Age differentially impacts monolingual and bilingual listeners' understanding of English speech in noise

Some bilinguals may perform worse understanding speech in noise (SIN) in their second language (L2) compared to monolinguals. Poorer performance has been found mostly for late bilinguals (L2 acquired after childhood) listening to sentences containing linguistic context, and less so for simultaneous/early bilinguals (L2 acquired during childhood) and when testing context-free stimuli. However, most studies tested younger participants–little is known about interactions with age. This study addresses this gap by measuring context-free SIN understanding via the Modified Rhyme Test in over 2,000 normal-hearing young and middle-aged bilingual and monolingual adults (ages 18–58; 23% bilinguals, all L2 English). Data collection is ongoing. Interim analyses reveal an interaction of age and group. Word recognition accuracy decreased as age increased for simultaneous and early bilinguals, but was stable for monolinguals and late bilinguals (though worse for bilinguals than monolinguals). Response time was faster for monolinguals but all groups slowed with increasing age at similar rates. These findings suggest an exaggerated age effect for bilingual SIN understanding across early and middle adulthood. [The views expressed in this abstract are those of the author(s) and do not necessarily reflect the official policy of the Department of Defense or the U.S. Government.]