Pink noise vs brown noise

Both gentler than white — the question is how much treble you want left. Switch between them below and keep whichever you stop noticing first — that is the one that is working.

Pink noise Generated live in your browser

Tap a second sound to layer it — rain under brown noise, for instance.

Side by side

Pink noise Brown noise
SpectrumFalls 3 dB per octaveFalls 6 dB per octave
Sounds likeSteady rain, wind in leavesA distant waterfall, a plane cabin
Masks bestA balance of high and lowLow-frequency rumble
ResearchThe colour most studied for sleepLittle direct research
Choose it ifYou want something natural and openYou want the deepest, calmest option

The short version

These two are far closer to each other than either is to white noise, and most people who like one will get along with the other. Pink keeps more of the treble, so it reads as rain; brown removes most of it, so it reads as a rumble. Pink has more research attached to it, but the studies that made it famous timed short bursts to brainwaves in a lab, which is not what happens when you play it steadily all night.

Questions

Is pink or brown noise better for deep sleep?

Pink noise has more research behind it, but that research used lab equipment to time bursts of sound to slow brainwaves — a different intervention from playing it continuously. There is no good evidence that either colour beats the other when simply left running. Comfort over eight hours is the more useful test, and that is personal.

Which is closer to rain?

Pink noise. Steady rainfall has roughly a pink spectrum, falling about 3 decibels per octave. Brown noise sounds more like heavy rain heard from indoors with the treble removed, or a waterfall at a distance.

Can I switch between them?

Yes, and it is worth doing. Use the player above, give each a few nights, and keep whichever you stop noticing sooner. Not noticing it is the point.

Every colour of noise

Beyond the colours

Not noise colours in the strict sense, but built from them — and useful for the same reason.