From the UCI ML archive, the description is "The data used in this
study were gathered from 188 patients with PD (107 men and 81 women) with
ages ranging from 33 to 87 (65.1 p/m 10.9) at the Department of Neurology
in Cerrahpaşa Faculty of Medicine, Istanbul University. The control group
consists of 64 healthy individuals (23 men and 41 women) with ages varying
between 41 and 82 (61.1 p/m 8.9). During the data collection process,
the microphone is set to 44.1 KHz and following the physician's examination,
the sustained phonation of the vowel /a/ was collected from each subject
with three repetitions."
The data here are averaged over the replicates.