Age effects in first language attrition: Speech perception by Korean-English bilinguals

This study investigated how bilinguals’ perception of their first language (L1) differs according to age of reduced contact with L1 (ARC) after immersion in a second language (L2). Twenty-one L1 Korean-L2 English bilinguals in the US ranging in ARC from 3 to 15, as well as 17 native Korean controls in Korea, were tested on perception of three L1 sound contrasts differing in similarity to L2 contrasts. Results showed that, in comparison to controls, bilinguals were less accurate on L1-specific contrasts; their accuracy, moreover, was significantly correlated with ARC, an effect most pronounced for the contrast most dissimilar from L2. These findings suggest that the earlier bilinguals are extensively exposed to L2, the less likely they are to perceive L1 sounds accurately; however, this relationship is modulated by cross-linguistic similarity. Additionally, a turning point in both L2 acquisition and L1 attrition of phonology appears to occur at around age 12.

本研究探讨了双语者在沉浸于第二语言（L2）之后，根据与第一语言（L1）接触减少的年龄（ARC）差异，其L1感知如何发生变化。在美国，21名ARC范围在3至15岁之间的L1韩语-L2英语双语者接受了测试，以及17名韩国本土韩语母语者作为对照组。测试内容为三个与L2对比相似度不同的L1音素对比感知。结果显示，与对照组相比，双语者在L1特定对比感知上准确性较低；此外，他们的准确性与ARC显著相关，这一效应在L2对比最不相似的情况下最为明显。这些发现表明，双语者越早广泛接触L2，他们感知L1音素的准确性就越低；然而，这种关系受到跨语言相似性的调节。此外，L2习得和L1语音学衰减的转折点似乎出现在大约12岁左右。