This is essentially what I do. I've had it tinnitus for some 20 years now. Both ears, a constant high pitched ringing.
Most of the time I honestly don't notice it, even in quiet rooms. As soon as something reminds me about it, or I'm trying to listen for something quiet, or certain high pitch sounds go off (my least favourite is flashbang like effects on TV or in games), it'll come back with a vengeance. So e.g right now because I saw this HN post, it's feeling especially loud.
It'll probably be about an hour before I'll forget to think about it (for want of a better description), and I go back to not noticing it.