Ohde R N
J Acoust Soc Am. 1985 Nov;78(5):1554-61. doi: 10.1121/1.392791.
Fundamental frequency (F0) and voice onset time (VOT) were measured in utterances containing voiceless aspirated [ph, th, kh], voiceless unaspirated [sp, st, sk], and voiced [b, d, g] stop consonants produced in the context of [i, e, u, o, a] by 8- to 9-year-old subjects. The results revealed that VOT reliably differentiated voiceless aspirated from voiceless unaspirated and voiced stops, whereas F0 significantly contrasted voiced with voiceless aspirated and unaspirated stops, except for the first glottal period, where voiceless unaspirated stops contrasted with the other two categories. Fundamental frequency consistently differentiated vowel height in alveolar and velar stop consonant environments only. In comparing the results of these children and of adults, it was observed that the acoustic correlates of stop consonant voicing and vowel quality were different not only in absolute values, but also in terms of variability. Further analyses suggested that children were more variable in production due to inconsistency in achieving specific targets. The findings also suggest that, of the acoustic correlates of the voicing feature, the primary distinction of VOT is strongly developed by 8-9 years of age, whereas the secondary distinction of F0 is still in an emerging state.
对8至9岁儿童在发包含清送气音[ph, th, kh]、清不送气音[sp, st, sk]和浊音[b, d, g]塞音的语音时的基频（F0）和声门起始时间（VOT）进行了测量，这些语音是在[i, e, u, o, a]语境中发出的。结果显示，VOT能够可靠地区分清送气音与清不送气音以及浊塞音，而F0除了在第一个声门周期（此时清不送气音与其他两类形成对比）外，能显著地区分浊音与清送气音和清不送气音。基频仅在齿龈和软腭塞音环境中能够持续区分元音高度。在比较这些儿童和成年人的结果时发现，塞音浊音化和元音质量的声学相关不仅在绝对值上不同，在变异性方面也存在差异。进一步分析表明，由于在实现特定目标时的不一致性，儿童在发音上的变异性更大。研究结果还表明，在浊音特征的声学相关中，VOT的主要区别在8至9岁时已强烈发展，而F0的次要区别仍处于形成状态。
