Voice onset time (VOT) of aspirated stop consonants is marked by variability and systematicity in adult speech production. The present study investigated variability and systematicity of voiceless aspirated stop VOT from 161 two- to five-year-old talkers of American English and Cantonese. Overall, many aspects of child VOT productions parallel adult patterns, the analysis of which can help inform our understanding of early speech production. For instance, VOT means were comparable between children and adults, despite greater variability. Further, across children in both languages, talker-specific VOT means were strongly correlated between [th] and [kh]. This correlation may reflect a constraint of “target uniformity” that minimizes variation in the phonetic realization of a shared distinctive feature. Therefore findings suggest that target uniformity is not merely a product of a mature grammar, but may instead shape speech production representations in children as young as two years of age.

送气塞辅音的发声时间（VOT）以成人语音产生的可变性和系统性为标志。本研究调查了 161 名 2 至 5 岁的说美式英语和粤语的人清送气停止 VOT 的变异性和系统性。总体而言，儿童 VOT 产生的许多方面与成人模式相似，对其进行分析可以帮助我们了解早期言语产生。例如，尽管变异性较大，但儿童和成人之间的 VOT 平均值具有可比性。此外，在使用两种语言的儿童中，特定于说话者的 VOT 均值在 [th ]和 [k h ] 之间密切相关。这种相关性可能反映了“目标一致性”的约束，该约束最大限度地减少了共享独特特征的语音实现的变化。因此，研究结果表明，目标一致性不仅仅是成熟语法的产物，而且可能塑造两岁儿童的言语表达表征。