I’ve had the same issue a couple of times. When it happens, I turn the volume down to zero to stop the noise, so I reckon it’s something like the sound card hardware and driver not working together properly. Mine went away after a reboot or two. Then it happened again and was fixed after another reboot. I had Autohotkey installed throughout, so I don’t know if that’s causing it or not, but it seems to be working most of the time.
