You are right that the other poster's physics is way off, but I"m not sure what you mean by the energy of the bullet being irrelevant. Hold up a piece of paper and punch it. You won't punch through it -- the paper will just bend away. Shoot it. The bullet goes right through. When hitting a floppy target, the velocity does matter.
That said, I really don't know where the "ear would be deaf" idea is coming from. Hearing would be knocked out by a pressure wave. I'm no expert on high energy projectiles, but my intuition says that a bullet hitting an ear lobe would not cause a pressure wave. In addition, the pressure wave would move in the same direction as the bullet, meaning that it would not affect the ear at all. If there was an earring in the ear lobe, something that would cause a scattering, then maybe the effect claimed would materialize. A bullet merely hitting an ear lobe would not create a pressure wave to knock out hearing.