White, Pink, Brown, Violet: The Colours of Noise, Explained by Ear
Short answer: Noise is every pitch at once, at random. The colour tells you which end is louder. White is equally loud everywhere and sounds like hiss. Pink gets quieter as it goes higher and sounds like steady rain. Brown falls away faster and sounds like a deep rumble. Violet is the reverse of brown: thin and sharp.
| Colour | Sounds like | Where the energy is | People use it for |
|---|---|---|---|
| White | TV static, an untuned radio | Spread evenly | Covering sharp, sudden noises |
| Pink | Steady rain, wind in trees | More at the bottom, falling gently | General background, covering voices |
| Brown | A big waterfall far away, a plane cabin | Mostly at the bottom | A low, soft cover that stays out of the way |
| Violet | A thin, sharp hiss, like steam | Mostly at the top | Technical uses. Not for listening. |
Why white noise sounds harsh
On paper white noise is the fair one: every frequency gets the same energy. But there are far more high frequencies than low ones, and our ears are sharpest in the upper-middle range. So it comes out bright and hissy, and many people find it tiring after a while.
Why pink sounds natural
Pink noise turns the high end down at a steady rate, and the result sounds even to most people. A lot of natural sound has roughly this shape, which is why pink noise gets compared to rain and wind.
Brown noise is not named after the colour
This one surprised me. White and pink are named by analogy with light. Brown is named after Robert Brown, the botanist behind Brownian motion, the random jitter of small particles in water. The signal wanders in the same way. It is also called red noise, which does fit the colour scheme.
Which one to use
- Voices nearby: pink or white. Speech is clearest in the middle and upper range, and brown noise has little energy there.
- A low rumble you can forget about: brown.
- Long sessions: pink or brown. White gets tiring.
One caution. A 2024 review found that white and pink noise helped task performance a little in young people with ADHD or attention problems, and made it slightly worse in those without. Brown noise had not been studied at all. So noise is good at covering other sounds. Whether it helps you focus depends on who is listening.
I haven't read the sleep research properly yet, so I'm not going to tell you which colour to sleep to.
What noise can't do
The first second of any noise colour sounds like the thousandth. That is its strength, because there is nothing to notice. It is also the limit, and some people find it heavy after a few hours. What I built is the other option: sound that keeps one steady mood, changes slowly and never repeats. I compared the two in Brown Noise vs Ambient Sound.
Sources
- Colors of noise, Wikipedia: the definitions and where the names come from
- Nigg and colleagues, 2024: review of white and pink noise and task performance
Try it: Ocean is free and starts in one click, with no account. Put it next to brown noise and see which one you can leave on longer.
Open Ocean, free