Examining how bilingual infants experience their dual language input is important for understanding bilingual language acquisition. To assess these language experiences, researchers typically conduct language interviews with caregivers. However, little is known about the reliability of these parent reports in describing how bilingual children actually experience dual language input. Here, we explored the quantitative nature of dual language input to bilingual infants. Furthermore, we described some of the heterogeneity of bilingual exposure in a sample of French–English bilingual families. Participants were 21 families with a 10‐month‐old infant residing in Montréal, Canada. First, we conducted language interviews with the caregivers. Then, each family completed three full‐day recordings at home using the Language Environment Analysis recording system. Results showed that children’s proportion exposure to each language was consistent across the two measurement approaches, indicating that parent reports are reliable for assessing a bilingual child’s language experiences. Further exploratory analyses revealed three unique findings: (a) there can be considerable variability in the absolute amount of input among infants hearing the same proportion of input, (b) infants can hear different proportions of language input when considering infant‐directed versus overheard speech, (c) proportion of language input can vary by day, depending on who is caring for the infant. We conclude that collecting naturalistic recordings is complementary to parent‐report measures for assessing infant’s language experiences and for establishing bilingual profiles.

中文翻译：

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双语婴儿实际上会听到什么？评估对双语学习的10个月大的孩子的语言输入量度。

检查双语婴儿如何体验双语输入对于理解双语语言习得很重要。为了评估这些语言体验，研究人员通常会与护理人员进行语言访谈。但是，关于这些父母报告在描述双语儿童实际上如何体验双语输入方面的可靠性知之甚少。在这里，我们探讨了双语婴儿输入双语的定量性质。此外，我们在法语-英语双语家庭样本中描述了双语接触的某些异质性。参加者为21个家庭，其10个月大的婴儿居住在加拿大蒙特利尔。首先，我们与照顾者进行了语言访谈。然后，每个家庭都使用Language Environment Analysis录制系统在家里完成了三天的全天录制。结果表明，在两种测量方法中，儿童接触每种语言的比例是一致的，这表明父母的报告对于评估双语儿童的语言体验是可靠的。进一步的探索性分析揭示了三个独特的发现：（a）听到相同比例的输入的婴儿中，绝对输入量可能存在很大差异；（b）考虑以婴儿为主的语音与听到的语音时，婴儿可以听到不同比例的语言输入，（c）语言输入的比例每天可能有所不同，具体取决于谁照顾婴儿。