ABSTRACT
Many issues in human perception of sound are a direct result of the physical acoustics of the head, outer ears, ear canal, and so forth, interacting with sound fields. The interaction between the sound field and the object observing the sound field is fundamentally different from an interaction with, say, a tiny measurement microphone. This chapter aims to consider in talking about "the ear" is actually the human body, especially the head. As stated earlier, incoming sound waves interact with the head as a physical object, with sound waves "flowing" around the head via diffraction. Sound is airborne up until it strikes the eardrum; thenceforth sound is represented as vibration of the structures further inside the ear, although for convenience it is often called sound. Specific sounds are destined to stimulate specific nerves because the basilar membrane is stretched stiffly suspended at the entrance for sound and is stretched loosely at the far end.
