how do speakers break?

I've been freaking out a bit lately as we approach the online broadcast of The Bonapartes' appearance on UMCP's radio station, listen here tonight at 6 p.m. EDT. I was afraid I wouldn't be able to hear it because I thought my soundcard was dying. With the volume all the way up, only a pathetically low sound comes out of my speakers. I reinstalled the drivers and that didn't make a difference. Then it occured to me to try headphones. Guess what, I turned them on and it was plenty loud! So tell me, how do your integrated laptop speakers just die like that?

I still hope I can get an archive of the show to listen whenever I want, but now I don't have to strain to hear anything.