Brown Noise

What Is Brown Noise, and What Does It Sound Like?

Brown noise is a deep, steady sound. Some people call it Brownian noise or red noise. It has more low tones and less hiss than white noise. What does it sound like? Think of a big waterfall. Or heavy rain on a roof. Or the hum inside a plane. The name has nothing to do with the color brown. It comes from Robert Brown, a botanist. He studied the way pollen grains jiggle in water. The same math behind that jiggle also makes this sound. That deep rumble is why so many people play brown noise for sleep and study.

Press Play. Free Brown Noise Starts Instantly.

No ads, no sign-up, nothing to install: the sound starts the moment you press play. Think of this page as a free brown noise generator and sound machine, right in your browser. The loop has no gap, no click, and no fade. Start it at bedtime and it will still be rumbling 10 hours later when your alarm goes off. It works just as well for study or deep work.

Here is why people like this player:

• No ads, ever. No commercials at 3 a.m. No banners. It is like a radio station that only plays brown noise.
• Very little data. It can stream all night and barely touch your data plan.
• One tap. Press play at night. Press pause in the morning. That is the whole trick.
• Sleep timer. Pick 15 minutes, 12 hours, or any time in between, and the rumble fades down by itself. You never have to wake up to turn it off.
• Black Screen mode. Turn the screen dark while the brown noise keeps playing. No glow in your room, and your battery lasts longer too.

Brown Noise vs. White Noise: Which Helps You Sleep?

Both sounds can cover up the noises that wake you. But they do not sound the same. White noise has equal power at every pitch, and many people find it sharp and hissy. Brown noise gets softer as the pitch goes up. What is left is a warm, low blanket of sound with almost no hiss.

That low end is the whole case for it. Many of the sounds that wake you up are low too. Traffic. A snoring partner. Footsteps from the people upstairs. Brown noise keeps its energy in that same low range, which is the physics argument for it as a masker; no sleep study has yet put brown and white noise head to head. Your brain gets to stop checking every thump, and you drift off.

"The best sound for sleep is not silence. It is a sound so steady your brain stops listening."

What does the research say about brown noise and sleep?

Less than the internet suggests. The one job with solid support is covering other sounds. In a lab that played recorded hospital noise to five sleepers, arousals climbed from about 13 an hour to 48; among the four who then slept a night with a steady noise laid over the top, the rate fell back to about 16 (Stanchina 2005). That study used white noise, not brown, and brown noise has close to no sleep trials of its own.

Beyond masking, the case is weak. A review of 38 studies on steady noise as a sleep aid graded the certainty of the whole body of evidence as "very low" (Riedy 2021). The largest trial we know of split 495 working adults four ways; the 128 who spent four weeks with sleep sounds ended up no better off than a matched comparison group (Vazzaz 2026). Here is where that leaves us: brown noise covers the sounds you have no way to stop, and it gives a racing mind something dull to rest on. It does not treat insomnia. If most nights are a fight, see a doctor.

How to Use Brown Noise for Sleep

The rumble is the easy part. Volume, timing, and knowing what it can and cannot cover are what make it work night after night.

Should brown noise run all night or on a timer?

Match it to your problem. If the hard part is drifting off, a 30-to-90-minute timer does the job; the sound fades once you are gone. If every change in the room wakes you, or the street outside gets busy before dawn, leave it playing quietly until morning. Tap Black Screen and the page goes dark while the sound carries on.

A recent study makes the case for choosing on purpose rather than by habit. Over seven nights with 25 adults, pink noise played on top of outside noise cut REM sleep and made sleep structure worse, while simple earplugs handled the same noise better (Basner 2026). It is a small study, but it argues for the timer when you do not truly need the sound until morning.

How loud should brown noise be for sleep?

Lower than feels natural. Try this: if a normal conversation over the top of it needs a raised voice, it is too loud. Loud steady noise costs more than it gives. In one daytime office study, 45 dB of white noise helped attention, while 65 dB brought more typing mistakes and, next to the quieter setting, slower work and higher stress readings (Awada 2022); nobody has run the same test overnight. And when the street outside is loud enough to hear through a closed window, block it first with earplugs and use brown noise to smooth whatever gets through.

