I have two mysterious muscles, one in each ear, that I can contract at will. When I tense them, I hear a click. If I take a sharp sniff while they are tensed, my ears go into a state much like having my fingers in them (or being under water): My voice sounds as if it were inside my skull, and is much easier to check for intonation when singing in a group.

I have only met one or two other people who have this peculiar equipment, and its existence seems to be little known. One of them is an expert on the physics of hearing, and he told me that he had raised the question in an audiology class & been laughed at. Perhaps the ability is a genetic trait, like being able to wiggle one's ears (an independent one; for I cannot do that). But perhaps it can be learned, thru some sort of yogic discipline. Being invisible, it would also be untauntable.