So a couple days ago i noticed an annoying screeching/crackling sound coming from mainly the left two of my four speakers. At first I thought it was the speakers and that they had died and it was time to get new ones. I decided to unplug these two troublesome speakers from my sub woofer, but the screeching/crackling sound still persisted! it was now instead coming from my other two speakers. Naturally, I was dumbfounded. I then plugged some headphones directly into my computer, and what do you know! the crackling sound was in my headphones as well.

It isn't my headphones as it does not happen when i plug them into my ipod. I fear it may be my sound card or my drivers may be out of date. However, I'm still a bit of a linux noob so I do not know what to do or how to update my drivers or figure out the problem.

Thanks in advance for your help.

P.S. when i was on windows, my drivers were Sigma Tel, idk if that helps.