Índice do grau geral do desvio vocal : desenvolvimento, avaliação e validação de um modelo de suporte à decisão para os falantes do português brasileiro

Abstract

Objective: To develop, evaluate, and validate an index of overall vocal deviation degree with a decision support model for Brazilian Portuguese speakers. Methods: This is a methodological study to validate an instrument The study followed these steps: preparing the database samples, extracting acoustic measures; developing a computer program for perceptual-auditory judgment; assessing agreement among judges; implementing a fuzzy analog-visual scale based on judges' judgments; developing the acoustic index; evaluating and validating the acoustic index. Two hundred and ninety-five voice samples from individuals with and without dysphonia were analyzed. A speech task composed of sustained vowel and connected speech was used, and perceptual-auditory judgment was performed by five experienced judges. Fifty acoustic measurements were extracted from the speech task. To enable the judges' auditory-perceptual judgment, a computer program called VoxMore: Auditory-Perceptual Judgment was created. In the stage of assessing agreement among judges, the intraclass correlation coefficient was used. Subsequently, a fuzzy analog-visual scale was developed, followed by the application of a multiple linear regression model to obtain the index of overall vocal deviation degree. Results: Predictor measures for the acoustic index were glottal noise excitation at 1,000 Hz, absolute deviation of the smoothed prominent cepstral peak median, harmonic-tonoise ratio, amplitude difference between the first harmonic and the third formant, and the third quartile of oscillation frequency. The index had a coefficient of determination of 0.84, indicating that the index of overall vocal deviation degree was able to explain 84% of the variability. Conclusion: The index showed good adherence and can provide information about the overall vocal deviation degree, as well as contribute to inferring underlying physiology and monitoring patient progression. Through the use of the overall vocal deviation degree index, it is possible to facilitate the training of new clinicians for more appropriate decision-making.