Brown noise
Deep and low, like a distant waterfall. The most popular colour for sleeping.
Layers — mix as many as you like
Tap a second sound to layer it — rain under brown noise, for instance.
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What is brown noise?
Brown noise loses 6 decibels for every octave you climb, so nearly all of its energy sits in the low end. It sounds less like static and more like a waterfall in the next valley, or the cabin of an aircraft at altitude. Of all the colours it is usually the easiest to tolerate for a full night, which is why it has overtaken white noise as the popular choice for sleeping rather than just for masking.
Red noise is another name for the same thing — identical spectrum, different label.
This page is a brown noise generator: the sound is computed in your browser rather than streamed from a file, so it starts instantly and never reaches a loop point. More on how that works.
Good for
- Full-night listening, where brighter colours start to grate
- Low-frequency masking: traffic rumble, machinery, footsteps overhead
- People who find white noise too sharp
The details
- Spectrum
- Falls 6 dB per octave
- Also called
- Red noise — the same thing, different name
- Sounds like
- A distant waterfall, a plane cabin, heavy rain without the patter
- Named after
- Robert Brown, not the colour — see below
Questions
Is brown noise the same as red noise?
Yes. They are two names for an identical spectrum that falls 6 decibels per octave. "Red" fits the pattern of the other colour names, where red light sits at the low-frequency end of the visible spectrum. "Brown" is the more common name in sleep contexts and comes from a different source entirely.
Why is it called brown noise?
Not after the colour. It is named after Robert Brown, the botanist who described Brownian motion — the random jittering of particles suspended in fluid. The mathematics that generates this noise is the same random walk, so his name attached to it and stuck.
Is brown noise better than white noise for sleep?
Better is personal, but the popularity gap has a reason. Brown noise concentrates its energy where the ear is less sensitive, so it stays comfortable across eight hours where white noise can begin to feel sharp. White noise still masks more of the higher-pitched sounds, such as voices and birdsong. Choose by what is keeping you awake — see the comparison.
Every colour of noise
White noise
Equal power at every frequency — the bright hiss that masks almost anything.
Play white noise →Green noise
Mid-range noise, often described as the background sound of open countryside.
Play green noise →Pink noise
The middle ground: softer than white, brighter than brown. Close to steady rain.
Play pink noise →Blue noise
The mirror of pink: energy rises with pitch, giving a bright, airy hiss.
Play blue noise →Grey noise
Shaped so every frequency sounds equally loud, rather than measuring equally loud.
Play grey noise →Violet noise
The mirror of brown: rises 6 dB per octave into a thin, piercing hiss.
Play violet noise →Black noise
Effectively silence, with almost all energy below what you can hear.
Play black noise →Beyond the colours
Not noise colours in the strict sense, but built from them — and useful for the same reason.
Rain
Steady rainfall with the patter on top — the most requested sleep sound there is.
Play rain →Fan
A box fan running in the corner, without the draught or the electricity bill.
Play fan →Ocean
Slow waves arriving and drawing back, roughly ten to a minute.
Play ocean →Thunderstorm
Rain with distant thunder rolling through at irregular intervals.
Play thunderstorm →