External Validation of the Acoustic Voice Quality Index Version 03.01 With Extended Representativity

Abstract

Objectives: The Acoustic Voice Quality Index (AVQI) is an objective method to quantify the severity of overall voice quality in concatenated continuous speech and sustained phonation segments. Recently, AVQI was successfully modified to be more representative and ecologically valid because the internal consistency of AVQI was balanced out through equal proportion of the 2 speech types. The present investigation aims to explore its external validation in a large data set. Methods: An expert panel of 12 speech-language therapists rated the voice quality of 1058 concatenated voice samples varying from normophonia to severe dysphonia. The Spearman rank-order correlation coefficients ( r) were used to measure concurrent validity. The AVQI’s diagnostic accuracy was evaluated with several estimates of its receiver operating characteristics (ROC). Results: Finally, 8 of the 12 experts were chosen because of reliability criteria. A strong correlation was identified between AVQI and auditoryperceptual rating ( r = 0.815, P = .000). It indicated that 66.4% of the auditory-perceptual rating’s variation was explained by AVQI. Additionally, the ROC results showed again the best diagnostic outcome at a threshold of AVQI = 2.43. Conclusions: This study highlights external validation and diagnostic precision of the AVQI version 03.01 as a robust and ecologically valid measurement to objectify voice quality.