I got ringing at a concert a couple of weeks ago, it went away by morning and usually does. I used to get that all the time when I played in a band, most musicians these days wear ear plugs and now I do to, even sometimes at shows when I am thinking in advance.
It's very bad for your long term hearing to expose yourself to that. Don't want to end up with tinnitis then the ringing comes on at random times with no exposure or any ther triggers and they can't do much about it.
The military takes a large dose of antioxidants after shooting cannons and stuff, it is supposed to reduce the chances of long term damage.