Longer Vocal Tracts Lower and Crowd the Formants
The inverse relationship between tract length and every resonance: a longer tube puts all its formants lower and closer together. This is the size cue in voices, it is independent of pitch, and it is the mechanism behind the sex difference in formants taught further along. It also explains why formant measures and pitch measures in the seed paper behave as different traits rather than as one trait measured twice.
Questions this Concept answers
- Why can a person's formant spacing indicate body size independently of how low their voice sounds?
Learnt formant modulation via upper vocal tract movements in a marine mammal
The article opens by teaching the source-filter theory of vocal production: the vocal folds supply a fundamental frequency and its harmonics, while the upper vocal tract acts as a filter whose resona…