What brown noise is (and why it's different from white)
White noise contains every frequency at equal energy — it sounds like a hiss, similar to an untuned TV. Brown noise (also called red noise) drops energy by 6 dB per octave, meaning lower frequencies are far louder than higher ones. The result is a deep, rumbling sound — closer to a distant waterfall or strong wind — that most people find much easier to listen to for hours than white noise.
Why people use brown noise for sleep
Brown noise's low-frequency emphasis masks the abrupt sounds that wake you — a door closing, a car outside, a partner's snoring — without the harsh hiss that keeps your brain alert. Many people who can't tolerate white noise sleep fine to brown. It also masks tinnitus better than silence for some listeners, because the low-end energy overlaps with the sensation rather than fighting it.
Why it's good for focus too
Brown noise is uneventful — there are no transients, no surprises, nothing for your brain to track. That makes it a strong background for deep work, especially in an open office or cafe. White noise tires people faster because the high-frequency energy still triggers attention. Brown is, for most listeners, the calmest of the noise colours.
How this generator works
The noise is generated live in your browser using the Web Audio API — there is no audio file, no streaming, no loop point. Each sample is produced from the previous one via a random walk (the integration of white noise), which is the mathematical definition of brown noise. The audio runs entirely on your device and works offline once the page is loaded.