Is the hearing regenerative?

We were watching Harry Potter and the Chamber of Secrets in German lessons 2 days ago, I was sitting in the 2nd row which is about 1m away from the beamer case (the beamer case has: laptop, bluetooth speaker and beamer). We had the volume on the pc full and on the speaker 3 levels below the loudest level. After watching the movie I noticed that I heard everything much quieter. In the afternoon after school, I asked my mother, which nurse is and who said that in a few hours would have to give again, this did not, so I come now to the first question, which says whether the part is regenerative and 2. Did I read a report from a laboratory experiment, which is a pill that stopped protein production in mice and thus the hair cells could regenerate, also claimed the researchers in 2004 that in 2-4 years, a pill for deafness I will now formulate the second question: why is this pill not yet available? I'm just panicking because of that.

No panic. That settles again. Otherwise, all people who have ever been to a concert would be deaf. Sure, your ears may be a bit offended now, but in a few days at the latest, everything should be back to normal. And please do not stress too much in there. The psyche has a great effect on our physical condition (if you imagine that you are hearing badly, are you really hearing worse). And you will not be hard of hearing so.

Okay, thank you for this answer