Brown noise is popular as a work soundtrack, but the research behind that popularity is thin. The name comes from Brownian motion, not from the colour. The attention studies we found tested white and pink noise, and a 2024 review of them found no studies of brown noise at all. This page covers what the name means, what those studies measured and what nobody has tested yet. It sits in our focus topic, so it sticks to what published sources report and does not promise a result.
Where does the name brown noise come from?
The name honours Robert Brown, the botanist who documented the erratic motion of particles in water. The signal that this kind of motion produces is called Brownian noise, or random walk noise. It was never named for the colour, which is why you will also see it called red noise.
What matters for how it sounds is the spectrum. Brownian noise has a spectral density proportional to 1/f², so each doubling of frequency cuts the power to a quarter. In decibels that is a fall of 6 dB per octave, or 20 dB per decade. Most of the energy sits at low frequencies, which is why it sounds like a deep rumble with little hiss. Our guide to what brown noise is goes through how that slope compares with pink and white noise.
Red noise is an analogy to light. White light contains all wavelengths and white noise contains all frequencies equally. Red sits at the long-wavelength end of the visible spectrum, and this noise is strong at the low end of the sound spectrum.
What did studies on noise and attention find?
The broadest source we found is a 2024 systematic review and meta-analysis by Nigg and colleagues in the Journal of the American Academy of Child and Adolescent Psychiatry. It pooled 13 studies with 335 children and college-age young adults who had ADHD or elevated ADHD symptoms.
In those groups, white and pink noise gave "a small but statistically significant benefit" on laboratory attention tasks, with an effect size of g = 0.249. A separate comparison of 11 studies with 335 people who did not have ADHD went the other way. There, white and pink noise had a small negative effect on task performance, g = −0.212.
Two things limit what you can take from this. The tasks were short, controlled lab tests, not a day of work or study. And the authors say more studies are needed to confirm the effects and to identify safe and appropriate decibel levels. The review makes no claim about adults at a desk, and we do not read more into it than the authors do. The effects are small, and they come from pooled lab studies, so they say little about any one person.
What the studies did not find
The same review set out to include white, pink and brown noise. It reports that "No studies of brown noise were identified." So the benefit above belongs to white and pink noise. Nobody has pooled a result for brown noise, positive or negative.
A common explanation is that coloured noises change how alert you are, so brown noise might do something different from white. A 2025 study in the International Journal of Psychophysiology tested this directly. Erfanian, Chait and Kang measured pupil size, a marker of arousal, in 31 listeners who heard white, pink and brown noise for 10 seconds each. They found no significant change in pupil size across the three noises.
That result is narrow. It covers brief exposure in people hearing these sounds for the first time. It measures arousal, not attention or output. It does not show that brown noise is useless for concentration. It does mean the idea that each colour has its own distinct effect on alertness is not supported by that test.
If you came here from our piece on brown noise for sleep, the pattern is the same. The sound is popular, the published research covers its neighbours, and the honest summary is that brown noise itself has not been tested.
Plenty of people say they like a deep, steady sound while they work. That's a preference, and we don't count it as evidence of an effect.
How do you try it for yourself?
Think of it as a small test of your own. Pick one task you do often and play the same sound at a modest level for a few sessions. Then try the same task with silence, or with a different colour, and see which you would rather work with. Keep the volume where you could still hear someone speak to you. Write down how the session went right afterwards, in a line or two, because memory flatters whatever you tried last. If the sound makes no difference, that is a fine answer too, and you can stop using it.
If you have ADHD or any other condition and are wondering about sound, ask your clinician. A background sound is not a replacement for anything they have advised.
Hush Machine makes its noise live on the phone, so nothing loops and nothing repeats. One dial runs from white to deep brown, and you can set a timer. The Brown Noise sound page describes how that end of the dial sounds. Hush Machine is coming to iPhone.
Bottom line
Brown noise is named after Robert Brown and falls 6 dB per octave. The best review of noise and attention found a small lab benefit for white and pink noise in ADHD groups and no studies of brown noise. Whether brown noise helps you focus is something you can only find out by trying it.
Questions
- Does brown noise help you focus?
- Some people like it as a steady background while they work, but the 2024 meta-analysis of noise and attention found no studies of brown noise. There is no measured result for it, so nobody can say it helps.
- Why is it called brown noise?
- It is named after Robert Brown, who described the erratic motion of particles in water. It has nothing to do with the colour brown.
- Is brown noise the same as red noise?
- The two names are used for the same 1/f squared spectrum. Red is an analogy to light, where red sits at the low end, because brown noise has most of its power at low frequencies.
- Is it safe to play brown noise loudly while working?
- Keep it at a comfortable, modest level. The authors of the 2024 review say that safe decibel levels still need to be identified.