A struck membrane’s perceived pitch depends on suppressing inharmonic modes

Evidence

We label the lowest modes and give their frequency ratios, using 2.00 for the (1,1) mode, in figure 15.12. The mode series (1,1), (2,1), (3,1), and (4,1) has frequency ratios 2:3:4:4.98. If somehow the (0,1), (0,2), (1,2), (2,2), and (3,2) modes with their inharmonic frequency ratios can be kept relatively silent, the nearly harmonic (1,1), (2,1), (3,1), and (4,1) series will give a very pleasing nearly periodic tone of definite pitch. The (0,2) and (1,2), (2,2), and (3,2) modes can be brought under control by striking at a compromise point near their nodes, leaving them relatively quiescent. (The power going into a mode is proportional to the amplitude squared of the mode at the striking point.) However, the out-of-tune (0,1) mode has no nodal lines and cannot be avoided when the membrane is struck. — Eric J. Heller, Why You Hear What You Hear- An…, 1411

Categorization

• XREF: Connects to the reader’s auditory-perception theme: how pitch perception emerges from harmonic vs. inharmonic partial ratios, related to chapter 4-6 material on periodic tones. — connects to: Changing membrane tension during ringing produces a controlled pitch glide — David Howard, Jamie Angus, coustics and Psychoacoustics, 1324