PubMed: 23583623

A later study repeated the approach in 13 adults aged 60 to 84 using pulses of pink noise. Slow-wave activity rose during the stimulation windows, though not across the whole night, and next-morning word recall was better than on the sham night. It was one night per condition, in a small sample.

Citation: Papalambros NA, Santostasi G, Malkani RG, et al. Acoustic enhancement of sleep slow oscillations and concomitant memory improvement in older adults. Front Hum Neurosci, 2017. PubMed: 28337134

Here is the catch. Both studies used closed-loop equipment: EEG electrodes, a real-time algorithm and short bursts of sound. That is not the same as pressing play on an eight-hour rain-and-pink-noise track. Even the looser version of the experiment, non-phase-locked pink noise, was run in a hospital-style lab with a technologist scoring sleep stages live and delivering sound only during non-REM sleep. In those eight participants, the share of deep sleep was higher on the pink noise night. The authors also found that sounds meant to disrupt sleep increased slow-wave activity momentarily while wrecking sleep continuity, which is a useful warning that more slow-wave power is not automatically better sleep. Several authors reported ties to the company that makes the stimulation software, which is worth knowing when reading the result.

Citation: Schade MM, Mathew GM, Roberts DM, Gartenberg D, Buxton OM. Enhancing slow oscillations and increasing N3 sleep proportion with supervised, non-phase-locked pink noise and other non-standard auditory stimulation during NREM sleep. Nat Sci Sleep, 2020. PubMed: 32765139

Grade for the lab version: promising. Grade for the all-night app version: unproven.

3. Pink noise all night: thinner and more mixed

Does steady, open-loop pink noise help in a real bedroom? The honest answer is that a few small studies lean positive and one leans the other way. A Swedish pilot with 12 healthy adults used polysomnography across five nights in acoustically isolated bedrooms. Traffic noise of 45 to 65 dB at its peaks produced brief, repeated sleep fragmentation, and continuous 45 dB pink noise played underneath attenuated them. Sample size and participant homogeneity limit what this can tell you, as the authors say themselves.

Citation: Vincens N, Nause A, Basner M, et al. Pink noise reduces impact of traffic noise on sleep and the blood metabolome: a cross-over pilot study. Commun Med (Lond), 2026. PubMed: 41513961

Now the counterweight. In a study of 72 people sleeping at home with a headband monitor, open-loop pink noise did not improve a pattern-recognition insight task compared with silent sleep, and it shortened the first stretch of light N1 sleep that predicted insight. The authors suggest steady pink noise may alter normal sleep architecture in ways that are not always helpful. That is one task in one study, so treat it as a flag, not a verdict.

Citation: Vickrey B, Lerner I. Overnight exposure to pink noise could jeopardize sleep-dependent insight and pattern detection. Front Hum Neurosci, 2023. PubMed: 38107593

Zooming out, a 2022 systematic review of 34 studies and 1,103 people found positive sleep findings in about 82 percent of pink noise studies, 33 percent of white noise studies and 67 percent of multi-sound studies. That looks like a win for pink noise until you read the rest: the authors concluded there was no strong evidence to support auditory stimulation, risk of bias was higher for pink and white noise than for the multi-sound studies, and no adverse effects were reported with short-term use.

Citation: Capezuti E, Pain K, Alamag E, Chen X, Philibert V, Krieger AC. Systematic review: auditory stimulation and sleep. J Clin Sleep Med, 2022. PubMed: 34964434

4. White noise: mixed, and graded very low

White noise has the longest history and the weakest scorecard. A systematic review of 38 articles on continuous white or broadband noise found findings at both extremes, with some studies suggesting it improves sleep and others suggesting it disrupts it. Using GRADE criteria, the authors rated the quality of evidence that continuous noise improves sleep as very low, which they noted contradicts how widely it is used.

Citation: Riedy SM, Smith MG, Rocha S, Basner M. Noise as a sleep aid: a systematic review. Sleep Med Rev, 2021. PubMed: 33007706

The best case for white noise is masking. In a small polysomnography study from an intensive care context, recorded ICU noise pushed the arousal index from about 13 per hour at baseline to about 48 per hour. Adding mixed-frequency white noise brought it back to about 16. The sample was tiny, four people completed all conditions, but the mechanism is believable: steady sound shrinks the gap between background and sudden noise, and the jump is what wakes you.

Citation: Stanchina ML, Abu-Hijleh M, Chaudhry BK, Carlisle CC, Millman RP. The influence of white noise on sleep in subjects exposed to ICU noise. Sleep Med, 2005. PubMed: 16139772

One randomized crossover study in 18 healthy adults used a model of transient insomnia, with bedtime moved 90 minutes earlier. Broadband sound at about 46 dB, against a room at about 40 dB, cut the time to reach stage 2 sleep from a median of 19 to 13 minutes. Young, healthy and one night of testing, so it says little about chronic sleep trouble.

