A cross-dialect study of vowel production in Parkinson’s disease

The impact of dysarthria on vowel formant frequencies is well established. Additionally, it is understood that speaker dialects significantly influence formant frequencies. However, the specific interaction between dysarthria and speaker dialect remains a relatively unexplored area in research. This knowledge gap may hinder the generalizability of dysarthria findings from one regional dialect to speakers of other dialects. As an initial step in this research line, the current study investigates the interaction between regional dialects and dysarthria in Parkinson’s disease (PD) on vowel production. To do this, our study analyzes acoustic and kinematic data from speakers with and without dysarthria, representing Midwestern and Southern United States dialects. We examine both single-word repetitions and passage-reading contexts, recognizing that there may be a significant task effect. The study includes 50 speakers, with 24 speakers (10 PD, 14 control) from the Southern Dialect (collected in Louisiana and Florida) and 26 speakers (13 PD, 13 control) from the Upper Midwest dialect (collected in Wisconsin). The findings will shed light on the interaction between regional dialects and dysarthria, offering valuable insights for speech rehabilitation and understanding speech variations across different populations.