It is widely known that language influences the way speech sounds are categorized. However, categorization of speech sounds by bilinguals is not well understood. There is evidence that bilinguals have different category boundaries than monolinguals, and there is evidence suggesting that bilinguals’ phonemic boundaries can shift with language context. This phenomenon has been referred as the double phonemic boundary. In this investigation, the double phonemic boundary is tested in Spanish-English bilinguals (N = 18) and English monolinguals (N = 16). Participants were asked to categorize speech stimuli from a continuum ranging from /ga/ to /ka/ in two language contexts. The results showed phonemic boundary shifts in bilinguals and monolinguals which did not differ across language contexts. However, the magnitude of the phoneme boundary shift was significantly correlated with the level of confidence in using English and Spanish (reading, writing, speaking, and comprehension) for bilinguals, but not for monolinguals. The challenges of testing the double phonemic boundary are discussed, along with the limitations of the methodology used in this study.

众所周知，语言会影响语音分类的方式。然而，双语者对语音的分类还不是很清楚。有证据表明双语者与单语者具有不同的类别边界，并且有证据表明双语者的音位边界会随着语言上下文而变化。这种现象被称为双音位边界。在本次调查中，双音位边界在西英双语者（N  = 18）和英语单语者（N = 16）。参与者被要求在两种语言环境中对从 /ga/ 到 /ka/ 的连续体中的语音刺激进行分类。结果显示双语者和单语者的音位边界变化在不同语言环境中没有差异。然而，音素边界变化的幅度与双语者使用英语和西班牙语（阅读、写作、口语和理解）的信心水平显着相关，但与单语者无关。讨论了测试双音位边界的挑战，以及本研究中使用的方法的局限性。