Computer speakers receive interference
Opening in computer case
This issue is caused when there is an opening in your case allows wireless signals to enter or be trapped within a computer. Make sure all drive bays are covered and that all expansion slots on the back of the computer that are not being used are covered.
The placement of the computer could cause it to pickup interference. If possible, adjust or move the computer to an alternate location. For example, try moving the computer to the floor instead of on top of a desk.
Again, the placement of such a peripheral or wiring to a peripheral could cause interference. If your speakers are on top of a desk or shelf, move the speakers to an alternate location.
It is also possible that the speakers themselves could also have issues with wiring or the actual EMI shields within the speakers. Consider trying an alternate pair of speakers.