Analysis of Voice in Parkinson's Disease Utilizing the Acoustic Voice Quality Index.

Objectives: The purpose of this study was to analyze the acoustic voice quality index (AVQI) in relation to perceptual analysis and disease stage in speakers with Parkinson's disease (PD).

Study Design: Cross-sectional study.

Methods: The following data were gathered from the Parkinson's Disease Speech corpus of Tampere University (PDSTU): prolonged vowels and reading samples from native Finnish speakers with PD (n = 34), speaker demographic information, and Hoehn and Yahr scale scores. AVQIv03.01 analysis was completed with Praat. Expert raters utilized the GRBASI scale (GRBASI: grade, roughness, breathiness, asthenia, strain, instability) to assess voice quality. AVQI scores were analyzed in relation to GRBASI ratings and disease stage, as measured by the Hoehn and Yahr scale, utilizing correlation analysis.

Results: AVQI scores ranged from -0.11 to 4.46 (mean = 1.64, SD = 1.39), GRBASI average total scores ranged from 0-1.83 (mean = 0.66, SD = 0.50), and Hoehn and Yahr scale scores ranged from 1- 4. A statistically significant correlation between AVQI scores and GRBASI ratings was found (r = 0.508, P = 0.01). Several significant correlations were also found between the parameters of AVQI and scores for G, R, B and A from GRBASI. Hoehn and Yahr scores correlated significantly with GRBASI total score (r =0.437, P = 0.01) but not with AVQI.

Conclusion: A significant correlation was found between GRBASI ratings and Hoehn and Yahr scores, but not between AVQI and Hoehn and Yahr scores.

Data Availability: Due to the nature of this research, participants of this study did not agree for their data to be shared publicly. Data may be made available on a case-by-case basis. Data will be available after the active phase of the study in 2028.