Well, I thought I had seen just about everything…until Bat-Man checked in!
He was probably in his 70s and un-married, a retired engineer he said. He walked up to the desk to check in, and when I looked up I almost lost it. He had these clear plastic bat-wings sticking out of the sides of his head.

Earglasses made of clear plastic
He said he likes them, but knows that they make him look more than a little odd. He has regular electronic hearing aids for more formal situations, and uses his Earglasses mostly in private.
Bat-Man was a perfectly well behaved guest, and we wished him well when he checked out two days later.