Brown noise is the deepest of the three noise colors here, weighted so heavily toward the low end that it reads as a rumble rather than a hiss — closer to distant thunder, or a jet heard from far away, than to a hiss on a radio.
Where the name comes from
It has nothing to do with the color brown. It's named for Brownian motion, the random jittering of particles a botanist named Robert Brown once described — the noise-color names followed for consistency, and brown happened to land on the darkest-sounding one, a coincidence people have since read a meaning into. Some people find its weight easy to sit with for hours; others prefer something brighter. Try it next to green and white and see which suits you.
Listen safely
This is a sound, played back through whatever speaker or headphones you already own. It doesn't diagnose, measure, or promise anything about how you sleep, focus, or feel — it's just noise and a handful of real recordings, mixed the way you like them.
Keep the volume low enough that you'd still notice a smoke alarm, a phone ringing, or someone at the door. If you fall asleep in headphones, choose a volume and a pair you'd be comfortable wearing all night, and a session length that ends when you'd want the sound to stop.
If you use this near a baby, keep the speaker several feet from the crib, never inside or clipped to it, and keep the volume low — the same care you'd take with any sound machine in a nursery.
If your relationship with sound, or with sleep, feels difficult rather than simply restless, a doctor or audiologist is the right person to talk to. This is a mixer, not a clinician.
What makes brown noise different from white or green?
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Brown noise's energy falls off steeply as frequency rises, so almost all of what you hear sits in the low end — a deep rumble rather than a hiss. White noise spreads energy evenly across the whole range, and green noise sits somewhere in between, closer to the middle.
Why is it called brown noise if it isn't about a low pitch?
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The name is a pun, not a description of pitch. It comes from Brownian motion, the random jittering of particles that a Scottish botanist named Robert Brown first described — brown noise is the sound you get by running that kind of random walk through a speaker. The color naming (white, pink, brown) followed for consistency, and "brown" happened to land on the deepest, darkest-sounding member of the family, which is a coincidence people have since read a meaning into.
Is it the same as a bass-heavy recording of something real?
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No. It's built from mathematical noise in your browser, with no sample, loop, or field recording underneath it. It sounds bass-heavy because of how its frequencies are weighted, not because it started as a recording of thunder or an engine and had the highs removed.
Will it damage speakers or headphones at low volume?
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No — at the moderate volumes this mixer is designed for, brown noise is no harder on equipment than any other sound. Very loud, sustained bass through small speakers can stress them over time, which is true of any bass-heavy audio, not something specific to brown noise.
How loud should I set it?
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The same guidance as any background sound here: quiet enough that a normal conversation, a phone, or a smoke alarm would still cut through clearly.