Comparison of Two Multiparameter Acoustic Voice Outcome Indices in the Treatment of Hyperfunctional Voice Disorders: Dysphonia Severity Index and Acoustic Voice Quality Index.

Introduction: The Dysphonia Severity Index (DSI) and Acoustic Voice Quality Index (AVQI) are the two widely used multiparameter acoustic instrumented indices that estimate dysphonia severity and track treatment outcomes. This study compared the performance of these two indices in identifying voice quality changes with eclectic voice therapy in individuals with hyperfunctional voice disorders (HFVD).

Method: Twenty individuals with HFVD including eight males and 13 females in the age range of 20-55 years received an eclectic voice therapy program named the Comprehensive Voice Habilitation Program. All the participants attended 15 sessions of voice therapy. DSI and AVQI measures were obtained at the baseline, immediate post therapy, 15 days post therapy (follow-up 1), and 60 days post therapy (follow-up 2). Repeated measures analysis of variance was performed to verify whether there were any differences between the time points for dependent variables DSI and AVQI. The effect sizes obtained for the DSI and AVQI measures were also noted.

Results: A significant difference was obtained between the baseline and post therapy, follow-up 1 and follow-up 2 for AVQI measure with a very large effect size, ηp2 = 0.451. In contrast, DSI showed a significant difference only between the baseline and follow-up 1 with effect size, ηp2 = 0.187.

Conclusions: The results of this study confirmed that both DSI and AVQI were effective in tracking the changes in the severity of dysphonia. However, when compared, AVQI appeared to be more sensitive than DSI in potentially reflecting the effect of eclectic voice therapy in HFVD.