Articulatory Changes in Vowel Production following STN DBS and Levodopa Intake in Parkinson’s Disease

Table 2

Means (standard deviations) for vowel duration (msec.), acoustic vowel space (Hz²), and formant centralization ratio before and after STN DBS, off- and on-medication.

	Pre-op		Post-op
	Off-med	On-med	Off-med	On-med
Vowel duration (msec.)	105.0; (24.7)	103.2; (31.1)	102.6; (18.7)	102.8; (22.4)
Acoustic vowel space (Hz^2)	246006; (48045)	222166; (73934)	222430; (45823)	236810; (69166)
Formant centralization ratio	1.09; (0.06)	1.14; (0.09)	1.12; (0.06)	1.10; (0.07)