Breath-Group Intelligibility in Dysarthria

Purpose: This study was designed to determine whether within-speaker fluctuations in speech intelligibility occurred among speakers with dysarthria who produced a reading passage, and, if they did, whether selected linguistic and acoustic variables predicted the variations in speech intelligibility. Method: Participants with dysarthria included a total of 10 persons with Parkinson's disease and amyotrophic lateral sclerosis; a control group of 10 neurologically normal speakers was also studied. Each participant read a passage that was subsequently separated into consecutive breath groups for estimates of individual breath group intelligibility. Sixty listeners participated in 2 perceptual experiments, generating intelligibility scores across speakers and for each breath group produced by speakers with dysarthria. Results: Individual participants with dysarthria had fluctuations in intelligibility across breath groups. Breath groups of participants with dysarthria had fewer average words and reduced interq...