Brown noise

What brown noise sounds like

Brown noise is a deep, soft rumble. Think of a far waterfall, strong wind outside a window, or the hum inside a plane. Most of its sound sits in the low pitches. The bright hiss of white noise is almost gone, so it feels warm and round, not sharp.

The name has nothing to do with the color. It comes from Brownian motion, the random drift of tiny particles in water, named after the scientist Robert Brown. Brown noise follows the same math: each moment moves a little away from the last one, so the sound rolls instead of crackling.

How it differs from pink, green and white

Brown noise is the darkest of the four. It gets about 6 dB quieter with each step up in pitch (each octave). Pink noise drops only 3 dB per step, so it sounds lighter, more like rain. Green noise brings the middle pitches forward, and white noise is an even hiss with the most treble.

When people use it

People play brown noise to cover low, steady sounds that come through walls and windows: traffic, a neighbor’s TV, a snoring partner, a humming fridge or air conditioner. Some keep it on at bedtime, others as a quiet background for reading or work. One tip: phone speakers can’t play the lowest pitches, so brown noise sounds thin on them. Headphones or a bigger speaker bring back the rumble.

Other colors