Figure 3.

Speech and tremor data during the sustained vowel task. Closed circles, tremor severity; open circles, voice quality and control measures; in the left shaded area of each panel are the clinical baseline tremor ratings (up closed triangle), the best tremor rating obtained in the study (down closed triangle). Both baseline and best performance ratings were obtained with bilateral stimulation, along with the corresponding speech scores for the same conditions (up open triangle for clinical baseline and down closed triangle for best performance). Note that the HNR scale is reversed to show improvements in performance reflected in decreased values on the figure. r values reflect correlation between speech and tremor.