Man I hate stuff like that. I have tinnitus so there's always a symphony going on in my head, but I'm used to it so when something new comes along, it gets my attention.
My full vote goes toward alien chip activation. I've told my wife for years I think I have one. Every now and then it goes off with a crystal clear dinging sound. Kind of like the keys in ignition but door is open but much higher frequency.
I call it my stress meter. Usually happens when the kids get themselves in trouble. My dinger goes off. lol
I think if I was in bed with my wife, and I heard a humming it would be for a whole different reason.
