One fish, uh, two fish: Effects of fluency and bilingualism on adults' novel word learning

Listeners utilize speech disfluencies to anticipate novelty in spoken language, but little is known about how speech disfluencies impact novel word learning. We investigated how monolingual and bilingual adults learn novel words under disfluent speech conditions, focusing on fillers such as uh and um. If fillers highlight novelty, they might be an especially potent cue during word learning; however, because fillers also signal uncertainty, listeners may be less willing to learn in a disfluent condition. We also tested whether an effect of fillers on word learning would be moderated by bilingual experience, expecting that bilinguals would be affected differently because their exposure to distributional information within each language is reduced relative to monolinguals. In Experiments 1 and 2, where participants were exposed only to novel words, we found that participants learned words equally well in fluent and disfluent conditions, and that this effect was not moderated by bilingual experience. In Experiment 3, when novel words were embedded within a larger set of known words, we observed a bilingualism by condition interaction, wherein bilinguals benefited from fluency, but monolinguals performed equally well across conditions. These findings suggest that monolinguals' word learning-unlike word processing-may be robust to variations in speaker fluency, but that language experience may moderate the effect of fluency on learning.