Rapid airflow cutoffs generate harmonic-rich tones in reed instruments

Evidence

A reed vibrating against a shallot shuts off the flow of air rapidly and totally, and the consequent acoustic pressure variations are the sound source provided to the resonator. The rapid shutting off of the airflow produces a rapid, instantaneous drop in acoustic pressure within the shallot (as air flowing fast into the shallot is suddenly cut off). A rapid amplitude change in a waveform indicates a relatively high proportion of high harmonics are present. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1201

Categorization

• XREF: Connects to the chapter’s broader psychoacoustic theme of harmonics shaping timbre perception discussed elsewhere in the book. — connects to: Brass instruments operate acoustically as stopped-end tubes driven by lip reeds — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1234