The impact of prior topic awareness on listening effort during speech perception

Most standard speech perception tests use unrelated sentences where the topic changes for each stimulus. This unrealistic paradigm is expedient but might overlook an important aspect of speech processing and effort, which is how listeners use expectations and topic awareness to enable easier repair of misperceived words. We hypothesize that the effort of mentally repairing misperceived words will be reduced when individuals have advance topic awareness of upcoming sentences. In this study, individuals with normal hearing and hearing loss heard sentences with a masked target word that required retroactive mental repair using later context. Sentences were either preceded by the presence or absence of a related priming word presented visually to simulate advance topic knowledge. Listening effort for these sentences was measured by changes in pupil size that were linked with the exact timing of the word being repaired. When the target word is masked in a sentence, pupil dilation increases immediately after the missing word, and that dilation is modulated by the helpfulness of the prime before the sentence.