Strange symptoms lately

This particular symptom appeared a long time ago; it didn't bother me much before, but now I'm thinking about it. Basically, because of the war, attack drones often fly near my house. And that was a couple of years ago, after a major drone attack, for about an hour or so, even in complete silence, I could still hear their engine hum, like a far, far away sound from a closed window. Although they're gone now. Then recently, when I was already in an anxiety disorder, something unusual for me scared me. I was lying down and taking my blood pressure (I take it twice a day because I need to monitor it), while watching something with one earphone on. It pumped up a certain amount (an electric blood pressure gauge), then started pumping more (which also happens often), but I was surprised that the engine noise lasted so long while pumping. I thought it had reached 300, but I looked and it showed 100 and then dropped further. It turns out there was no sound, but my brain thought there was and it was quite noticeable, even though I was listening to a video in the first earbud. Considering my recent fear of schizophrenia that developed about two months ago, this is even more frightening. Has anyone else experienced something similar, where there seems to be no sound, but due to the brain's expectations, there's still some sound?