The Role of Perceptual Rhythmic Ability in the Perception of Accented Second Language Speech

Purpose: The present study examined the relationship between perceptual rhythmic ability and cognitive load during second language (L2) speech perception, and whether variation in cognitive load across accents differing in their rhythmic properties is more consistent with accounts emphasizing L1-based rhythmic interference or L2 target-language alignment. Method: Eighty-two L1 Spanish–L2 English bilinguals completed a pupillometry experiment in which they listened to English sentences spoken with accents differing in rhythmic properties (Spanish-accented English: lowest temporal variability; Mandarin-accented English: intermediate temporal variability; American-accented English: highest temporal variability). Cognitive load was indexed using pupil dilation. Participants also completed a perceptual rhythm discrimination task, along with additional tasks relevant to L2 speech processing. Results: Listeners with stronger perceptual rhythmic ability showed greater pupil dilation (indexing greater cognitive load) for Spanish-accented English, a reduced effect for Mandarin-accented English, and the weakest effect for American-accented English. This pattern suggests that alignment with listeners’ internalized expectations about the typical rhythmic properties of English is associated with more efficient processing of English sentences, and that listeners with better perceptual rhythmic ability are more sensitive to this alignment. Conclusions: The findings suggest that alignment between listeners’ rhythmic sensitivity and the rhythmic properties of the target language is correlated with cognitive load during L2 speech processing. Future research should examine how rhythmic sensitivity interacts with other factors across diverse L2 listening contexts and populations.