CS source has a buzzing noise/cracking noise

[Plague27]

For some reason, I had been playing cs:source fine, then all of a sudden, one day I turn it on and the game is doing this slight buzzing noise whenever a sound goes on and then cracks happen whenever someone shoots. I have plan of attack and it works fine, but cs is being stupid for some reason. I have audigy 2 zs, and I tried upgrading from the newest drivers to the newest beta drivers and it did not fix the problem. What should I do?

 

[short recoil]

stuttering, many, many people get this.......its partly to do with the engine itself.
I sometimes randomly get it and i have a really decent set up.
It is most annoying.

 

[Plague27]

I don't think it is stuttering.....it works fairly smooth, but this buzzing noise is making me want to cry.