Spatiotemporal analysis of vocal fold vibrations between children and adults.

OBJECTIVES/HYPOTHESIS: Aim of the study is to quantify differences in spatiotemporal features of vibratory motion in typically developing prepubertal children and adults with use of high speed digital imaging. STUDY
DESIGN: Prospective case-control study.
METHODS: Vocal fold oscillations of 31 children and 35 adults were analyzed. Endoscopic high-speed imaging was performed during sustained phonation at typical pitch and loudness. Quantitative technique of Phonovibrogram was used to compute spatiotemporal features. Spatial features are represented by opening and closing angles along the anterior and posterior parts of the vocal folds, as well as by left-right symmetry ratio. Temporal features are represented by the cycle-to-cycle variability of the spatial features. Group differences (adult females, adult males, and children) were statistically investigated.
RESULTS: Statistical differences were more pronounced in the temporal behavior compared to the spatial behavior. Children demonstrated greater cycle-to-cycle variability in oscillations compared to adults. Most differences between children and adults were found for temporal characteristics along the anterior parts during closing phase. The spatiotemporal features differed more between children and males than between children and females. Both adults and children showed equally high left-right symmetry.
CONCLUSIONS: Results suggest a more unstable phonation in children than in adults, yielding increased perturbation in periodicity. Children demonstrated longer phase delay in the anterior/posterior and medio-lateral parts during the opening phase compared to adults. The data presented may provide the bases for differentiating normal vibratory characteristics from the disordered in the pediatric population, and eventually assist in aiding the clinical utility of high speed imaging.