This is the most bizzare thing I ever come across…
My computer is muting and unmuting itself. The behaviour is unpredictabl but occur in “spams”. For five minutes it will be all right, then for a while it will frantically mute/unmute itself.
It’s the same thing online / offline, soft reset or hard reset. I am using a Soundblaster Live! soundcard…
Do you have one of those annoying keyboards with the “multimedia” buttons? I do, and one of those buttons is the “mute” button. They’re soft rubber buttons up at the top of the keyboard, and can easily be pressed by accident. I had my keyboard wedged in a drawer once, and a bunch of those buttons were randomly getting pressed - you might want to check if something like that is happening.