Citation: Messineo L, Taranto-Montemurro L, Sands SA, et al. Broadband sound administration improves sleep onset latency in healthy subjects in a model of transient insomnia. Front Neurol, 2017. PubMed: 29312136

Grade: situational. Useful for covering a noisy street, not shown to improve sleep in a quiet room.

5. Brown noise: the popular one with no sleep trials

Brown noise is the one that most outruns its evidence. A PubMed search for brown noise alongside sleep returns three records, none of which is a controlled trial of brown noise for sleep. The closest thing is a hospital study of 54 patients in which an app rotated through white noise on day one, pink on day two and brown on day three, and sleep ratings improved on each day against controls. That is a quasi-experimental design with a four-point rating scale and no way to separate the colors from each other.

Citation: Warjri E, Dsilva F, Sanal TS, Kumar A. Impact of a white noise app on sleep quality among critically ill patients. Nurs Crit Care, 2022. PubMed: 34931413

If brown noise helps you, it may well help the way any pleasant, steady sound helps, by masking and by giving a busy mind something to rest on. That is a reasonable personal reason to use it. It is not evidence that brown noise outperforms the others, and anyone claiming it is has gotten ahead of the research.

Grade: not graded. There is nothing to grade.

6. Volume and hearing: the part people skip

Louder is not better, and this is where sleep sound can go wrong. The trials that showed benefit used quiet levels, around 45 to 46 dB in rooms where the unmasked baseline was roughly 40 dB. The systematic review of continuous noise explicitly warned that it may negatively affect sleep and hearing, and called for more research before it is promoted as a sleep aid.

The clearest hearing data comes from infant sleep machines. When 14 devices were measured at maximum volume, every one produced more than 50 A-weighted decibels at 30 centimeters, and three exceeded 85. Played for more than eight hours, 85 dBA exceeds current occupational limits for adult noise exposure. That study was about babies and their smaller ear canals, but the logic transfers: volume multiplied by hours is what matters. If you use sleep sound, a speaker across the room at a low level is a safer default than earbuds at a high one, and a parent considering it for a child should ask a pediatrician. Anyone with hearing concerns should check with an audiologist or physician.

Citation: Hugh SC, Wolter NE, Propst EJ, Gordon KA, Cushing SL, Papsin BC. Infant sleep machines and hazardous sound pressure levels. Pediatrics, 2014. PubMed: 24590753

7. If you want to try it anyway

The research suggests a few sensible ground rules, none of them dramatic. Treat it as a masking tool for a noisy environment rather than a sleep upgrade for a quiet one. Keep it low enough that you can still hear a normal conversation over it. Pick one sound and give it a couple of weeks instead of switching nightly, since the three colors have not been shown to differ in effect. And notice honestly whether you sleep better, because the average study result is small and some people do worse.

One more thing worth knowing: if a sound track claims to deliver slow-wave enhancement from an app alone, check whether it is open-loop. Every strong positive result above came from a lab with sensors, and the open-loop version has at least one negative study.

Where Lunia fits

Sound changes the room around you. Whatever is keeping your mind switched on at 11pm sits on the other side of that wall. Lunia Restore is a melatonin-free capsule with three listed ingredients: magnesium bisglycinate (500 mg, which delivers 90 mg of elemental magnesium), L-theanine (300 mg) and apigenin (50 mg). A 2025 meta-analysis of 19 trials found L-theanine improved subjective sleep quality and sleep onset, and research points to a 200 to 450 mg daily range for L-theanine.

Citation: Bulman A, D'Cunha NM, Marx W, Turner M, McKune A, Naumovski N. The effects of L-theanine consumption on sleep outcomes: a systematic review and meta-analysis. Sleep Med Rev, 2025. PubMed: 40056718

There is no randomized trial on the finished Lunia formula, so the evidence is at the ingredient level. Individual results may vary. For many people, a quiet room, a consistent bedtime and a low-volume sound source cover the basics, and a supplement is a separate decision.

Learn more about Lunia Restore

Frequently Asked Questions

Is pink noise better than white noise for sleep?

Pink noise has more laboratory data on slow-wave sleep, and a larger share of pink noise studies reported positive findings in one systematic review. But the strongest results used EEG-timed bursts, not all-night tracks, and the review found no strong evidence for either color. Neither has been shown to beat the other in a head-to-head sleep trial that we could find.

