not hearing media sound

I am having problems not hearing the media sounds, and I have the latest version of QuickTime as that just did an update. I was trying to stop some of my lag problems with a note card received from a friend and I think I have messed my settings up some how, so is there a way to set them back to their default settings. Is there something I should do to QuickTime to make that my default program to make it work for me in Second Life? Right now I am re-enstalling the game but I dont hold any hopes of that helping me much.

oh yeah it wasnt muted either