Research on infant vocal development has provided notable insights into vocal interaction with caregivers, elucidating growth in foundations for language through parental elicitation and reaction to vocalizations. A role for infant vocalizations produced endogenously, potentially providing raw material for interaction and a basis for growth in the vocal capacity itself, has received less attention. We report that in laboratory recordings of infants and their parents, the bulk of infant speech-like vocalizations, or "protophones", were directed toward no one and instead appeared to be generated endogenously, mostly in exploration of vocal abilities. The tendency to predominantly produce protophones without directing them to others occurred both during periods when parents were instructed to interact with their infants and during periods when parents were occupied with an interviewer, with the infants in the room. The results emphasize the infant as an agent in vocal learning, even when not interacting socially and suggest an enhanced perspective on foundations for vocal language.

中文翻译：

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社会性和内生性婴儿发声

婴儿声带发展的研究为与护理人员的声带互动提供了重要的见识，阐明了通过父母的启发和对声带反应的语言基础的增长。内源性产生婴儿发声的作用，可能为互动提供原材料，并成为发声能力本身增长的基础，因此受到的关注较少。我们报告说，在婴儿及其父母的实验室录音中，大部分类似婴儿语音的发声或“ protophones”是针对任何人的，而似乎是内生的，主要是在发声能力的探索中。在指示父母与婴儿互动的过程中以及在父母被访调员所占据且婴儿在房间里的时期，都发生了主要生产原声电话而不将其定向给他人的趋势。研究结果强调了婴儿即使在没有社交互动的情况下也可以作为发声学习的媒介，并暗示了对发声语言基础的更高见解。