I have been having this issue for a couple years now, even running the newest version of parallels with my windows 7. I had the issue with yosemite and now with el capitan OS X.
Do you have a fix for this yet? It is extremely unprofessional when my computer randomly goes burzurk and crackles and sounds like a machine gun, and this will go on for minutes sometimes...It happens randomly, when my volume is on it can be extremely loud and very is unprofessional.
What is the fix?