Does brown noise help you sleep?

There is no controlled trial of brown noise for sleep that we could find. It may help some people the way any steady, pleasant sound can, but the research does not show it works better than white or pink noise.

How loud should sleep sounds be?

The studies with positive results used roughly 45 to 46 dB, about the level of a quiet room. A practical rule is to keep it low enough to hold a normal conversation over it. Sustained high volume carries hearing risk, and anyone with hearing concerns should ask an audiologist or physician.

Is it safe to play noise all night?

Short-term use in the reviewed studies came with no reported adverse effects, but the authors of another review flagged that continuous noise may negatively affect sleep and hearing and called for more research. Low volume and a speaker placed away from your head are the lower-risk choices.

Does pink noise increase deep sleep?

In lab studies with live monitoring, timed or supervised pink noise was associated with more slow-wave activity or a higher share of N3 sleep. Those samples were small, often one or a few nights, and the findings have not been shown to carry over to a phone app played overnight.

Are sleep sound machines safe for babies?

A Pediatrics study measured 14 infant sleep machines and found all exceeded 50 dBA at 30 cm, with three above 85 dBA, a level that over eight hours exceeds adult occupational limits. Ask your pediatrician about volume, distance and duration before using one.

Is a speaker or earbuds better for sleep noise?

No study we found compares the two directly. The trials with benefit used speakers in the room at low levels. Earbuds put sound close to the ear for hours, so the volume question matters more with them.

The Bottom Line

Pink noise has the only evidence worth getting excited about, and that evidence comes from labs with sensors, not from a track on your phone. White noise is a masking tool with a mixed record. Brown noise has no sleep trials at all. Across all three, the studies that found benefit used low volume, and the cautious reading is that a quiet, steady sound can help in a noisy room and may do little in a quiet one. Choose by what you enjoy, keep it low, and judge by how you actually sleep.

References

1. Erfanian M, Chait M, Kang J. Pupil-linked arousal does not differ between 'white', 'pink' and 'brown' noises. Int J Psychophysiol. 2025. PubMed: 41110471
2. Ngo HV, Martinetz T, Born J, Molle M. Auditory closed-loop stimulation of the sleep slow oscillation enhances memory. Neuron. 2013. PubMed: 23583623
3. Papalambros NA, Santostasi G, Malkani RG, et al. Acoustic enhancement of sleep slow oscillations and concomitant memory improvement in older adults. Front Hum Neurosci. 2017. PubMed: 28337134
4. Schade MM, Mathew GM, Roberts DM, Gartenberg D, Buxton OM. Enhancing slow oscillations and increasing N3 sleep proportion with supervised, non-phase-locked pink noise and other non-standard auditory stimulation during NREM sleep. Nat Sci Sleep. 2020. PubMed: 32765139
5. Vincens N, Nause A, Basner M, et al. Pink noise reduces impact of traffic noise on sleep and the blood metabolome: a cross-over pilot study. Commun Med (Lond). 2026. PubMed: 41513961
6. Vickrey B, Lerner I. Overnight exposure to pink noise could jeopardize sleep-dependent insight and pattern detection. Front Hum Neurosci. 2023. PubMed: 38107593
7. Capezuti E, Pain K, Alamag E, Chen X, Philibert V, Krieger AC. Systematic review: auditory stimulation and sleep. J Clin Sleep Med. 2022. PubMed: 34964434
8. Riedy SM, Smith MG, Rocha S, Basner M. Noise as a sleep aid: a systematic review. Sleep Med Rev. 2021. PubMed: 33007706
9. Stanchina ML, Abu-Hijleh M, Chaudhry BK, Carlisle CC, Millman RP. The influence of white noise on sleep in subjects exposed to ICU noise. Sleep Med. 2005. PubMed: 16139772
10. Messineo L, Taranto-Montemurro L, Sands SA, et al. Broadband sound administration improves sleep onset latency in healthy subjects in a model of transient insomnia. Front Neurol. 2017. PubMed: 29312136
11. Warjri E, Dsilva F, Sanal TS, Kumar A. Impact of a white noise app on sleep quality among critically ill patients. Nurs Crit Care. 2022. PubMed: 34931413
12. Hugh SC, Wolter NE, Propst EJ, Gordon KA, Cushing SL, Papsin BC. Infant sleep machines and hazardous sound pressure levels. Pediatrics. 2014. PubMed: 24590753
13. Bulman A, D'Cunha NM, Marx W, Turner M, McKune A, Naumovski N. The effects of L-theanine consumption on sleep outcomes: a systematic review and meta-analysis. Sleep Med Rev. 2025. PubMed: 40056718

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