Objective Quantitative Analysis of Laryngeal Glottal Gaps using High-Speed Video in Glottal Analysis Tools, a Case-Control Study

Quantitative voice analysis for clinical use has been focused upon for many years. The aim was to test if Glottal Analysis Tools (GAT) could be used, based on High-Speed Video (HSV) to quantify distances between the vocal folds at any place on the vocal folds. The software includes a reproduced computed film of the vocal fold movements online. 20 normal HSV and 30 with insufficient closure in the rear part of the vocal folds (rear glottal gap) were compared in a case-control study. The distance of trajectories was chosen at 50% and 10% from the rear part of the glottis and maximum and minimum distances between the vocal folds were defined during phonation in the 2 groups. It was possible to calculate the absolute data of insufficiency of closure of the vocal folds compared to normal HSV with a statistical difference of p<0,0001. An interesting result was in this material also that functional closure was found in all images in the middle of the vocal folds. In the future quantification of voice disorders should include specific parts of the Glottal Area Waveform (GAW) analyses based on HSV for better differentiation of function and pathology of the vocal folds.