  Up to 90% of patients with Parkinson's disease (PD) suffer from hypokinetic
dysathria (HD) which is also manifested in the field of phonation. Clinical
signs of HD like monoloudness, monopitch or hoarse voice are usually quantified
by conventional clinical interpretable features (jitter, shimmer,
harmonic-to-noise ratio, etc.). This paper provides large and robust insight
into perceptual analysis of 5 Czech vowels of 84 PD patients and proves that
despite the clinical inexplicability the perceptual features outperform the
conventional ones, especially in terms of discrimination power (classification
accuracy ACC = 92 %, sensitivity SEN = 93 %, specificity SPE = 92 %) and
partial correlation with clinical scores like UPDRS (Unified Parkinson's
disease rating scale), MMSE (Mini-mental state examination) or FOG (Freezing of
gait questionnaire), where p < 0.0001.
