My A/V setup goes through a 5 port switch and then into a 4 port splitter I just upgraded to. Something was wrong and using the splitter was giving me really messed up glitch audio.
I initially thought maybe the new splitter was bad, but I took it out of the chain and confirmed it's fine on other sources. Then, I took the switch out and confirmed it worked fine in conjunction with the splitter. This left me pretty confused since I was getting the audio out of multiple devices, meaning I had already ruled out the cable.
Unsure what to try next, I just put it back in the setup, plugged all the sources in and started adding the outputs. First I went with the TV, no issue. Projector, not a problem. Capture card, still going great. Finally I plug the computer monitor in and get the buzzing back.
Hoping for the fix that requires me doing less cable management, I move it to the other HDMI port on the monitor and it's fixed. Just for fun I decided to switch it back and it's still fixed.
In Summary there was a ghost trapped in one of my HDMI cables and I had to unplug it to let them out.