High-speed Laryngoscopic Analysis of Vocal Fold Vibration in Fatigued Voices

Abstract

Objectives To determine the physiological patterns in the vocal fold vibration between non-fatigued and fatigued voices using high-speed laryngscopic imaging and quantitative analysis. Methods Twenty amateur singers aged from 18 to 23 years (mean = 21.2 years, s.d. = 1.3 years) with normal voice participated in an extended singing task which induced vocal fatigue. Laryngscopic images of /i/ phonations using high-speed imaging system were recorded were taken before and after the singing task. The quantitative High-Speed Video Processing (HSVP) program was used to extract indices related to the antero-posterior dimension (length), transverse dimension (width), and the speed of opening and closing. Results A significant change (reduction) in the glottal length to width ratio index was found after the singing task, presumably due to vocal fatigue. This indicated either a significantly shorter (antero-posteriorly) or wider (transversely) glottis following vocal fatigue physiologically. Conclusion High-speed imaging technique can be used to identify vocal fatigue by examining the configuration of the glottis using quantitative analysis. This study was supported by a grant from the Hong Kong Research Grant Council General Research Fund (#HKU757811).