How to "Box an Ear"
Cup your hands and in a wide, fast, circular motion, slam them both against your opponent's ears as hard as you can.
Strike with the palms of your hands not your fingers.
Boxing the ears is an underused technique that can produce a violent sound wave that has the potential to blow out your attacker's eardrums.
It can also cause extreme vertigo for your attacker, giving you valuable time to get away.