Examining Listener Reaction Time in the Perceptual Assessment of Dysarthria

In the perceptual assessment of dysarthria, various approaches are used to examine the accuracy of listeners' speech transcriptions and their subjective impressions of speech disorder. However, less attention has been given to the effort and cognitive resources required to process speech samples. This study explores the relationship between transcription accuracy, comprehensibility, subjective impressions of speech, and objective measures of reaction time (RT) to further examine the challenges involved in processing dysarthric speech.

Sixteen listeners completed 3 experimental listening tasks: a sentence transcription task, a rating scale task, and an RT task that required responses to veracity statements. In each task, the speech stimuli included speech from 8 individuals with dysarthria.

Measurements from the 3 tasks were significantly related, with a correlation coefficient of -0.94 between average RT and transcription-based intelligibility scores and -0.89 between RT and listener ratings of dysarthria. Interrater reliability of RT measurements was relatively low when considering a single person's response to stimuli. However, reliability reached an acceptable level when a mean was taken from 8 listeners.

RT tasks could be developed as a reliable adjunct in the assessment of listener effort and speech processing.