Vocal Fold Motion in Healthy Women and Men During Normal, High-Pitch, and Soft Voice

What is it about?

Understanding vocal fold vibration is important for appropriate assessment and treatment of voice disorders. This study examines how healthy vocal folds vibrate during three common voice tasks: typical speech, high-pitch phonation, and soft phonation. Using high-speed videoendoscopy, we captured detailed, cycle-by-cycle motion of the vocal folds in a relatively large group of healthy adults. Using the glottal area waveform, which reflects how the vocal folds open and close during voicing, we extracted multiple quantitative measures describing vibration amplitude, timing, symmetry, and closure patterns. By comparing these measures across tasks and between males and females, this study establishes normative reference data for vocal fold function under different pitch and loudness conditions.

Why is it important?

Accurate assessment of voice disorders (dysphonia) depends on understanding how normal vocal folds behave across a range of speaking conditions. Current clinical tools like stroboscopy cannot capture rapid, cycle-to-cycle variations, limiting their diagnostic precision. This study addresses that gap by providing objective, high-resolution benchmarks using high-speed imaging. The findings also identify the most sensitive measures—Speed Quotient (SQ), Rate Quotient (RQ), Normalized Maximum Area Declination Rate (MADRn), and Amplitude-to-Length Ratio (ALR)—for detecting changes related to pitch and loudness. Importantly, the results show that pitch increases are driven primarily by cricothyroid muscle activation with minimal changes in vocal fold adduction, whereas soft phonation involves coordinated adjustments in both adduction and cricothyroid activity, producing more incomplete closure patterns. These task-dependent strategies, along with observed sex differences, enhance our ability to interpret vocal function and distinguish normal variation from pathology, ultimately improving diagnosis, treatment planning, and the development of advanced assessment tools. Notably, this is the first study to demonstrate how these physiological strategies can be quantitatively measured in the glottal area waveform using high-speed imaging.