I have no idea how it happened.
After updating to 10.3.8 and downloading the latest version of Skype, my mike is constantly on. So I get nasty feedback loops and all that ****. In addition to that, I have semi periodic noise sounds.
When I'm logged off, everything is fine. It starts when I'm logged in and no apps are running. I don't see any apps running in Activity Monitor either. Any help?