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What Is Brown Noise? Focus, ADHD, Tinnitus and Babies

Brown noise is bass-heavy background sound. What it is, why the ADHD focus evidence is borrowed from white noise, and what's known about tinnitus, babies and safe volume.

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What Is Brown Noise? Focus, ADHD, Tinnitus and Babies

Brown noise is steady background sound with most of its energy in the low frequencies. Its power falls about 6 dB for every octave you go up, so it sounds like a low roar, a waterfall or heavy rain, with almost none of white noise's hiss. It took off on TikTok, much of it among people with ADHD who say it helps them focus, and a 2024 review counted tens of millions of social media views on the topic. The research hasn't caught up. No study has tested brown noise for focus in ADHD or for tinnitus. The ADHD evidence comes from white noise.

TL;DR

  1. Brown noise drops about 6 dB per octave, pink about 3 dB, white not at all.
  2. The ADHD focus studies used white noise (12) and pink (1), none brown. Noise helped slightly with ADHD and hurt slightly without.
  3. In tinnitus trials, sound devices haven't beaten no device. Brown noise is untested.
  4. Brown noise is untested on babies. Keep any machine low, far from the cot and on a timer.
  5. To protect your hearing, stay well below 85 dBA.

What is brown noise?

Brown noise contains every frequency you can hear, but the low ones are much louder than the high ones. Its power falls with 1/f squared, about 6 dB per octave. It's also called red noise. It sounds like a low roar: a waterfall, heavy rain, distant thunder or waves crashing.

The name has nothing to do with the colour. It comes from Robert Brown, the Scottish botanist who documented the random jiggling of particles in water now called Brownian motion.

Brown noise vs white noise vs pink noise

Noise typeFrequency profilePower roll-offSounds like
White noiseEqual power at every frequency0 dB per octaveStatic, hiss
Pink noiseLower frequencies louderAbout 3 dB per octaveSteady rain
Brown noiseLowest frequencies dominantAbout 6 dB per octaveWaterfall, heavy rain, distant thunder

With so little high-frequency energy, it has almost none of the hiss that makes some people give up on white noise for sleep. Pink noise sits in between. Green noise has no agreed definition.

Whether it's easier to listen to varies. In a small 2020 Taiwanese study, students' comfort ratings improved with brown and pink noise, not white. In an office study cited by the same authors, participants rejected brown noise through earphones as irritating. When UCL researchers tracked pupil size, a marker of arousal, it didn't differ between the three colours, though each was played for only 10 seconds (Erfanian 2025).

Does brown noise help with focus?

It might, for some people with ADHD. But no ADHD study has used brown noise. The case for it is borrowed from white noise studies.

The theory

Swedish researchers who ran some of the early studies point to stochastic resonance, the idea that a moderate amount of random noise can make a weak signal easier to pick up. In a 2007 Stockholm study, children with and without ADHD did memory tasks with and without white noise. Noise helped the ADHD group and hurt the others. The authors read that as children with ADHD needing more noise than their peers to perform at their best.

What the studies tested

The best summary is a 2024 meta-analysis from Oregon Health & Science University (Nigg 2024). It pooled 13 small studies of 335 children and young adults with ADHD or ADHD symptoms. Twelve used white noise, one used pink, and none used brown. Noise gave a small boost on lab attention tasks (g = 0.25). In people without ADHD, it slightly hurt performance (g = -0.21).

In the 2024 ADHD noise meta-analysis, 12 studies used white noise, one used pink and none used brown.
In the 2024 ADHD noise meta-analysis, 12 studies used white noise, one used pink and none used brown.

The authors say the effect "may well extend to brown noise", and that it isn't clear whether arousal or stochastic resonance is doing the work. A 2022 study of 104 Taiwanese preschoolers fits the same pattern. White noise improved attention scores and reduced hyperactive behaviour in the 52 with ADHD, but the author called it "a burden" for the 52 without.

The one brown-noise focus result comes from outside ADHD research. In the 2020 Taiwanese study of 22 students, brown noise at about 47 dB lifted several cognitive test scores compared with quiet. So did pink and white.

Child psychiatrist Dr Shivnaveen Bains told Cleveland Clinic that brown noise "has gained in popularity mainly because of social media testimonials", and that "it's too soon to tell just how helpful it can be."

Who it may suit

Try it if you have ADHD and white noise grates on you. Skip it if you focus fine in quiet. With no study comparing colours, pick the one you stop noticing. For music options, see focus music for ADHD, ranked by evidence.

Does brown noise help with sleep?

It's barely been studied. A 2021 review of 38 studies of white and similar noise rated the evidence that continuous noise improves sleep "very low".

The bigger caution comes from a 2026 Penn sleep-lab study (Basner 2026). Twenty-five adults spent one adaptation night and six test nights under different sound conditions. On the night with pink noise alone at 50 dB, they got about 19 fewer minutes of REM sleep than on a quiet night. Brown noise wasn't tested, so treat 50 dB as a ceiling, not a target. Dr Sogol Javaheri of Harvard Medical School advises against playing pink or brown noise all night. Her advice is to "use it for a set time" (Harvard Health).

Volume, timers and speaker placement are covered in brown noise for sleep.

Does brown noise help with tinnitus?

