Brown noise

Brown noise is the deep end of the noise family: its energy quarters with every octave — about −6 dB per octave — so almost everything you hear sits in the low frequencies. The result is a soft rumble, like distant thunder that never arrives, heavy rain on a roof, or the cabin hum of a long flight. The player below starts with pure brown; add a little pink if you want the midrange filled back in.

Press play for pure brown noise — a leaky integrator over random samples, generated live. A touch of pink on top fills in the middle.

White 0%

Pink 0%

Brown 85%

Volume 80%

Sleep timer

No timer set — playback continues until you pause it. With a timer, the sound fades out gradually at the end instead of cutting off.

Volume first: brown noise's energy is concentrated in the bass, which is easy to underestimate on small speakers and easy to overdo on headphones. Start low; if you can feel it more than hear it, it is probably too loud for all-night listening.

What "brown" means: −6 dB per octave

Idealised spectra. Above its low-frequency corner, brown noise falls about 6 dB per octave — each octave carries a quarter of the power of the one below it.

The name has nothing to do with color: it comes from Brownian motion, the random walk Robert Brown watched under a microscope. Mathematically, brown noise is the integral of white noise — each sample is the running total of all the randomness before it — and integration is exactly what tilts the spectrum so steeply: −6.02 dB per octave, a quarter of the power each time the frequency doubles. In this player the integration is done by a leaky integrator (each step keeps 98% of the accumulated value), which is the standard practical form: it keeps the deep character while stopping the signal from wandering off and clipping. One honest consequence: toward the very bottom of the spectrum the leak flattens the slope out progressively — the idealised line in the diagram keeps falling, the real generator gently levels off through the lowest octaves, which your ears will never notice.

We verified the generator offline at 44.1 kHz: across the octave bands from 250 Hz to 8 kHz the measured slope sits at about −6 dB per octave, as the definition requires. Like every color here, it is RMS-matched to the same level (0.22) as white and pink, so its reputation for sounding "stronger" is about where the energy lives, not how much of it there is.

When people choose brown

Brown is the most popular color for sleep and for blocking low, droning intrusions — traffic rumble, a neighbour's bass, aircraft and HVAC hum — because it puts its masking energy in the same range. Many people also say it feels calming or helps them concentrate; those are personal reports, not medical findings, and we present them that way. If brown alone feels like a sealed room, the classic blend is brown underneath with 20–30% pink on top — the homepage mixer starts there.

Questions

Is brown noise the same as "deep" or "dark" noise on other apps?: Usually, yes in spirit: most "deep noise" sounds are brown or brown-like low-passed noise. True brown noise has the specific −6 dB/octave definition described above.
Why is it called brown if it is not a color?: It is named after Robert Brown and Brownian motion — the random walk the signal performs. White and pink borrowed color names from light; brown kept its discoverer's name instead.
Does brown noise help with ADHD or anxiety?: Some people with ADHD say steady low noise helps them settle, and you will find plenty of testimonials. Controlled evidence for brown noise specifically is thin, and this site makes no medical claims — if it helps you focus, use it; if you need support, see a clinician.
Can I download this as a file?: Yes — the export button renders a 60-second WAV of the current mix in your browser, from the same leaky-integrator generator the player uses.