Impact of Onset Age and Native-Speaker Input on L2 Phonological Acquisition in Korean EFL Learners

This study explores the influence of native-speaker input on second language (L2) pronunciation in a foreign language learning context. While age is often considered a critical factor in naturalistic settings, its impact may be less pronounced in formal learning environments, where the quality and consistency of input are more crucial. This research focuses on 92 Korean high school students, including 13 with study-abroad experience, who were divided into four groups based on input exposure: intensive, extracurricular, school classes, and a combination. Speech samples were assessed for comprehensibility and accentedness, and multiple regression analyses were conducted to evaluate the effects of onset age, input type, and input amount on oral proficiency. The findings show that neither onset age nor input quantity significantly influenced pronunciation, even when students were exposed to native-speaker teachers. However, students who received a combination of intensive input and extracurricular classes demonstrated marked improvement in their oral skills. This suggests that early exposure to native-speaker input alone may not guarantee success in mastering L2 pronunciation. Instead, consistent, varied, and immersive input, especially through study-abroad opportunities and extracurricular activities, plays a more significant role in developing oral proficiency and reducing foreign accents.