Vowel Production Associated with Cantonese Speakers of Parkinson’s Disease

The present findings suggest a reduced working vowel space with an apparent vowel centralization in PD speakers when compared with healthy controls. This was accompanied by restricted jaw and tongue movements. Such findings confirmed the articulatory undershooting in PD speakers, possibly due to hypokinetic dysarthria and other PD symptoms such as muscle rigidity and bradykinesia. It is also suggested that tVSA and F1RR are sensitive formant metrics for subtle changes in vowel articulation in PD.