Does brown noise cover snoring and traffic?

Traffic, yes, most of the time. What pulls you out of sleep is the size of the step from quiet to loud, not the loud sound on its own. In the sleep-lab data, people stirred at the same step up, about 17.7 versus 17.5 dB, whether or not a steady noise had been added, and the added noise cut their arousals by two-thirds because it raised the floor (Stanchina 2005). In home sleep recordings pooled from two field studies, about 100 people and nearly 30,000 traffic, train and aircraft noise events, each extra 10 dB of indoor peak raised the odds of waking by roughly 35% (Basner and McGuire 2018). Traffic, footsteps, and rumbling pipes are low sounds, and low is exactly where brown noise keeps its energy.

Snoring is harder. It is loud, it is irregular, and it is a foot from your ear, so a masker would have to be very loud to close that gap. No published study has tested masking sound for a snorer's partner. What has been tested is treating the snorer: in ten couples, fixing one partner's breathing during sleep dropped the other partner's arousals from 21 an hour to 12 (Beninati 1999). Loud snoring with pauses, gasps, or daytime sleepiness belongs in a doctor's office, not in a volume setting.

Is it OK to sleep with brown noise every night?

Kept quiet, yes. When researchers reviewed 34 studies of white and pink noise for sleep, 1,103 people in all, none of the short-term trials reported harm (Capezuti 2022). What nobody has done is follow brown-noise sleepers over years, so that stays an open question. Babies are a separate case with firmer limits on volume and distance; see our baby page.

Who Listens to Brown Noise?

Brown noise has fans far beyond the bedroom. Here are some of the people who keep it on:

• People with ADHD and anyone chasing focus. Many people with ADHD say brown noise quiets the buzz in their heads. The trials so far cover white and pink noise, not brown, and their small attention gains showed up only in the ADHD groups (Nigg 2024). It is also a favorite for studying, coding, and long writing sessions.
• Light sleepers and night-shift workers. The deep rumble swallows street noise and daytime clatter. That helps anyone who sleeps at odd hours or next to a snorer.
• People with ringing ears (tinnitus). Some people find the rumble easier to live with than the ringing. Keep expectations modest: a Cochrane review of eight trials (590 people) found no trial that had even tested sound devices against waiting or plain information, and rated the evidence it did find as low quality (Sereda 2018). If it helps you, keep it at the lowest level that gives relief, and get sudden or one-sided ringing checked by an audiologist.
• Travelers and hotel sleepers. A strange room is often too quiet. The same rumble you sleep to at home plays in any browser, on any phone, anywhere with a signal.

Is Brown Noise the Same as a Fan?

Close, but not quite. A fan gives you three things at once: a low rumble, a mechanical whir from the motor and blades, and moving air. Brown noise is the rumble on its own, with the whir taken out and no hiss added. Many fan sleepers find that is the part they were actually listening for.

If it is the real fan you miss, our Bedtime Fan app plays recordings of actual fans rather than a synthetic copy. If your ears want something brighter than rumble, the classic hiss lives at WhiteNoise.com.

Want White Noise, Pink Noise, Rain, Ocean, or Fan Sounds?

Brown noise is the deepest sound, but it is just one of many. Every set of ears is different. If yours want something brighter, try our app. It has more than 400 sounds, like pink noise, box fans, ocean waves, and thunder, and a new one is added every week. You can mix them and take your mix anywhere.

For a brighter, steadier hiss in your browser, play white noise free at WhiteNoise.com.

Every study behind this page, graded for what it does and does not show, is laid out at slumberstudios.com.

Sources: Stanchina et al. 2005 · Basner & McGuire 2018 · Riedy et al. 2021 · Capezuti et al. 2022 · Awada et al. 2022 · Beninati et al. 1999 · Sereda et al. 2018 · Nigg et al. 2024 · Basner et al. 2026 · Vazzaz et al. 2026. General information, not medical advice — if sleep is a struggle most nights, that is a conversation for a doctor.

Same player, specific uses

• Brown Noise for Sleep — timer settings, all-night playback, and what the low end covers
• Brown Noise for Focus — where the ADHD evidence stands, and the right volume
• Brown Noise for Babies — why the deep end suits the nursery, and the safe-use numbers