Bilingualism research demonstrates that the potential merger of vowel categories across a speaker’s two languages is affected by the age of acquisition of the second language. For heritage bilinguals, however, there is no clear L1 and L2, since they acquire their heritage language in early childhood, but become dominant in the mainstream language of society as adults. Heritage bilinguals may nevertheless will acquire distinct vowel systems in their two languages, rather than a merged system. In this study, the back vowels of California English and Seoul Korean, two varieties that are spoken by bilingual second-generation Korean Americans in California, were collected in natural speech. Formant measurements were analyzed using linear mixed effects regression modeling and generalized additive mixed modeling to see whether the vowels of each language were similar or different in their formant contours. As predicted, the bilinguals maintained distance between the vowels of both languages across their durations, and the phonological effects of coarticulation were found to be stronger in English than in Korean. The differences are attributed to “multicompetence” in heritage bilinguals’ phonology (Cook, 2020), or the interrelationship of multiple systems that exist and interact in the bilingual mind without merging completely, in opposition to models that frame heritage bilingualism as inherently imbalanced in favor of the dominant language.

双语研究表明，说话者两种语言中元音类别的潜在合并受第二语言习得年龄的影响。然而，对于传统双语者来说，没有明确的 L1 和 L2，因为他们在幼儿时期获得传统语言，但成年后成为社会主流语言的主导。然而，传统双语者可能会在他们的两种语言中获得不同的元音系统，而不是合并的系统。在这项研究中，加利福尼亚英语和首尔韩语的后元音是在自然语音中收集的，这两个变体是加利福尼亚州双语第二代韩裔美国人所说的两种变体。使用线性混合效应回归模型和广义加性混合模型分析共振峰测量，以查看每种语言的元音在共振峰轮廓上是相似还是不同。正如预测的那样，双语者在其持续时间内保持两种语言元音之间的距离，并且发现协同发音的语音效应在英语中比在韩语中更强。这些差异归因于传统双语者语音学中的“多重能力”（Cook，2020），或者是双语思维中存在和相互作用的多个系统之间的相互关系，而不是完全融合，这与将传统双语者视为天生不平衡的模式相反。占主导地位的语言。双语者在其持续时间内保持两种语言元音之间的距离，并且发现协同发音的语音效应在英语中比在韩语中更强。这些差异归因于传统双语者语音学中的“多重能力”（Cook，2020），或者是双语思维中存在和相互作用的多个系统之间的相互关系，而不是完全融合，这与将传统双语者视为天生不平衡的模式相反。占主导地位的语言。双语者在其持续时间内保持两种语言元音之间的距离，并且发现协同发音的语音效应在英语中比在韩语中更强。这些差异归因于传统双语者语音学中的“多重能力”（Cook，2020），或者是双语思维中存在和相互作用的多个系统之间的相互关系，而不是完全融合，这与将传统双语者视为天生不平衡的模式相反。占主导地位的语言。