Cognitive Predictors of Perception and Adaption to Dysarthric Speech in Older Adults.

Purpose: In effortful listening conditions, speech perception and adaptation abilities are constrained by aging and often linked to age-related hearing loss and cognitive decline. Given that older adults are frequent communication partners of individuals with dysarthria, the current study examines cognitive-linguistic and hearing predictors of dysarthric speech perception and adaptation in older listeners.

Method: Fifty-eight older adult listeners (aged 55-80 years) completed a battery of hearing and cognitive tasks administered via the National Institutes of Health Toolbox. Participants also completed a three-phase familiarization task (pretest, training, and posttest) with one of two speakers with dysarthria. Elastic net regression models of initial intelligibility (pretest) and intelligibility improvement (posttest) were constructed for each speaker with dysarthria to identify important cognitive and hearing predictors.

Results: Overall, the regression models indicated that intelligibility outcomes were optimized for older listeners with better words-in-noise thresholds, vocabulary knowledge, working memory capacity, and cognitive flexibility. Despite some convergence across models, unique constellations of cognitive-linguistic and hearing parameters and their two-way interactions predicted speech perception and adaptation outcomes for the two speakers with dysarthria, who varied in terms of their severity and perceptual characteristics.

Conclusion: Here, we add to an extensive body of work in related disciplines by demonstrating age-related declines in speech perception and adaptation to dysarthric speech can be traced back to specific hearing and cognitive-linguistic factors.