I sleep talk everyday. I tried to search for ways to stop it but they were all useless. It's very embarrassing that my mom hears it but she refuses to tell me what I've said. I'm embarrassed to sleep when anyone is around. Is it normal that I sleep talk when I'm a teenager? And if you have ways to prevent it, please write it down in a comment.

Then you will only have your talking on the recording and won't have to listen through hours of silence to find out what you said.
Unfortunately, all my attempts to interrogate his subconscious have failed :(
I used to talk in my sleep, using a bunch of diffirent languages, and even though I never said anything bad it still freaked people out.
What I did notice -it didn't happen every night, just the nights when my mind was racing, when I was stressed... in general, when there was more brain activity going on than there should be.
So the answer for me was just meditating and relaxing before I go to bed, instead of studying or watching stuff.
Hope it helps! :)