Brown noise is everywhere at bedtime now, and it's easy to see why: deep, soft, steady. The research is thinner than the popularity. The sleep reviews we found studied white noise, pink noise and mixed audio, and none of them tests brown noise on its own. This page is about sleep, so it sticks to what published sources measured and where they stop. Brown noise falls about 6 dB per octave, which is why it sounds lower than white or pink. Nothing here promises a result.
What did the studies look at?
The broadest source is a 2022 systematic review in the Journal of Clinical Sleep Medicine. It gathered 34 studies with 1,103 participants in total: 18 on white noise, 11 on pink noise and 6 on "multiaudio", which means combinations of noise, music or silence.
Brown noise is not mentioned in it. If you want the sound itself first, we explain what brown noise is and why it sounds deeper.
A 2021 systematic review by Riedy and colleagues looked at noise as a sleep aid and mostly focused on white noise. A 2025 perspective in the journal Sleep, by Vazzaz and colleagues, names brown noise only once, in a list: "colored noises (such as white, pink, and brown noise)". It reports no brown noise evidence of its own.
So when a page says "studies show brown noise helps you sleep", the studies it means are usually about a neighbouring sound. Read the fine print.
What did they find?
In the 2022 review, 19 of the 34 studies reported improved sleep outcomes: 6 white noise, 9 pink noise and 4 multiaudio. That sounds like a clear win. Then you read how the authors weighed it.
- The pink noise studies had the highest share of positive findings, but they were generally of weaker methodological quality.
- The multiaudio studies had the lowest risk of bias, but none of them measured sleep with polysomnography, the overnight lab recording.
- Designs, measures and interventions varied so much that the authors could not combine the results into one figure.
- No adverse effects were reported with short-term use.
Their conclusion was plain: there was no clear evidence from the review that auditory stimulation effectively improves sleep. They asked for more rigorous randomised trials, particularly among people with insomnia.
The 2025 perspective in Sleep agrees. It calls the evidence for coloured noises "equivocal" and says two systematic reviews, mostly of white and pink noise, "found no consistent evidence of their effectiveness in improving sleep outcomes". It rates the Riedy review as having "very low" quality of evidence. A 2021 review of the field adds the other side: continuous noise tended to be helpful for falling asleep and staying asleep, "even though evidence for such a beneficial effect was low".
One more detail from the 2025 perspective: the most consistent improvements in sleep quality appeared in hospital-based studies. A ward is loud and unpredictable, so a steady sound has a lot to cover. A quiet bedroom at home is a different setting, and the studies do not tell us how much carries over.
What did they not find?
They did not find a trial of brown noise for sleep, and they did not find a head-to-head comparison of brown against white or pink. Those are the two questions most people are asking.
They also did not find proof of long-term effects. The 2022 review reported no adverse effects with short-term use, which is not the same as a finding about nights on end.
What people report online, that brown noise feels calmer or masks a neighbour's footsteps, is a fair description of a preference. It is not a measurement, and we have no sourced numbers for it. Masking is the plausible idea behind most of this: steady sound covers sudden sound. That idea is about any steady noise, not brown noise in particular. If you play a steady sound for hours, sleeping with white noise all night covers what those studies measured.
Here is the short version of the gap. A pink noise result tells you about pink noise. Brown noise sits further down the spectrum, with more weight in the low pitches and less hiss, so it is reasonable to ask whether it behaves the same way. It's a fair question, and the published reviews don't answer it.
How do you try it?
Start with volume, because that is the part the sources agree on least. In the studies that reported a level, it was 42 to 50 dB, and the WHO sets 45 dB as the sound level inside bedrooms, according to the 2021 review of acoustic modulation. The same review notes that volume has rarely been reported and has not been tested systematically. So there is no proven setting. Keep it low, and see how loud is too loud for listening all night.
Then run a small experiment on yourself:
- Pick one sound and one volume for about two weeks.
- Note how long you take to settle and how you feel in the morning.
- Compare with your usual nights, and drop it if you do not like it.
In Hush Machine, brown noise is made live on your phone, so nothing loops or repeats. One dial runs from white to deep brown, and a timer with a fade lets you stop it without a sudden end. It is coming to iPhone.
If your sleep is poor for weeks, or you have ringing in your ears, see a doctor or audiologist. Background sound is not a substitute.
Bottom line
Brown noise is popular and pleasant to many people, but the sleep research we found does not test it. Reviews of white and pink noise found no clear evidence either way, and rated what exists as low quality. If you like how it sounds, keep the volume low and judge it by your own nights. More on sleep and sound is on the sleep page.
Questions
- Is there research on brown noise and sleep?
- Very little that tests brown noise itself. A 2022 review of 34 studies covered white noise, pink noise and mixed audio, and does not mention brown noise. A 2025 paper in Sleep lists brown noise once, beside white and pink.
- Is brown noise better than white noise for sleep?
- None of the sources we found compares them for sleep, so nobody can say. Brown noise has more low pitch and less hiss than white noise, and some people simply prefer how it sounds.
- Does the research say brown noise is harmful?
- The 2022 review reported no adverse effects with short-term use, but it did not test brown noise, and it did not test years of use. Keep the volume low.
- How loud should I play it?
- Studies that reported a level used 42 to 50 dB, and the WHO sets 45 dB as the level for inside bedrooms. Volume has not been tested systematically, so there is no proven number.