Alignment of prosodic focus affects listening effort

One of the most persistent problems in studying listening effort is distinguishing differences in effort without the confound of differences in speech intelligibility. We address this issue using a design where listening conditions contain similar acoustic content, but where comprehension effort is mediated by prosody. Stimuli were question-and-answer pairs where the answer corrects or affirms information from the question. In most trials, the answer had prosodic focus on the novel information. However, in select trials, the prosodic focus was incorrectly placed on already-known information. We hypothesized that inappropriate prosody would not affect intelligibility, but would elicit lingering listening effort, marked by elevated pupil dilation in the moments after stimulus presentation. We present results from 18 listeners with typical hearing, and discuss potential implications for listeners with cochlear implants who struggle to hear prosodic contours. This experimental design with novel discourse-level stimuli holds promise for distinguishing effortful auditory encoding from effortful comprehension as well as for exploring how the benefits of prosody in speech perception extend beyond improving accuracy, processing speed, and recall, to make listening easier.