BIG BANG THEORY To understand what is actually happening inside an ear, consider the cochlea, a fluid-filled, snail shell--shaped organ buried deep in the inner ear. Sound travels through the air as pressure waves that are funneled down the ear canal to the eardrum, which vibrates like...a tiny drum. Its slight movements are relayed via three miniature bones (the hammer, stirrup, and anvil) to another membrane that covers the opening of the cochlea. When this membrane begins to dance, the vibrations are transmitted inside the cochlea's fluid center, which is lined with minuscule hairlike projections called cilia. Cilia in one area, the so-called basal turn, are set to jiggling by high-frequency sounds. If the source is low-intensity sound--such as the ticking of a wristwatch--nerves attached to these cilia conduct the stimuli to the auditory lobes of the brain, where they're deciphered as a tick tick tick. But if the noise is more intense, such as a shotgun blast, researchers speculate that the vibrations are so violent that they can, in effect, fell the affected cilia like an earthquake does trees.