THE USE OF A DUAL-TASK PARADIGM FOR ASSESSING SPEECH INTELLIGIBILITY IN CLIENTS WITH PARKINSON DISEASE.

Differences in the clinical and ecological manifestations of reduced intelligibility for individuals with dysarthria related to Parkinson disease (PD) have been reported in the literature. The current study explored whether a dual-task paradigm could be used during intelligibility testing to collect speech samples that were representative of functional performance. Intelligibility was calculated for four speakers with PD and four age-matched controls (CG) based on single-word, sentences, and monologue tasks recorded in single-and dual-task conditions and a spontaneous speech sample. In the dual-task condition, speakers produced the target speech sample and performed a simultaneous motor task, turning a nut on a bolt. No significant differences in intelligibility were found for the CG. For speakers with PD, differences between conditions were statistically significant for all speech tasks. Intelligibility scores in the dual-task condition were lower, with variability between tasks and speakers noted. There was a significant difference between scores for the monologue in the single-task condition and the spontaneous sample; however, there was no significant difference between the monologue in the dual-task condition and the spontaneous sample. Findings suggest that including a simple motor task during a clinical assessment may help elicit speech samples that are representative of a speaker's typical speech production.

Influence of visual information on the intelligibility of dysarthric speech.

PURPOSE: To examine the influence of visual information on speech intelligibility for a group of speakers with dysarthria associated with Parkinson's disease. METHOD: Eight speakers with Parkinson's disease and dysarthria were recorded while they read sentences. Speakers performed a concurrent manual task to facilitate typical speech production. Twenty listeners (10 experienced and 10 inexperienced) transcribed sentences while watching and listening to videotapes of the speakers (auditory-visual mode) and while only listening to the speakers (auditory-only mode). RESULTS: Significant main effects were found for both presentation mode and speaker. Auditory-visual scores were significantly higher than auditory-only scores for the 3 speakers with the lowest intelligibility scores. No significant difference was found between the 2 listener groups. CONCLUSIONS: The findings suggest that clinicians should consider both auditory-visual and auditory-only intelligibility measures in speakers with Parkinson's disease to determine the most effective strategies aimed at evaluation and treatment of speech intelligibility decrements.