The Accent Atlas: Effects of long-term exposure to nonnative accents on adaptive speech perception

Abstract

As mobility increases and virtual interactions grow, quickly adapting to diverse accents is essential for effective communication. While lab-based accent training promotes rapid adaptation to unfamiliar accents, whether prolonged environmental exposure to linguistic diversity yields similar benefits is unknown. We conducted a large-scale perceptual experiment involving 600 + participants across 15 U.S. states, utilizing a cross-modal word matching task to measure speech recognition in both non-native accented English and native English with background noise. Participants were recruited from linguistically diverse (LD) or linguistically homogeneous (LH) states. Linguistic diversity was defined based on the prevalence of non-English speaking residents (U.S. census data). Our findings were twofold: firstly, consistent with prior studies, only exposure to non-native accented speech—but not exposure to speech in noise—improved recognition of novel talkers with the same accent; secondly, individuals from the LD states outperformed those from LH areas in initial accented speech perception. However, by the end of the experiment, benefits from in-lab accent exposure did not differ significantly between the two groups, suggesting that short-term training could mitigate long-term environmental influences. These results illuminate the interplay between daily linguistic environments and accent adaptation, enhancing our understanding of speech perception's adaptivity in a multilingual context.