If I'm not listening to music or hyperfocusing really hard there's a constant looping snippet of some random song playing almost all the time, usually just a few seconds long. Changing it requires to listen to something else. I don't really mind it (as long as the song doesn't suck!), seems like my brain just needs a constant rhythm throughout the day. I always thought that it's normal for everyone until I learned about neuro divergence a year ago.