How exactly would they infer you are recording them from the fact you are being quiet?

You don't think they are recording you when they go quiet, so neither should they. That is not a logical thing to think.

Maybe Pfrog is right that the best thing to do is get out of there, even temporarily although I understand that might not be practical for you.

My concern is though, that there is an element of psychosis to this & even if you did move, you'd hear loud noises & think someone else had started up. Even though I've not said it recently, I still think you need to talk this over with your p-doc because there have been elements of it that are symptomatic.

Sure, maybe the noise is triggering, but that means your meds aren't working properly.