The problem with hearing damage is that it's unpredictable.
I shot for years without protection and we used to laugh about our ears ringing. Stupid, I know. Now.
I would have told you all those years that I didn't suffer any damage, I could hear fine.... but I was wrong. I worked briefly for a woman selling hearing aides. Got my ears tested. I suffer from high-frequency hearing loss. I was only in my late 20s at the time. I never did anything else particularly loud, not work, not music. Nothing but guns. I learned then that when I thought people were mumbling or I could not hear well in large crowds, it wasn't mumbling or crowd noise. It was hearing loss.
Then, just last year or the year before, after many years of always wearing ear plugs, I fired my Encore Pro Hunter. I had ear plugs in but the right side had apparently not sealed. My ear started ringing. It actually sort of hurt. No big deal, I thought, I've had ringing ears before. It'll go away in a day or two.... except it didn't... and still hasn't.
So, yes. A single shot can hurt. Especially from a really loud gun. A distinction for which most any hang gun would qualify.