A Comparison of Vocal Function between Females with Benign Vocal Fold Lesions and Females with Normal Voices by Use of Electroglottograph

Abstract

Objective: To compare vocal function between females with benign vocal fold lesions, and females with normal voices by use of electroglottograph (EGG), also in addition to determining which EGG parameters were significantly correlated with the perceptual degree of dysphonia. Material and Methods: EGG data were obtained from 32 females with benign vocal fold lesions and 32 females with normal voices. The EGG parameter values were analyzed from their productions of four sustained vowels (/a:/, /u:/, /i:/, and /æ:/). Results: The two perturbation measures of EGG signals, EGG-jitter and EGG-shimmer of females with benign vocal fold lesions were significantly higher than those of normal females at a p-value<0.01 for all four vowels. EGG-SDF0 of females with benign vocal fold lesions were significantly higher than those of normal females at a p-value<0.01 for /i:/, and /æ:/. EGG-F0 of females with benign vocal fold lesions were significantly lower than those of normal females at a p-value<0.01 for /u:/, /i:/, and /æ:/. The differences in contact quotient were non-significant on all four sustained vowels between the two groups. In addition, EGG-SDF0 was found to be significantly correlated with the perceptual degree of dysphonia for four sustained vowels. Conclusion: The results of this study showed the differences between vocal function of females with benign vocal lesions and females with normal voices, using EGG parameters. Furthermore, EGG-SDF0 could be used as an indicator for the degree of severity of dysphonia in females with benign vocal fold lesions.