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.
Significance Statement Individuals who frequently experiencing listening challenges may disengage in social situations, which puts them at risk for social isolation and negative health outcomes. Measuring the extent to which listeners engage during listening when background sound is present may improve our ability to detect people who are at risk of social isolation before it manifests. We utilize ecologically valid spoken stories to investigate how acoustic masking reduces intelligibility and listening engagement, using inter-subject correlation as a neural signature of engagement. We found that healthy listeners continue to engage with listening material even under adverse listening conditions and reduced speech intelligibility, although engagement is less when the level of background sound is high.
Competing Interest Statement
The authors have declared no competing interest.