White noise sounds bright, like static. Pink noise is softer, like steady rain. Brown noise is deep, like a distant waterfall. The three differ only in how their energy is spread between low and high pitches. Research on focus has tested white and pink noise, never brown, so the best choice is the one you can comfortably work with.
Not medical advice. Treat noise as part of your work setup, not as therapy. If focus problems affect your daily life, talk to a doctor or a qualified clinician.
What is the difference between white, pink and brown noise?
All three are random noise: a hiss with no melody, rhythm or words. What changes is the balance between low and high frequencies.
- White noise has equal power at every frequency, a flat spectrum. Because each octave up contains twice as many frequencies as the one below, most of that energy lands in the high range, which is why white noise sounds bright and hissy.
- Pink noise has equal power in every octave. By the standard definition (see Colors of noise), its power falls by about 3 dB per octave as pitch rises, a “1/f” spectrum, so it sounds more balanced and softer.
- Brown noise, by the same Colors of noise definitions, falls by about 6 dB per octave, a “1/f²” spectrum. Most of its energy sits in the low range, so it sounds like a rumble. It is named after Brownian motion, not the colour, and is also called red noise.
The 2024 Nigg et al. meta-analysis describes the sounds this way: white noise like radio static, pink noise like heavy rain, and brown noise like ocean waves or rolling thunder.
| White noise | Pink noise | Brown noise | |
|---|---|---|---|
| Sounds like | Static, a fan up close | Steady rain, wind | Waterfall, distant thunder |
| Spectrum | Flat: equal power per frequency | Falls gently as pitch rises (1/f) | Falls steeply as pitch rises (1/f²) |
| Character | Bright, hissy | Balanced, soft | Deep, muffled |
| Studied for focus? | Yes, most studies | One study | No studies found |
| Listen | White noise | Pink noise | Brown noise |
Does noise help you focus?
The honest answer: for some people, a little, in short lab tasks. The evidence is small and mixed.
- Noise and ADHD. In a 2024 meta-analysis, Nigg and colleagues pooled 13 studies with 335 young people with ADHD or high ADHD symptoms. In their analysis, white or pink noise gave a small benefit on lab tasks. Nigg and colleagues note that twelve of the included studies used white noise and one used pink.
- Noise for everyone else. In the Nigg meta-analysis, comparison groups without ADHD did slightly worse on the tasks with white or pink noise than without it.
- Short sessions only. The studies used brief noise exposure, a few minutes, at varied volumes. Nobody has measured effects over weeks of daily use.
- One school study. In a 2010 study, Söderlund and colleagues tested 51 pupils: background white noise helped the inattentive children on a memory task and hurt the attentive ones. The authors say the result “needs replicating in a larger sample”.
- Speech is the bigger problem. A 2018 meta-analysis on reading (Vasilev et al.) found that background speech disrupts reading more reliably than non-speech noise does. Steady noise has no words to follow, which is one reason people use it to cover chatter.
What does the research say about brown noise?
There is none yet. Nigg et al. found no studies of brown noise in their search. The authors suggest the white noise results may extend to brown noise, but say that still has to be tested. Brown noise is popular because many people find it easier to listen to for a long time, not because studies have shown it works better.
Which noise should you try first?
Start from what bothers you and what you can stand for an hour:
| Your situation | Try first | Why |
|---|---|---|
| You find white noise harsh | Brown noise | Little high-pitched energy, so less hiss |
| You want a middle ground | Pink noise | Softer than white, brighter than brown |
| You want the most-studied option | White noise | Almost all focus studies used it |
| People talking nearby | Pink noise or rain | A steady sound with no words to follow |
| Low hum of traffic or machines | Brown noise | Its energy sits in the same low range |
| You prefer silence | Silence, or quiet ambient music | The research found noise can hurt some people’s performance |
How do you try each noise on Nova Focus?
- Open the sounds page and put on headphones or speakers at a low volume.
- Play white, pink and brown noise for two minutes each. Notice which one fades into the background fastest.
- Pick one and start a focus timer, for example 25/5 or 50/10.
- Work a few sessions with it, then a few in silence on the same kind of task.
- Keep whichever setup gave you better sessions. If none helped, silence is a perfectly good answer.
Each sound page has its own volume control and a timer, so you can also try noise under a Nova playlist at a lower level.
Can you mix noise with music?
Yes. Some people like a quiet layer of pink or brown noise under a lyric-free playlist, which covers room sounds while the music sets the mood. Keep the music a little quieter than you would alone, and keep the combined level low. If you catch yourself adjusting the mix instead of working, go back to one sound. See how to study with music for more.
Is white noise bad for you?
Hearing guidance is about volume and listening time, not the colour of the noise: according to the NIDCD, sounds at or below 70 dBA are unlikely to cause hearing loss even after long exposure, while long or repeated exposure at 85 dBA or more can. Nigg et al. also flag that the ideal volume for focus is unknown and that sustained exposure to even moderate levels can harm hearing.
Practical rules:
- Just loud enough to cover the room. You should still hear someone speaking at normal volume next to you.
- Take breaks from headphones between sessions.
- Do not raise the volume over time to “feel it more”. Turn it down if your ears feel tired.
The short version
White, pink and brown noise are the same idea with different amounts of bass. The research covers white and pink noise, shows a small effect for some people and none or a negative one for others, and has not tested brown noise at all. Listen to each on the sounds page, keep the volume low, and let a week of sessions decide. For the ADHD angle in more detail, read brown noise and ADHD focus.