I know its hard to believe, but you can actually get a virus inside of your speakers, that could be one option.
But then again it could also be, you have a cellphone or something that interferes with the frenquency of your speakers and causes the noise,
and it could be loose cords, or wiring, etc.
I had this problem before, my case was I had a legit virus in my speakers, so I had to get new ones, common problems after getting my speakers fixed with the noise was due to the fact my cellphone was on the computer desk, but if I had it away from the computer it would work fine.