So I'm 16 years old and I've had this problem since I was in 8th grade.
Basically, my hearing started to randomly become muffled. It lasted like maybe an hour and then it would go back to normal. This also happened in only one ear. Now, it's both of my ears and one goes in and out at a time. Right now it's my left ear and it sounds like someone shoved cotton down my ear canal.
Whenever I bite down on something, my hearing in my left ear worsens. Now it does not go back to normal and it takes up to 2 weeks to actually feel semi-okay. When I pull my earlobe down, I can hear somewhat clearly, but as soon as I let it go it goes muffled again.
I've cried over this, no it doesn't hurt, I cried because I finally get to do something I've been wanting to do for years! And this will just completely ruin everything.