Purpose: The impact of clear speech, increased vocal intensity, and rate reduction on acoustic characteristics of vowels was compared in speakers with Parkinson's disease (PD), speakers with multiple sclerosis (MS), and healthy controls. Method: Speakers read sentences in habitual, clear, loud, and slow conditions. Variations in clarity,…

Purpose: This study investigated how different instructions for eliciting clear speech affected selected acoustic measures of speech. Method: Twelve speakers were audio-recorded reading 18 different sentences from the Assessment of Intelligibility of Dysarthric Speech (Yorkston & Beukelman, 1984). Sentences were produced in habitual, clear,…

The primary purpose of this study was to investigate how speakers with Parkinson's disease (PD) and Multiple Sclerosis (MS) accomplish voluntary reductions in speech rate. A group of talkers with no history of neurological disease was included for comparison. This study was motivated by the idea that knowledge of how speakers with dysarthria…