Exploring dysarthric speech perception through listening effort

Listening effort is an emerging construct in dysarthric speech perception research and has the potential to complement intelligibility measures. The current study evaluated listening effort using pupillometry and perceived listening effort (PLE) ratings. Listeners completed a speech perception task in which they heard a speaker with dysarthria and a neurotypical speaker while an eye-tracking system measured their pupil dilation. Listeners also provided PLE ratings. Results showed that listeners had greater pupil dilation and rated PLE higher when listening to the speaker with dysarthria, even when the speech was accurately perceived. Additionally, incorrectly perceived trials were associated with higher pupil dilation and PLE ratings. Although the two measures of listening effort showed similar overall patterns, differences emerged, particularly in the interaction between dysarthria presence and perceptual accuracy. Finally, pupil dilation tended to decrease across trials while PLE ratings remained static. Overall, the findings suggest that listening effort is a valuable perceptual outcome to consider alongside speech intelligibility and may contribute to a more comprehensive understanding of the communication challenges associated with dysarthria. Further research is needed to better understand individual listener differences in listening effort and to establish the reliability and validity of the measures used to capture listening effort.