Fanno
Brown noise is the deep one: a low, soft roar with most of the hiss taken out. Where white noise sounds like static, brown sounds more like a strong wind heard from indoors. This page explains what it is and how it sounds, in plain words, and plays it as the tone of a fan, live in your browser.
Brown noise, plainly
All three colours of noise are random sound spread across the pitches we can hear. What changes is the balance. White noise has the same energy at every frequency, so it’s bright. Pink noise falls by about 3 dB per octave, so it’s balanced. Brown noise falls about twice as fast, around 6 dB per octave, so the low end does most of the work: a rumble, with only a little air on top. Out in the world it’s close to distant thunder, heavy surf, or the steady roar inside an airplane cabin.
The name has nothing to do with the colour. It comes from Brownian motion, the random jiggle of tiny particles in water that the botanist Robert Brown described in the 1820s; brown noise follows the same kind of random drift. You’ll also see it called red noise. Our guide to white vs pink vs brown noise puts all three side by side.
Brown on Fanno’s fan
In Fanno, Brown is the deepest tone you can give a fan. The air’s high end is rolled far down and the low whoosh is pushed forward, so a box fan on Brown sounds like a big fan running across the room: all body, very little hiss. The blades still turn and the room is still there, and that gives the depth some shape. A plain brown noise can feel like a muffled rumble with nothing to hold on to; a fan on Brown has a soft pulse and air moving through it. Because Fanno makes it live, the rumble never loops. It’s also where the app starts: the box fan, on Brown, at speed 6.
When deep works best
Low sound is good at softening low noise. Traffic rumble, a neighbour’s bass through the floor, the thud of footsteps upstairs, a truck idling outside: these sit in the same range where Brown is strongest, so they blend in rather than stand out. It’s also the tone to try if White and Pink sound too hissy to you. Of everything in Fanno, it’s the closest to a big old fan in a quiet house.
Setting a deep fan
Brown changes a lot with speed. On the app’s dial, the low click-stops make it a quiet, far-off rumble; as you turn up toward 10, more air comes through on top and it grows into a full, deep roar. This page plays speed 6, near the middle. A few combinations worth trying in the app:
- Box fan on Brown: this page’s sound, the classic deep fan
- Ceiling fan on Brown: a slow, dark sweep from far overhead
- Air purifier on Brown: a low, smooth rush with no blade beat at all
If it ever sounds too muffled, press Pink on the strip to let a little more air in.
Keep it running with the app
On iPhone, a browser falls silent the moment the screen locks. For a whole night, the free Fanno app keeps Brown going after the phone locks, and the Lock Screen gets play and pause controls. Its sleep timer knob, with settings up to two hours, eases the fan out at the end rather than stopping dead. There’s night mode for a dark panel, and a Blade texture fader to bring the blades forward or smooth them into the rumble.
There are no ads and no account, Fanno collects no data, and it works offline on iPhone and iPad.