Acoustic, Phonetic and Prosodic Features of Parkinson's disease Speech

One of the frequent symptoms of Parkinson’s disease (PD) is a progressive dysarthria, the difficulty with articulation. Characterization of dysarthric speech is important, for instance, for the adaptation of speech recognition systems to PD patients. In this work, we investigate acoustic and phonetic-prosodic characteristics of speech produced by PD patients in the European Portuguese. For this purpose, a speech database, consisting mainly on phonetically rich sentences, has been collected from a group of patients with different degrees of PD severity and a healthy control group. Only vowels in a stressed position in continuous speech context (i.e. no sustained vowels) were analyzed. Results show a centralization of vowel formant frequencies for PD speech, as expected. However, some of the usual features for discriminating PD speech were not always found to be statistically significant. Furthermore, an analysis of acoustic, spectral and prosodic features towards classifying PD speech shows that dynamic features are of highest importance in this task.