Interesting how much of this I'd already figured out just by experimenting on myself. I definitely did not rule out tinnitus (and I had a pretty bad case of that at some point in the past, which totally ruined listening to violin music for me, but fortunately it has since reduced to the point of not being noticeable, maybe this is some kind of remnant).

Anyway, I think of it as an interesting phenomenon, it doesn't bother me much (except when trying to fall asleep, once I notice it it is impossible to stop noticing it).