No study has tested brown noise for tinnitus. Sound generators are a standard first step in audiology clinics, but the trials behind them are weak. A 2018 Cochrane review of 8 trials with 590 people found none that gave usable data against no device, and rated the evidence it did find low quality. An earlier Cochrane review of 6 trials with 553 people found sound therapy did no better than counselling or relaxation on loudness or severity. No side effects were reported, and the authors note that weak evidence isn't proof it fails.

If low brown noise makes the ringing easier to ignore, it's a low-risk thing to use. If the ringing is new or bothers you, see a GP or audiologist.

Is brown noise safe for babies?

Brown noise hasn't been tested on babies. In a 1990 trial of 40 newborns, 16 of 20 fell asleep within five minutes with white noise, against 5 of 20 without.

Volume is the main worry. A 2014 Pediatrics study tested 14 infant sleep machines at full volume. Measured 30 cm away, every one topped 50 dB, the recommended limit for hospital nurseries, and three went above 85 dB.

REM is the other. It makes up about half of a newborn's sleep. The Penn team wrote that their findings "caution against its indiscriminate use, especially in newborns and toddlers for whom REM sleep is critical for neurodevelopment." No children were in that study.

If you use brown noise for a baby, put the machine as far from the cot as you can, keep it under 50 dB measured at the cot with a meter app, use a timer and ask your paediatrician.

Best uses for brown noise

Good fits

  1. Covering low, steady noise. Its energy sits where traffic rumble and HVAC hum sit. White or pink noise probably covers voices better, though nobody has compared them.
  2. Focus with ADHD, if white noise grates.
  3. A short wind-down, with a timer to switch it off.

Skip brown noise if

  • You focus well in quiet. Noise slightly hurt performance in people without ADHD.
  • Low, rumbling sound feels oppressive to you.
  • It only works for you when it's loud. That's a hearing risk.

How to use brown noise safely

Volume matters

Long or repeated exposure at or above 85 dBA can cause hearing loss, while 70 dBA and below is unlikely to, even over long periods (NIDCD). Normal conversation is about 60 to 70 dBA. If you have to raise your voice to be heard at arm's length, the noise is probably above 85 dB (NIOSH).

The ear is less sensitive to bass, so brown noise can seem quieter than it is. A free sound meter app gives you a real number.

Duration guidelines

No study has set a time limit for brown noise. Volume matters more than minutes.

Use caseWhat the sources sayWhy
Focus sessionNo tested limit; keep it well below 70 dBALong exposure under 70 dBA is unlikely to harm hearing
Falling asleepUse a timer; 50 dB at mostA night of pink noise at 50 dB cut REM by about 19 minutes
Masking noise (daytime)As needed, low volumeSame hearing rule as focus
All nightAvoidUntested for brown noise; all-night pink noise cut REM

Dr Bains suggests 10 to 15 minutes at a time. That's her advice, not a study finding.

Where to find brown noise

Any long, non-looping track or noise generator app will do. A repeat you start to notice becomes one more thing to distract you.

Brown noise and NSDR

They're different tools. Brown noise plays in the background while you do something else. Non-sleep deep rest is a guided practice. You lie still, stay awake and follow a voice through your body and breathing for 10 to 30 minutes. Four small trials use the NSDR name, and most of the wider research is on yoga nidra, which it's built on.

If your room is noisy, low brown noise under a guided track is an option. NSDR.co is free.

Common mistakes with brown noise

  1. Playing it too loud. Start quiet, raise it only until the distraction fades, and measure it.
  2. Leaving it on all night. A night of continuous pink noise at 50 dB cut REM sleep in the Penn study. Use a timer.
  3. Expecting a treatment. The ADHD benefit, from white noise, was small. It doesn't replace ADHD care or a tinnitus assessment.
  4. Never trying the alternatives. Pink noise, nature sounds or silence may suit you better.

This is general information, not medical advice. If focus problems, tinnitus or poor sleep last for weeks, see a doctor or audiologist, and ask a paediatrician before using a sound machine for a baby.

FAQ

Is brown noise better than white noise for sleep?

Neither is better for everyone, and neither has good evidence behind it. Brown noise has almost no hiss and its bass suits traffic or HVAC noise, while white noise probably covers voices better. More in brown noise for sleep.

Can brown noise damage your hearing?

Yes, brown noise can damage hearing if it's loud for long enough, like any sound. Long or repeated exposure at 85 dBA or more can cause hearing loss. At 70 dBA or below, damage is unlikely even over long periods. Check with a meter app.

Does brown noise help with ADHD?

Brown noise hasn't been tested for ADHD. The 2024 meta-analysis found a small benefit on attention tasks from 12 white-noise studies and 1 pink, with no brown-noise studies. Its authors think brown noise may work the same way.

What's the difference between brown noise and pink noise?

The difference is how fast the power falls as pitch rises. Pink noise drops about 3 dB per octave and sounds like steady rain. Brown noise drops about 6 dB per octave, so it's deeper, closer to a waterfall or distant thunder.

How long should I listen to brown noise?

Listen to brown noise as long as you like for focus, provided the volume stays low. No study has set a time limit. Keep it well under 70 dBA. For sleep, use a timer rather than playing it all night.

Sources