L2 cross-linguistic influence on L1 perception: Evidence from heritage speakers and long-term immigrants

This study investigates cross-linguistic influence of a second language (L2) on the first language (L1) perception in two distinct bilingual populations: Korean heritage speakers (n = 30) and long-term immigrants (n = 26) in the USA, compared to Korean-immersed speakers in South Korea (n = 30). By leveraging the differences in language-specific cue primacy in stop consonants between Korean and English, the present study examined L2 (English) influence in participants’ perceptual cue weighting and discrimination of Korean laryngeal categories through a three-alternative forced-choice identification task and a speeded AX discrimination paradigm. The results indicated divergent patterns of cross-linguistic influence for the two bilingual groups. While heritage speakers showed a decreased reliance on the onset f0 cue, suggesting an assimilatory effect of English, long-term immigrants relied more heavily on this cue than Korean-immersed speakers, suggesting dissimilation with English. Furthermore, in discriminating Korean stops based on f0 differences, heritage speakers demonstrated decreased accuracy while long-term immigrants outperformed Korean-immersed speakers. In addition, individual weighting of f0 in the identification task was found to be predictive of discriminatory performance. Overall, the findings underscore the importance of L1 input and experience in determining the nature of cross-linguistic influence in L1 speech perception.