Imaging vocal fold medial surface vibration across chest, head, whistle, and creaky voice production using optical coherence tomography: A single subject study

This single-subject study used optical coherence tomography to image medial surface vibratory patterns during the production of chest, head, whistle, and creaky voice. Chest and head registers differed in medial surface thickness, with the chest voice produced with thicker vocal folds, greater vibratory amplitude, and a larger vertical phase difference than the head voice and the other voice qualities. The whistle voice was produced with tightly approximated vocal folds that were thicker than in the head voice and showed small but measurable vibrations. An alternating creaky and regular voice was produced without observable changes in vocal fold thickness.