Try moving the speaker cables away from the rest of your cables (eg. Monitor, Mouse, Keyboard, Power, etc)
I find that i get some static noise that seems to go with what is not my display, mouse movement or keyboard strokes.
However, as soon as I untangle the "cable farm" that is behind my PCs and make sure that there is some space between the speaker cables and everything else, i don't get the feed back.
I hope this works.
"I FEEL SO GOOD I FEEL SO NUMB, YEAH!!!" -- Rob Zombie
Main Rig - AMD FX-8350x8 4.0Ghz CPU, 4x 8Gb (32Gb) DDR3 Ram, Gigabyte GA-970A-D3, GeForce GT 970 4Gb, 1x 256Gb SSD\8Tb (3+2+2+1) SATA HDD, DVDRW, SB X-Fi, Win 10 (64-bit)
Asus N61JV-JX231V - Intel Core i5 3437u (1.9 - 2.4 GHz), 12GB, 640GB, 16" Display, nVidia 325M 1Gb, DVD-RW, Win 10 (64-bit)
Mobile Phone : Samsung Galaxy 5 Note SM-N920IConsole : Play Station 4