Comparison of Two Multiparameter Acoustic Indices of Dysphonia Severity: The Acoustic Voice Quality Index and Cepstral Spectral Index of Dysphonia

Abstract

The Acoustic Voice Quality Index (AVQI) and the Cepstral Spectral Index of Dysphonia (CSID) are two multiparameter acoustic indices designed to objectively estimate dysphonia severity and track treatment outcomes. This study compared the performance of these two indices using a common corpus of dysphonic speakers. Pre- and posttreatment samples of sustained vowel and connected speech were elicited from 112 patients across six diagnostic categories: unilateral vocal fold paralysis (n = 20), adductor spasmodic dysphonia (n = 20), primary muscle tension dysphonia (n = 20), benign vocal fold lesions (n = 20), presbylaryngis (n = 20), and mutational falsetto (n = 12). Listener ratings of dysphonia severity were compared to acoustic estimates of severity derived from two iterations of the AVQI (versions 2.02 and 3.01) as well as the CSID. The AVQI- and CSID-estimated severity for sustained vowels, connected speech, and a combined context were strongly correlated and significantly associated with listener ratings pretreatment, posttreatment, and change observed pre- to posttreatment. However, multiple regression analysis (adjusted for age, sex, and diagnostic category) revealed that the CSID generally accounted for more variance in listener-perceived severity ratings, and the contribution of the AVQI was small and statistically insignificant when the CSID was already in a combined model. The AVQI and the CSID were strongly correlated and both provided valid estimates of dysphonia severity. However, associations observed between the CSID- and listener-estimated dysphonia were almost uniformly stronger than either version of the AVQI, suggesting that the CSID outperformed the AVQI.