The purpose of this study was to evaluate quantitatively the parameters of the video laryngostroboscopy (VLS) and determine correlations between the VLS parameters and acoustic vocal function parameters. Digital VLS recordings, acoustic voice assessment, calculation of dysphonia severity index (DSI) and registration of voice range profile (VRP) were performed for 206 individuals: 50 healthy and 156 patients with mass lesions of vocal folds and paralysis. 90 of lesions were unilateral, 66 – bilateral. VLS parameters were derived using objective measures made from a single image taken from the VLS recording of a sustained vowel: glottal areas, glottal widths and distances, vocal fold angles. As the result of Fisher's linear discriminant analysis, 11 VLS measurements were identified to be relevant distinguishing between normal and pathological voice groups. Correlations between the VLS parameters and results of acoustic voice analysis parameters, DSI and VRP measurements were tested using Pearson's correlation coefficient. The correlations of VLS variables and acoustic voice measurements were moderate and statistically significant. In pathological voices numerical values of VLS parameters measured reveal significant deviances from these in normal voice; therefore quantification of VLS parameters appears to be sensitive and specific distinguishing normal and pathological voices patients groups. Analysis of correlations between the quantitative measurements obtained via VLS and acoustic voice parameters provides more versatile approach into the pathophysiology of phonation and suggests the documented and measurable evidence of complex mechanisms of vocal function. 
Correlation between the quantitative video laryngostroboscopic measurements and parameters of multidimensional voice assessment