Why brown noise sounds so deep
Brown noise loses energy quickly as pitch goes up: 6 dB every octave. Almost all of it sits in the bass, which is why it feels warm and enveloping instead of hissy. It's also called red noise.
The name has nothing to do with the color. It comes from Robert Brown, the botanist who described Brownian motion, the random jiggling of particles that this kind of noise imitates.
Brown noise for sleep
Low, constant sounds like traffic, a fridge or a partner's snoring are hard to block with earplugs. Brown noise covers that low range well, and because it has so little hiss, many people find it the easiest noise to fall asleep to.
Prefer something with a little texture? Try Rain & Thunder, which layers rain over a brown-noise bed.
Brown noise and ADHD
Brown noise went viral with people who have ADHD, who say it quiets a busy mind. Brown noise itself hasn't been studied much yet. The closest research (Söderlund et al., Journal of Child Psychology and Psychiatry, 2007) used white noise and found it helped children with ADHD on a memory task while slightly hurting other children, so the effect seems to depend on the person.
How to use brown noise
- Play it through a speaker with decent bass; tiny phone speakers lose the low end.
- Set the volume just loud enough to blur the room's sounds.
- Choose Auto-stop: 1 hour to fall asleep, or up to 8 hours to sleep through.
- For focus, keep it in the background at a lower volume.