What Is Brown Noise, and Is It Good for Sleep?

Brown noise is a steady, deep sound with most of its energy in the low frequencies. It sounds like a rumble rather than a hiss: closer to heavy surf, a waterfall heard from a little way off, or the inside of a train cabin than to TV static.

It has become one of the most popular sounds for sleep and focus in the last few years, mostly by word of mouth. Here's what it actually is, and what it can and can't do.

Brown noise in one sentence

Brown noise is random noise where the bass is loud and the treble is quiet, which is why it sounds deep and soft instead of bright and hissy.

Why is it called "brown"?

Not because of the colour. The name comes from Brownian motion, the random jittering of tiny particles in a liquid, first described by the botanist Robert Brown in 1827. If you turn that kind of random wandering into sound, you get brown noise. (It's also sometimes called red noise, which keeps it in line with the other noise "colours".)

How brown noise differs from white and pink noise

All three are steady, random sounds. The difference is how their energy is spread from low to high pitch:

• White noise has equal energy at every frequency. It sounds bright and hissy, like static or an air vent.

• Pink noise turns the treble down a little. It sounds fuller and softer, like steady rain.

• Brown noise turns the treble down a lot more. Each time the pitch doubles, the volume drops by about 6 decibels. What's left is mostly low-end rumble.

If white noise is a hiss and pink noise is rain, brown noise is the ocean. We go into all of the colours in more detail in our guide to brown vs white vs pink noise.

What brown noise sounds like in real life

You've almost certainly heard sounds that sit close to brown noise:

• Heavy surf, especially from a distance

• A large waterfall or a fast river

• Distant, rolling thunder

• The cabin of a plane, train or ferry

• Strong wind against a building

That's part of its appeal. It's a sound the brain already files under "big, steady and harmless".

Is brown noise good for sleep?

For many people, yes, but probably not for magical reasons.

What it does well:

• It masks low sounds. Traffic rumble, a neighbour's bass, a partner's snoring and building hum all sit in the low frequencies. Brown noise covers that range better than white noise does.

• It's easy to tune out. Without white noise's high-frequency hiss, many people find they stop noticing brown noise within a few minutes.

• It's calming to a lot of listeners. Deep, steady sounds tend to read as safe and slow.

What the evidence doesn't say: there's very little published sleep research on brown noise specifically. Most noise-and-sleep studies use white or pink noise. So if someone tells you brown noise is "scientifically proven" to give you deeper sleep, that's ahead of the evidence. What is well supported is the general idea that a steady background sound makes sudden noises less disruptive.

The best test is your own: try it for a week, at low volume, and see how you feel.

Brown noise for focus and ADHD

A lot of the recent interest in brown noise comes from people with ADHD who say it quiets mental chatter and helps them concentrate. Those reports are worth taking seriously, but the research is thin. There are studies suggesting background noise can help some people with attention difficulties focus, though most of them used white noise rather than brown. If it works for you, that's a good enough reason to use it. Just treat it as a tool to try, not a treatment.

How to use brown noise for sleep

• Keep it quiet. Aim for just above the background noise of your room. A rough ceiling is around 50 decibels, about the level of moderate rain.

• Don't put the speaker by your ear. A metre or two away is plenty.

• Decide on a timer or all night. If you only struggle to drift off, let it fade after 30 to 60 minutes. If you wake to noises during the night, leave it running.

• Give it a few nights. Any new sound takes a little getting used to.

Synthetic brown noise vs the real thing

Most brown noise tracks are generated: a computer produces a perfectly even rumble that never changes. That works, but some people find it flat or slightly oppressive over a whole night.

The alternative is a real recording of a sound that naturally sits in the same range: surf, a river, distant thunder, a ferry engine at night. You get the same deep masking, plus small, irregular details that make it feel like a place rather than a machine.

Sleep Sounds by Wonderland gives you both. Every sound in the app is recorded on location, including recordings that sit in the same deep range as brown noise: a glacier river, a storm over the Dordogne Valley and the Bergen night ferry. The app's sleep frequencies, including brown noise, are built from original recordings too, rather than produced purely by software. Try brown noise on its own, or layer it under one of the recordings and balance the two until it sounds right.

FAQ

Is brown noise the same as red noise?
Yes. The two names are used for the same thing.

Is brown noise better than white noise?
It depends on your ears and your environment. If white noise feels harsh, or the sounds keeping you awake are low ones like traffic or snoring, brown noise is usually the better choice.

Is it safe to sleep with brown noise every night?
At a low volume and with the speaker away from your head, there's no evidence it causes harm for adults. Keep it quiet.

Can brown noise help with tinnitus?
Some people find a low, steady sound makes tinnitus less noticeable at night. If tinnitus is bothering you, it's worth talking to a doctor or audiologist too.