the basic standard postulating that various frequencies arouse various places in mammalian auditory system structures. This ordering begins inside the cochlea, where various frequencies have a propensity to elicit maximal vibration at many differing locations along the basilar membrane and thus arouse many hair cells. The hair cells are discretely innervated, and thus various auditory nerve fibers react to a fairly restricted array of frequencies, with the maximal reaction at the best frequency of the fiber. This frequency-to-place mapping is kept in tact within the auditory cortex.