Great! I can finally file for disability.
A guy from the utility company came by today and listened. He couldn't even hear it, but they sent a 60-year old with hearing aids and he didn't even have one of them.
I'm beginning to think it's an electronic device because it doesn't change in pitch and it doesn't stop. Maybe something is malfunctioning on my neighbor's back deck. I'm going to knock on his door tonight.
Old people can't hear high pitched things.
There used to be ringtones for teens that were outside the hearing range of their teachers (don't know how that is better than vibrate...but who knows).