Neural activity during story listening is synchronized across individuals despite acoustic masking

Abstract

Older people with hearing problems often experience difficulties understanding speech in the presence of background sound. As a result, they may disengage in social situations, which has been associated with negative psychosocial health outcomes. Measuring listening (dis-)engagement during challenging listening has received little attention thus far. We recruit normal-hearing human adults (both sexes) and investigate how speech intelligibility and engagement during naturalistic story listening is affected by the level of acoustic masking (12-talker babble). In Experiment 1, we observed that word-report scores were above 80% for all but the lowest SNR (-3 dB SNR) we tested, at which performance dropped to 54%. In Experiment 2, we calculated inter-subject correlation (ISC) in electroencephalography (EEG) data to identify dynamic spatial patterns of shared neural activity evoked by the stories. ISC followed a similar overall quadratic pattern as intelligibility data, however comparing ISC and intelligibility directly demonstrated that word-report performance declined more strongly with decreasing SNR compared to ISC. Observing significant ISC despite the presence of background noise suggests that participants were able to remain engaged despite missing segments of the story during especially difficult SNRs. Our work provides a novel approach to observe speech intelligibility and listener engagement using ecologically valid spoken materials which can be used to investigate (dis)engagement in older adults with hearing impairment.