Brown Noise

Why it sounds like that

Brown noise falls about 6 decibels per octave — twice the slope of pink — so by the time you reach the top of your hearing there is almost nothing left. What remains is the low end: a rumble somewhere between distant surf, a waterfall and an aircraft cabin.

The name has nothing to do with the color. It comes from Brownian motion, the aimless jitter of a particle in a fluid, because the sound is generated the same way: each sample is the previous one plus a small random step. Wander at random and the result, heard as sound, is this.

What it is good against

Low-frequency noise is what brown noise masks best, and low-frequency noise is exactly what walls do not stop: traffic, a washing machine two rooms away, a fan, the bass through a shared wall. Against a nearby conversation it is much weaker than white or pink noise, because speech lives in the middle frequencies this one has quietened.

It also asks more of your speakers. Laptop and phone speakers cannot reproduce much below a few hundred hertz, so brown noise through them can sound thin or barely there — that is the speaker, not the sound. Headphones or anything with a real woofer make the difference obvious.

How it is made here

It is generated in your browser rather than downloaded: white noise integrated step by step, with a small leak so it cannot drift away from the center, then normalized so it never clips. The build measures the result in octave bands and confirms the slope, so a mistake in the generator would fail a check rather than quietly sounding wrong.

For something with waves rather than a steady rumble, Ocean Waves is a recording instead of generated noise.

What this page does not claim

It plays a sound. Brown noise has had a run of attention as a focus aid, and this page takes no position on that: no claim about concentration, sleep, tinnitus or anything medical. Try it, keep it quiet, and stop if it does not suit you.

White vs Pink vs Brown Noise explains how the three differ and what the research says.