Abstract:
PURPOSE:
to analyze the discriminating power of the phonatory deviation diagram (PDD) in assessing the predominant voice type and severity of voice deviance in children.
METHODS:
samples of the sustained vowel /ε/ were collected from 93 children. The severity of voice deviance and vocal quality were assessed with the aid of a visual analog scale. The PDD was used in the acoustic analysis, with an assessment of the distribution of the voice signals according to the area, quadrant, shape, and density in the diagram. The results were obtained from the statistical analysis of the variables using the test for equality of proportions, chi-squared test (Χ(2)), and Spearman's correlation. The level of statistical significance was set at ≤ 5% across analyses.
RESULTS:
a positive and statistically significant correlation was found between the classification based on the PDD quadrants and the severity of voice deviance for all the parameters analyzed except strain, which showed a negative correlation. Statistically significant differences were also noted in the proportion of children with voice roughness, breathiness, strain, and instability in relation to the area, quadrant, and shape in the PDD. There were no significant differences between the proportion of children with and without voice deviation for the evaluated parameters regarding the distribution of the voice samples in the quadrants.
CONCLUSION:
the PDD was capable of distinguishing the predominant vocal quality based on the distribution of the signals in the quadrants, although it could not discriminate between healthy and disordered children's voices.
Keywords:
Voice quality; Acoustics; Dysphonia; Voice disorders; Child