Table 4.
Summary of t test comparing the two speaker groups, speakers with Parkinson's disease (PD) and healthy controls (HC), within each language.
| Variable | English native |
Korean native |
||||
|---|---|---|---|---|---|---|
| Comparison between PD and HC | Mean difference | p Value | Comparison between PD and HC | Mean difference | p Value | |
| AVS (in log) | PD < HC | 0.49 | <.01** | PD < HC | 0.25 | <.04* |
| VOT contrast scores | PD < HC | 0.33 | NS | PD < HC | 1.51 | .02* |
| nPVI-V | PD < HC | 2.34 | NS | PD < HC | 4.44 | <.01** |
| AR (syl/sec) | PD > HC | 0.21 | NS | PD > HC | 0.11 | NS |
Note. AVS = acoustic vowel space; VOT = voice onset time; nPVI-V = normalized pairwise variability index for vocalic intervals; AR = articulation rate; NS = not significant; syl/s = syllables per second.
*
= p < .05;
**
= p < .01.