Woodwind perturbation theory predicts how articulator constrictions shift formant frequencies

Evidence

In order to produce different sounds, the shape of the vocal tract is altered by means of the articulators to change its acoustic properties. The perturbation theory principles explored in the context of woodwind reed instruments (see Figure 4.23) can be employed here also (Kent and Read, 1992). Figure 4.38 shows the velocity nodes and antinode positions for the first three formants of the vocal tract during a neutral nonnasalized vowel, which can be confirmed with reference to the upper-right-hand part of Figure 4.23. Following the same line of reasoning as that presented in the context of Figure 4.23, the effect of constrictions (and therefore enlargements) on the first three formants of the vocal tract can be predicted as shown in Figure 4.39. For example, all formants have a volume velocity antinode at the lips, and a lip constriction therefore lowers the frequencies of all formants. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1347

Categorization

• XREF: Neat cross-instrument application of the same perturbation logic from the woodwind section, showing how the vocal tract is modeled as a wind instrument. — connects to: Vowel production shifts formants by perturbing vocal tract geometry like a woodwind instrument — David Howard, Jamie Angus, coustics and Psychoacoustics, 1361; Vocal tract resonances measurably shape wind instrument timbre; Vowel formant frequencies are predictable from the location of vocal tract constrictions

Broader Connections

• Vowel formant frequencies are predictable from the location of vocal tract constrictions #expands (0.88)
• Vowel production shifts formants by perturbing vocal tract geometry like a woodwind instrument #corroborates (0.86) — David Howard, Jamie Angus, coustics and Psychoacoustics, 1361
• Vocal tract resonances measurably shape wind instrument timbre #expands (0.74)