Add discussion of outer and middle ears

[pmcharrison]

Discuss the pinna, the comb filtering that tell you where the sound is coming from, etc.

The ossicles are located within the inner ear. They are a collection of small bones that transport sound vibrations from the eardrum to the oval window, the entrance to the inner ear. An important function of the ossicles is to ‘focus’ the incoming vibrational energy into a smaller area, so as to increase the force that it delivers. This is essential for communicating vibrations from the air to the fluid in the cochlea; otherwise much of the vibrational energy would simply be reflected backwards out of the ear.

[pmcharrison]

Unclear which chapter this would fit in, maybe it needs to be its own chapter.