Phonatory Deviation Diagram pre and post vocal rehabilitation

Verify whether PDD reflects vocal changes obtained by vocal rehabilitation and whether it reflects the changes in perceptual analysis.

Samples of the sustained vowel / ε /, pre and post-therapy, from 34 individuals with different dysphonia diagnosis were collected. The voices were acoustically analyzed by the PDD and an auditory perceptual analysis was performed using a visual analog scale (VAS) of 100 points. The acoustic samples were classified according to PDD density (concentrate or spread), shape (horizontal, vertical or circular) and position within the quadrants of the graph (lower left = 1, = lower right = 2, upper right = 3 and upper left = 4). Statistical analysis of acoustic parameters, distribution of samples and correlation between acoustic analysis and auditory perceptual analysis were performed.

Acoustic data showed improvement after therapy. Density did not differ in the two moments, while shape showed differences pre and post-therapy (p = 0.031). The vertical form characterized pre-therapy samples (12, 35.29%), and the circular form was associated to post-therapy samples (7, 20.59%). In pre-treatment condition, samples were distributed in three of the four quadrants, while in post-therapy, 90% were located in the first quadrant (normality area). The average perceptual deviation reduced from moderate to mild-moderate (p <0.001). There is a relationship between quadrant location and perceptual analysis (p <0.001).

PDD is useful to identify changes acquired with voice therapy and correlates with perceptual voice analysis.