Vocal quality assessment: methodological approach for a perceptive data analysis

ABSTRACT Purpose: to present a methodological approach for interpreting perceptual judgments of vocal quality by a group of evaluators using the script Vocal Profile Analysis Scheme. Methods: a cross-sectional study based on 90 speech samples from 25 female teachers with voice disorders and/or laryngeal changes. Prior to the perceptual judgment, three perceptual tasks were performed to select samples to be presented to five evaluators using the Experiment script MFC 3.2 (software PRAAT). Next, a sequence of tests was applied, based on successive approaches of inter- and intra-evaluators’ behavior. Data were treated by statistical analysis (Cochran and Selenor tests). Results: with respect to the analysis of the evaluators' performance, it was possible to define those that presented the best results, in terms of reliability and proximity of analyses, as compared to the most experienced evaluator, excluding one. The results of the cluster analysis also allowed designing a voice quality profile of the group of speakers studied. Conclusions: the proposal of a methodological approach allowed defining evaluators whose judgments were based on phonetic knowledge, and drawing a vocal quality profile of the group of samples analyzed.