Rhythmic Abilities and Cognitive Load in Perception of Accented Second Language Speech

Languages differ in their rhythmic properties; for instance, English has higher temporal variability than Spanish. While listeners with stronger nonnative accents may better understand speech with corresponding accents, it remains unclear whether this general benefit relates to suprasegmental aspects and whether it extends to reduced cognitive load. As such, we examined how perceptual rhythmic ability, production rhythmic ability, and temporal variability in English speech production predict cognitive load during listening in L1 Spanish–L2 English bilinguals. Cognitive load was indexed via pupil size as participants listened to English sentences spoken with Spanish, American, and Mandarin accents. Overall, individuals with stronger rhythmic abilities exhibited greater cognitive load when processing L2 English, whose rhythm diverges from Spanish, compared to those with weaker rhythmic skills. Notably, for perceptual rhythmic ability, this difference was reduced in the American-accented English condition, suggesting that the rhythmic alignment between the accent and the target language facilitates processing.