25 minute timer with brown noise
Brown noise is deeper than white or pink noise: it rolls off the high frequencies even harder, leaving a low, steady rumble like distant surf or a jet cabin at cruising altitude. On this page your browser synthesizes it on the spot, so there is no recording and no seam where a loop repeats. The timer runs the classic pattern: 25 minutes of focus, a 5-minute break, and a 15-minute long break after 4 rounds.
Many people with ADHD report preferring brown noise for focus, and it is the default sound on the ADHD and study timers for that reason. They describe the low rumble as something constant to rest against, without the hiss some find tiring in white noise, and it covers low sounds such as traffic, ventilation, and footsteps overhead.
Brown noise is a poor match for people who find bass fatiguing, or who work in audio and need fresh ears. It also masks less of the high end, so a colleague on a phone call may still cut through, and pink or white noise will do better there. It is not a treatment for anything, only a sound some people find easier to work beside.
Questions
why do people with ADHD like brown noise
Many say a low, constant sound gives their attention something to settle on, so small noises and stray thoughts stand out less. That is a common report, not a diagnosis or a treatment, and plenty of people with ADHD prefer silence or music instead.
how loud should brown noise be for focus
Low enough that you could still hear someone speak to you, the same rule as any background sound. The 5-minute breaks the timer gives you are a natural point to turn it down and let your ears rest.
what is the difference between brown noise and pink noise
Brown noise rolls off the high frequencies more steeply than pink noise. In practice brown sounds like a deep rumble with almost no hiss, while pink keeps some of the higher rain-on-a-roof texture. Brown covers low sounds better, pink covers voices better.