Italian Vowel and Consonant (co)articulation in Parkinson's Disease: extreme or reduced articulatory variability?

The present study investigates primarily on cross-speaker variability in the amplitude and duration of gestures, discussing the first data available on the articulation of consonants and vowels in Italian Parkinson's Disease (PD) dysarthric speech. Observations on PD speech gesture variability reported in the literature are not consistent, ranging from a decreased to an increased gestures' amplitude. In this study, we discuss acoustic and kinematic data (3D electromagnetic articulograph AG501) on Italian bilabial stops and two vowels ([i], [a]) produced by two mild-to-severe PD speakers and two peer healthy controls. Our results show that both increased and decreased amplitude and duration can be reported even in one subject's productions, if considering different gestures (opening vs. closing) or different planes (vertical vs. horizontal).