Similar experience. I'm in my 80's and worked for over forty years at Newark Airport, so my hearing wasn't great,but not too bad. About 3 years ago I was at a trap range and the instructor was saying something to me and I couldn't make out what it was. At that time I was using my old airline ear muffs which worked pretty good.. So I broke the seal on the left earpiece and one or two shots went off next to me. I didn't notice anything wrong til the next day.
Had the ringing (tinitus) and it sounded like people were mumbling and I had difficulty making out what they were saying.. The ringing was moderately bad and it lasted for about three months and then finally went away.
So, if you aren't having trouble understanding what people are saying, you should be all right.
Unfortunately for me I still have trouble making out what some people are saying. Apparently, I blew out all those fine little hairs in my left ear, so if people aren't speaking clearly,or mumbling or swallowing their words I usually get one word out of three. Had to get hearing aids but they are mostly just amplifiers and really don't help with speech clarity, no matter what anyone says..
All the best... Sounds like you should be OK
Kenny