Adult Aging, Hearing Acuity, and the Use of Prosody in Sentence Comprehension

In the present study, young adults, older adults with good hearing acuity, and older adults with mild-to-moderate hearing loss listened to and recalled sentences, a third of which had a prosodic marking in agreement with the syntactic structure, a third with a prosodic marking in conflict with the syntactic boundary, and a third with no pronounced prosodic marking. Participants’ pupil sizes were measured while listening to and preparing to recall the sentences as a measure of the amount of effort necessary for successful recall. All three participant groups had more accurate recall and reduced effort when prosody coincided rather than conflicted with the major syntactic boundary of the sentence, with the facilitation of congruent prosody being larger for the older adults than the younger adults. When participants made errors in their recall, responses tended to maintain a reasonable grammatical structure. Hearing-impaired older adults showed a non-significant trend toward resolving sentences with conflicting prosody by following the prosodic marking rather than the lexically determined syntactic boundary. Overall, the findings of the present study support the importance of prosody as a preserved and adaptive cue that can be utilized by older adults, even those with mild-to-moderate hearing loss, to maintain high levels of speech comprehension.