Auditory Scene Analysis
Suppose someone were standing on a lakeshore watching two handkerchiefs floating on the water surface in two trenches. Now suppose, simply by looking at the movement of the handkerchiefs, the person could tell you that the lake has some children splashing, someone casting a fishing rod, and a motor boat. Also suppose this person could tell the precise locations of these activities.
In effect, this is what human hearing is able to do. The trenches are analogous to the ear canals, and the handkerchiefs are the ear drums. Simply by attending to the vibrations of our ear drums, we have remarkable abilities for determining what is going on in the world (Bregman, 1990).
One purpose of the auditory system is to parse scenes into component sound sources.
Pitch is the principal way by which frequencies are reassembled into mental objects that typically correspond with real-world sources. Pitch is the mental label listeners attach to a set of spectral components.