Brown Noise

Where the name comes from

Brown noise is named after the botanist Robert Brown, not the colour. He described Brownian motion — the random walk of pollen grains in water — and brown noise is the audio equivalent of that random walk: each sample drifts from the last instead of jumping independently. The result is a spectrum that falls away at roughly 6 dB per octave, twice as steeply as pink noise.

Practically, that means almost all the energy sits at the bottom of the spectrum. The bright hiss that defines white noise is simply not there. What you get instead is a broad, heavy rumble: a waterfall heard from a distance, the roar inside an aircraft cabin, heavy rain on a roof with the detail smoothed off.

Why it suits long sessions

Because so little energy lands in the frequency range where human hearing is most sensitive, brown noise can be played at a level that genuinely covers a room without becoming tiring. That combination — high masking, low fatigue — is why it has become the default for people who keep a noise floor running for several hours at a time.

It has picked up a following among people with ADHD, who often describe it as putting a lid on internal chatter as much as external noise. The research here is thin and mostly anecdotal, so treat it as something worth trying rather than something proven — but it costs nothing to test for a session and see whether it helps you.

Getting the level right

Brown noise hides in a room in a way brighter noise does not, which makes it easy to creep the volume up without noticing. Set it while the room is quiet, not during a noisy moment, and aim for a level where you stop hearing it as a sound and start experiencing it as a room that feels closed. If you find it too dark, pink noise sits between brown and white; if you want it even deeper, try red noise or the near-silent drift of black noise.