Accuracy Analysis of the Multiparametric Acoustic Indices AVQI, ABI, and DSI for Speech-Language Pathologist Decision-Making

Abstract

To investigate the accuracy of the Acoustic Voice Quality Index (AVQI), the Acoustic Breathiness Index (ABI), and the Dysphonia Severity Index (DSI) for speech-language pathologist (SLP) decision-making in the evaluation of teachers' voice conditions. Cross-sectional observational study with a convenience sample composed of 21 teachers "fit" in carrying out their work activities as a teacher, and 21 considered "unfit" for the same. All teachers underwent a voice evaluation, carried out by a voice-specialized speech-language pathologist. Voice evaluation included the SLP's opinion on whether the teachers presented "fit" or "unfit" for work. The voice and speech samples used for the AVQI and ABI scores were the mid-three seconds of a sustained vowel /a/, and a spontaneous count from 1 to 10. The following parameters were used to extract the DSI score: mid-three seconds of a sustained vowel /a/, maximum phonation time of a sustained vowel /a/, ascending vocal glide on the vowel /a/ until reaching the highest pitch, and sustained vowel /a/ at the softest possible vocal intensity. The t-test was used to compare the difference between the AVQI and ABI indices. The Mann-Whitney test was used for the DSI index, with a confidence level of 95%. The receiver operating characteristic curve (ROC) was used for accuracy analysis. There was a difference in AVQI values (P=0.008), ABI (P=0.014), and DSI (P=0.000) between groups. The cutoff points that revealed the highest specificity for the AVQI, ABI, and DSI respectively were 3.33 (sensitivity 57.1% and specificity 90.5%), 4 (sensitivity 57.1% and specificity 85.7%), and 1.62 (sensitivity 71.4% and specificity 90.5%). The AVQI, ABI, and DSI are instruments that provide robust voice information and can help speech-language pathologists in their decision-making about whether teachers must or must not be restricted in their vocal activities at work.