I can't trace back exactly what seems to have caused this to happen on my captivate, but I was on hold and I put my phone on speaker, but I couldn't hear anything when I did that. So I turned speaker off and I could hear the music again. After hanging up the call though, I'm unable to get any sound out of anything on the phone. It doesn't ring, it doesn't make any notification sounds or anything. I've checked my settings and all of the volumes are on. I started a call with another phone to experiment, and after muting the call I was able to get some sound on the phone app, but after hanging up I still get nothing. I've restarted the phone, and it makes no sound when turning it on either. Thank you for any help.