Linux Mint Forums

I have had this issue when running KDE in general. There are settings in the volume control applet, I think that you need to turn off the mic volume(mute it), regardless of if there is a mic connected or not, this solved the issue for me. Also try adjusting the pcm, and master volumes to see if it helps with the noise.

edit: k-sound i think is the applet's right name, (I'm a gnome guy mostly, I just tinker with KDE)

It is normally the PCM volume that has to be made 100% to get sound working again.
some how it gets lowered or set to 0 and sound is gone.

Boo

if it's happeneing in all distros, and all WM's, then I think that is an issue with your sound card. I wish I could help more, but that is all I can think that it could be. Good luck.