Basilar membrane registers frequency by place along its graded length.

Evidence

Small structures respond better to higher frequencies than do large struc­ tures (compare, for example, the sizes of a violin and a double bass or the strings at the treble and bass ends of a piano). The basilar membrane there­ fore responds best to high frequencies where it is narrow and thin (at the base) and to low frequencies where it is wide and thick (at the apex). Since its thickness and width change gradually along its length, input pure tones at different frequency will produce a maximum basilar membrane move­ ment at different positions or “places” along its length. — David Howard, Jamie Angus, coustics and Psychoacoustics, 550

Categorization

• XREF: The violin-vs-double-bass analogy maps onto place theory of pitch used later in the book. — connects to: Hearing two tones as separate requires separate basilar membrane peaks — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 577
• DEFINE: Sets up the foundational ‘place analysis’ mechanism of cochlear frequency encoding.