As a kid in Australia a fan.
As an adult, a fan plus tinnitus
I heard there was a website called only fans, you might be eeeeeeeeeeeeeeeeenterested
I was nearly always grounded from all electronics from 6-13 (autdhd, and authoritarian parents, bad mix), and had a bedroom with no exterior windows. My window went to a modified 3-season porch thing, in 2 of the 3 places (the third was an apartment for like 6mths, I barely remember it), and that’s where my mom slept, so… really quiet dead silence, mostly, else I was in trouble. Again. Or whatever garbage my mom had on tv, muffled through the wall.
Now I have tinnitus, so silence is really loud. I have aquariums tho and the hum and bubble of the air pump helps a lot (plus really loud circulation fans).
Hilary Duff CDs on loop. I felt like every song had something to relate too. Anytime I try to play them now and my friends tell be to turn it off.
Mostly nostalgia for me now. Remembering a time I had dreams.
Vin Scully(Dodgers), Dick Engberg(Angels, Rams), Chick Hearn (Lakers) and Jiggs McDonald(Kings) on my 9 volt transistor radio well hidden under the covers. So well hidden that it ended up switched off and in the drawer by morning.
Breeze, rustle of leaves, sounds from birds and insects. Fan if no breeze.
As a kid varius radio play cassettes like Benjamin Blümchen, Bibi Blocksberg, later the Star Wars soundtrack.
Nowadays various science shows on YouTube. Mainly astrophysics stuff. My favourites are Dr Becky, Harald Lesh and PBS Space Time.