What is brown noise?
Brown noise is random noise whose power falls by 6 decibels for every octave you go up. In practice that means the low frequencies are strong and the high ones fade away, so instead of the hiss of white noise you hear a smooth, warm rumble. Scientists also call it Brownian noise or red noise.
The name has nothing to do with the color. It honors Robert Brown, the Scottish botanist who in 1827 described the jittery random motion of particles in water, now called Brownian motion. If you trace that motion over time and play it as sound, you get brown noise. That is also how it is made here: each new sample is the previous one plus a small random step, a so-called random walk.
What does brown noise sound like?
Think of heavy rain heard from indoors, a strong river, the roar inside a plane at cruising altitude, or the low hum of a big ventilation system. It is the deepest of the common noise colors. Many people describe it as enveloping or cozy, and find it easier to listen to for hours than white noise, which can feel sharp.
Because there is so little treble, brown noise is gentle on the ears at the same loudness. That is a big reason it became popular online for sleep and concentration from 2022 onward.
Make it deeper or lighter
- Drag Tone toward Darker for an even deeper, bassier rumble, closer to a distant storm.
- Drag Tone toward Brighter, or add a little pink noise, if it feels muffled and you want it to cover voices better.
- Turn on Gentle swell for a slow rise and fall, like breathing surf.
- Try the Deep sleep quick mix: brown noise with soft rain on top.
- Laptop or phone speakers cannot reproduce deep bass, so brown noise sounds thin on them. Headphones or a proper speaker make a big difference.
Brown noise vs white and pink noise
| White | Pink | Brown | |
|---|---|---|---|
| Power per octave | Rises 3 dB | Equal | Falls 3 dB |
| Power per frequency | Equal | Falls 3 dB per octave | Falls 6 dB per octave |
| Character | Bright hiss | Balanced, like rain | Deep rumble |
| Masks best | Voices, sharp sounds | A bit of everything | Low traffic, engines, bass |
| Harshness at the same level | Highest | Medium | Lowest |
The honest answer to “which is best?” is personal. If high sounds such as voices or a TV keep you up, white or pink covers them better. If low sounds such as traffic or a neighbor’s music bother you, or you simply find hiss irritating, brown is usually the pick. See white, pink or brown noise for sleep for a fuller comparison.
Is brown noise good for sleep, focus and ADHD?
Brown noise works for sleep in the same way as any steady noise: it covers sudden sounds so they are less likely to wake you. Its low, smooth character makes it comfortable to leave on all night.
For focus, many people with ADHD report that brown noise quiets their mind. There is research showing that background noise can help some people with attention difficulties, mostly using white noise, but very little that tests brown noise directly. We summarize what is actually known on the brown noise for ADHD page and in does brown noise help ADHD?.
Why this brown noise does not loop
Most brown noise videos and apps play a recording of a few minutes or hours on repeat. With brown noise, loops are especially easy to notice, because a slow random walk can wander into a distinctive swell that comes back each time. Here the noise is computed live, one sample at a time, so it never repeats. If you need it offline, the download button makes a file whose end is crossfaded into its start, so even the loop is seamless.
Frequently asked questions
Why is it called brown noise?
It is named after the botanist Robert Brown, who described Brownian motion, the random jiggling of particles in a fluid. Brown noise is what that random walk sounds like. It is not named after the color, although people often picture it as warm and brown.
Is brown noise better than white noise for sleep?
Many people find it more comfortable because it is deep and soft, while white noise can sound harsh. White noise is better at covering high-pitched sounds such as voices. Try both at a low volume and keep the one you stop noticing first.
Is it safe to listen to brown noise all night?
At a quiet, comfortable level, yes for most adults. Keep it below the volume of normal conversation and well away from a baby’s crib. Use the sleep timer if you would rather it stopped after you fall asleep.
Why does brown noise sound different on my phone?
Small speakers cannot play deep bass, and most of brown noise’s energy is in the bass, so a phone speaker plays only its upper edge. Headphones, earbuds or a larger speaker reproduce the full rumble.
What is the difference between brown noise and red noise?
None. Red noise is another name for the same 1/f-squared spectrum, used especially in science and engineering. Brownian noise is a third name.