Bell partials are unequally spaced yet still produce a definite perceived pitch

Evidence

We return to the perceived pitch, or strike note, of bells and chimes, which vibrate at many frequencies, just as a plucked string does. The clapper of a bell excites many modes at once; a complex vibration of the bell ensues that is a linear superposition of all these modes, each of which corresponds to a pure sinusoidal partial. If a mode has an antinode where the clapper hits, it tends to be strongly excited, and if it has a node there, it will be silent. This is the same principle as a plucked string, the difference being that the partials of the bell are not evenly spaced. There is no definite period of the resulting tone, and no unambiguous frequency that is the inverse of this period, yet “true” bells have a definite pitch—after all, they have to be able to ring out a tune. — Eric J. Heller, Why You Hear What You Hear- An…, 2127

Categorization

• XREF: Connects to the plucked-string physics from earlier chapters in this book; the uneven spacing of partials is the core puzzle that pitch-perception theories must explain.