Phonovibrography: The Fingerprint of Vocal Fold Vibrations

A new approach for quantitative and objective analysis of vibration patterns of the vocal folds is presented. Vocal fold vibrations are recorded during sustained phonation in real time using a digital high-speed system coupled to a rigid endoscope. Within these high-speed movies, the edges of the oscillating vocal folds are detected by an adapted region-growing algorithm. The used segmentation algorithm is evaluated regarding its stability and correctness within 372 recordings proofing its clinical applicability. From the segmented vocal fold edges, a two-dimensional color encoded matrix is performed, visualizing the oscillations of the entire vocal fold edges over time. These created so called phonovibrograms allow a direct and objective view on the occurring laryngeal dynamics. The phonovibrograms can be used for assessing therapy progress and as a basis for further classification of different types of dysphonia. Phonovibrograms have the potential to serve as the first standard in endoscopic high-speed evaluation of vocal fold dynamics.