I came across this link to an article on The Guardian via Justin Blanton’s blog, and got a kick out of it. Emma Beddington wrote back in October:
There’s a new buzz on TikTok – well, not a buzz exactly. It’s more of a hum, maybe waves crashing, a purring fan or steady, heavy rain. To me, it sounds like an empty aeroplane, cruising peacefully at altitude. It’s brown noise, a close cousin of the better-known white noise, and TikTok users, particularly the platform’s ADHD community, are all over it: there are 85.3m views for the #brownnoise hashtag.
The “brown” in brown noise is not a colour, but a reference to sound that mimics Brownian motion, the movement pollen makes in water, identified by the botanist Robert Brown in 1827. In essence, brown noise is the familiar, staticky sound of white noise (that is, all the audible frequencies simultaneously) but with the low frequency notes augmented and the less pleasant high frequency notes turned down, counteracting the human ear’s natural tendency to hear higher frequencies louder.
Like Justin, I’m a huge fan of brown noise, using it often as I fall asleep. I usually mix in a little “rain” noise for the perfect sleepy-time sound via the excellent Dark Noise.