A chair’s clang is the sum of many discrete harmonic oscillator modes.

Evidence

We compare the N-bead string and the membrane to hitting the seat of a metal folding chair with a knuckle. The waveform and the power spectrum of the sound are shown in figure 8.12. The spectrum crudely resembles that of a membrane. There are narrow peaks at many different frequencies—meaning that the clang of the chair (sound file chair.wav on whyyouhearwhatyouhear.com) is the sum of many pure sine tones. The chair, if sinusoidally driven at just one of these frequencies, would sound a pure sine tone even after the drive was turned off. — Eric J. Heller, Why You Hear What You Hear- An…, 867

Categorization

• CANDY: A metal chair clang explains that any noisy percussive sound decomposes into pure sine tones — great elevator-chapter opener.