Exploring The Validity of Acoustic Measurements and Other Voice Assessments

There are different parts of a battery of voice assessments to assess voice functions and voice quality. The objective assessment of voice quality using acoustics is recommended and two measurements such as the Acoustic Voice Quality index, 03.01 (AVQI) and the Acoustic Breathiness Index (ABI) are leading in this domain. The purpose of this study was to verify the validity between these two acoustic measurements and other dimensions of the voice assessments (the Voice Handicap Index-10 (VHI-10) and the laryngeal imaging evaluation of the larynx and vocal folds).

We used a retrospective database of 150 participants (37 vocally healthy participants and 113 dysphonic patients). To test the validity between the acoustic measurements and the other voice assessments the concurrent validity and diagnostic precision were analyzed using Pearson correlation coefficient and the receiver operating characteristic (ROC) statistics with likelihood ratios.

The VHI-10 score presented moderate-significant correlations with the AVQI and the ABI, r= 0.477, P < 0.001 (r²= 0.228) and r= 0.426, P < 0.001 (r²=0.181), respectively. The larynx alteration presented low-significant correlations with the AVQI (r= 0.362, P < 0.001, r²= 0.131), and ABI (r= 0.371, P < 0.001, r²= 0.138), respectively. The area under the curve (AUC) of ROC was almost reasonable ranging from 0.701 to 0.737; except between ABI and VHI-10 (AUC= 0.689). The highest AUC was between the AVQI and VHI-10 at a threshold of 2.10; the highest specificity was between the ABI and VHI-10 at a threshold of 3.77. However, the lowest sensitivity was between ABI and VHI-10 while the lowest specificity was between the laryngeal diagnosis and the ABI.

AVQI and ABI presented significantly lower concurrent validity and diagnostic precision when the reference is not the auditory-perceptual judgment of voice quality. However, AVQI seems to be for some validity aspects a more reasonable classifier of vocal handicap and laryngeal alteration than ABI. Both AVQI and ABI values can broaden their range of assessment for the clinical user, thus showing more relationships between the individual voice examination methods.