Yeah i ve had spikes out of nowhere too, and im almost sure my T stayed up after one of them but i eventually habituated. And i've had temporary spikes from loud noises too but they eventually settled down within a few hours or a day or two like you said. One of the worst ones i had was when i was driving with my t-top off on the freeway, not sure if it was the air or the noise but once i got to a stop light i was like "oh fuck what have i done". The spike im currently experiencing is the highest its been and its like a fucking whistle!
Anyway, sorry to talk your ears off but i cant really talk to other people about this because they're just so clueless and start asking dumb stuff. Even the docs, but you already know this. One of the most annoying things is when people still ask me "have your ears got better" after i have told them numerous time "no, and they're not going to but i just deal with it". Anyway, just wanted to ask because i've heard tinnitus form loud noise exposure is usually permanent and from what i remember you said yours was from just that. I'm just so fucking lost and befuddled when it comes to this damn thing.