Brown, pink and white noise

Press play on one layer to start. The button on each layer turns it on or off, and its slider sets how much of it you hear, so two or three can run together in whatever balance you like. A common starting point is brown noise on its own at a low level, with a little pink added if it feels too muffled. The master slider then sets the volume of everything at once.

Blending layers

Each layer is a different slope across the frequency range. Brown is heavily weighted to the bass, pink sits in the middle, and white spreads energy evenly, which our ears read as bright and hissy. Mixing brown with a small amount of white gives you the low bed plus enough high end to cover voices, which is usually what an open-plan office needs.

Setting a stop time

Pick 15, 30 or 60 minutes if the noise is there for a work block or a nap, and the mix fades out over the last 10 seconds rather than cutting off. Choose until stopped for anything open-ended. Changing the choice while noise is playing restarts the countdown from that moment.

Volume and your ears

Noise is meant to sit under what you are doing. Turn it up only until the sounds you were trying to escape stop pulling at you, then leave it there. Hours of listening at a high level through headphones carries the same hearing risk as anything else played that loudly, and the point of masking does not require volume.

The reliable part is masking. Broadband noise raises the floor of what you hear, so a conversation two desks away, a door, or traffic no longer stands out sharply against silence. Your attention is pulled by change and contrast, and noise reduces both. That is an acoustic effect, and it holds regardless of what you believe about it.

The claim that noise improves cognition is much weaker. Studies point in different directions, effects are small, and several find that continuous noise helps some people while it costs others, with results varying by task and by baseline attention. Brown noise in particular has a large following in the ADHD community, and many people report it helps them settle. Those reports are worth taking seriously as preference, but they are not the same as evidence that a particular sound tunes your brain.

So treat this as a masking tool and a matter of taste. If it makes a noisy room workable or gives you a consistent audio cue that work is starting, it is doing its job. If you find it irritating or it makes reading harder, that is a real result too, and silence or earplugs may serve you better.

Why there is no rain, cafe or fireplace

Those are recordings, and a recording has to come from somewhere and be licensed. Every sound here is calculated from a random number generator in your browser, which is why the page has no audio files, no third-party player and nothing to load. It also means the noise never repeats in an obvious way. Synthesised rain and fire exist as techniques, but they end up sounding like filtered noise with a wobble on it, so the honest version is the noise itself.