Acoustic Analysis of Mandarin Speech in Parkinson's Disease with the Effects of Levodopa

This study investigated prosodic and articulatory characteristics of parkinsonian speech by acoustic analysis of the read speech from 21 Mandarin-speaking Parkinson's Disease (PD) patients before and after administration of levodopa medication, and 21 age-and gender-matched healthy controls (HC). PD exhibited reduced F0 variability and increased minimum intensity during the closures of stops than HC. For females, PD also showed smaller vowel space area and vowel articulation index than HC. Administration of levodopa increased the mean, the max, and the range of F0, bringing them closer to those of HC, but little effect was found on other acoustic parameters. Correlation analysis between acoustic parameters and physiological/ pathological indices of PD showed that the only significant positive correlation was between pause ratio and UPDRS III score. The findings on acoustic differences between PD and HC can potentially be applied to diagnosis and speech therapy for PD.