This investigation aimed at determining whether an acoustic quantification of the oral diadochokinetic (DDK)task may be used to predict the perceived level of speech impairment when speakers with Parkinson's disease(PD) are reading a standard passage. DDK sequences with repeated [pa], [ta], and [ka] syllables were collectedfrom 108 recordings (68 unique speakers with PD), along with recordings of the speakers reading a standardizedtext. The passage readings were assessed in five dimensions individually by four speech-language pathologists ina blinded and randomized procedure. The 46 acoustic DDK measures were merged with the perceptual ratings ofread speech in the same recording session. Ordinal regression models were trained repeatedly on 80% of ratingsand acoustic DDK predictors per dimension in 10-folds, and evaluated in testing data. The models developedfrom [ka] sequences achieved the best performance overall in predicting the clinicians' ratings of passage readings. The developed [pa] and [ta] models showed a much lower performance across all dimensions. The additionof samples with severe impairments and further automation of the procedure is required for the models to be usedfor screening purposes by non-expert clinical staff.