Spatiotemporal analysis of vocal fold vibrations between children and adults

Abstract

Objectives/Hypothesis Aim of the study is to quantify differences in spatiotemporal features of vibratory motion in typically developing pre-pubertal 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 analysed. 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.

Measurement of Glottal Cycle Characteristics Between Children and Adults: Physiological Variations

“…The criterion of a minimum of 50 oscillation cycles of steady phonation was defined empirically and has been used successfully in previous studies. 31,33 The segmentation of the steady state phonation was guided by inspecting the pitch trace, Root Mean Square (RMS) contour, and wideband spectrogram on TF32 34 an acoustic software analysis program. The acoustic tracings were examined both visually and quantitatively for 20Hz shift in 20 millisecond window for steady state phonation.…”

“…Through qualitative analysis of glottal cycle montages, generated from high speed digital imaging Patel, Dixon, Richmond, Donohue (2012) 30 reported a higher incidence of posterior phonatory gap (girls = 85%, boys = 68%) and a predominantly open phase of the glottal cycle during modal phonation in typically developing 5–11 year old children. Quantitative assessment of vocal fold oscillations in typically developing prepubertal children (5–11 years) 31,32 revealed both temporal and spatial differences in vibratory motion compared to healthy adults. Children had greater cycle-to-cycle variability during normal phonation compared to adults, especially during the closing phase.…”

“…Children had greater cycle-to-cycle variability during normal phonation compared to adults, especially during the closing phase. 31 Spatially, the vocal fold oscillations in children were characterized by longer opening phase, increased longitudinal delay for the opening phase and decreased longitudinal delay between the anterior and medio-lateral parts for the closing phase. 31 However much remains to be investigated in terms of the pattern of change of the glottal area function in children.…”

Endoscopic Laser-Based 3D Imaging for Functional Voice Diagnostics

“…The in-house software "Glottis Analysis Tools" [26] enables the semi-automatic segmentation of the empty and typically darker glottis area in between the vocal folds. The additional information of the two-dimensional glottis contour is incorporated in the 3D model by a projection on the interpolated, closed 3D surface.…”

Accurate glottal model parametrization by integrating audio and high-speed endoscopic video data

“…Visual analysis techniques that are widely used, 59 especially for clinical investigation, include laryngeal (video) 60 fold vibrations in adults and in children [14,15]. …”