Phonatory Deviation Diagram pre and post vocal rehabilitation

Area of Science:

• Speech-language pathology
• Acoustic analysis of voice
• Voice disorders

Background:

• Vocal rehabilitation aims to improve voice quality in individuals with dysphonia.
• Objective acoustic measures are needed to complement subjective perceptual evaluations of voice.
• The Pitch-Dispersion Diagram (PDD) is an acoustic analysis tool used to visualize voice characteristics.

Purpose of the Study:

• To determine if the Pitch-Dispersion Diagram (PDD) reflects vocal changes following voice therapy.
• To assess the correlation between PDD analysis and perceptual voice analysis outcomes.

Main Methods:

• Acoustic samples of the sustained vowel /ε/ were collected from 34 individuals with dysphonia before and after therapy.
• Voices were analyzed using PDD, classifying samples by density, shape, and quadrant location.
• Auditory perceptual analysis was conducted using a visual analog scale (VAS); statistical analyses were performed.

Main Results:

• Acoustic analysis revealed significant vocal improvements post-therapy, particularly in PDD shape (p = 0.031) and quadrant distribution (90% in quadrant 1).
• The vertical PDD shape pre-therapy shifted to a circular shape post-therapy.
• Perceptual deviation significantly reduced (p < 0.001), and PDD quadrant location strongly correlated with perceptual analysis (p < 0.001).

Conclusions:

• The Pitch-Dispersion Diagram (PDD) is a valuable tool for identifying vocal changes resulting from voice therapy.
• PDD analysis demonstrates a significant correlation with perceptual voice assessments, enhancing the evaluation of vocal rehabilitation.