Statistical Analysis of the Reliability of Acoustic and Electroglottographic Perturbation Parameters for the Detection of Vocal Roughness

Abstract

The aim of this study was to verify whether the electroglottography (EGG) perturbation parameters could be superior indicators to traditional acoustic (Ac) measures, particularly for the detection of mild vocal roughness. Thirty-nine participants with muscle tension dysphonia (the MTD group), 48 dysphonic participants with vocal fold lesions (the organic group), and 40 nondysphonic participants (the control group) were enrolled in the study. Based on the severity of vocal roughness, each of the two dysphonic groups was divided into mildly and severely dysphonic subgroups. The Ac and EGG signals during sustained /e:/ phonation were recorded simultaneously. The period and amplitude perturbation quotients of both signals (Ac-PPQ/-APQ and EGG-PPQ/-APQ) were calculated. The receiver operating characteristic (ROC) analyses were applied to evaluate the discriminative capabilities. In the analyses between the control and each of the two dysphonic groups, the values of the areas under the curve (AUC) for EGG-PPQ were significantly higher than those for Ac-PPQ. Next, the ROC analyses between the control and mildly dysphonic MTD subgroup demonstrated that the AUC values for EGG-PPQ/EGG-APQ were significantly higher than those for Ac-PPQ/Ac-APQ. In the analyses of the mildly dysphonic organic group, the AUC value for EGG-PPQ was significantly higher than that for Ac-PPQ. The present study demonstrated that both the period and the amplitude perturbation parameters of the EGG signals showed higher diagnostic accuracies than those of Ac signals, especially for the detection of mild vocal roughness. These results suggest that the EGG perturbation parameters could provide better information than the traditional Ac perturbations.