Changes in Vocal Fold Morphology During Singing Over Two Octaves.

The decreased caudomedial angle of the vocal fold from ƒ to 2ƒ (change in muscle belly from ";fat" to "thin") and increased angle from 2ƒ to 4ƒ (from "thin" to "fat") strongly supports the hypothesis that the vocal folds elongate and then tension when singing from ƒ to 4ƒ. This is the first study to show this relationship in vivo.