Eilers R E, Bull D H, Oller D K, Lewis D C
J Acoust Soc Am. 1984 Apr;75(4):1213-8. doi: 10.1121/1.390773.
Three groups of nine 5-11-month-old infants provided evidence of discrimination of speechlike stimuli differing only in vowel duration. Ease of discrimination was directly related to the magnitude of the ratio of the longer to shorter vowel. Group one infants discriminated three vowel duration contrasts (with ratios of 0.33, 0.67, and 1.0) embedded in a synthetic [mad] syllable; group two discriminated these same duration contrasts within the bisyllable [ samad ], and group three in the trisyllable [ masamad ]. In all cases, the contrasting durations were carried by the last vowel of the synthetic word. These same three infant groups failed to provide evidence of discrimination of a final position released stop consonant contrast ([mat] versus [mad]) cued by voice excitation during closure of the [d] and not the [t]. These results suggest that vowel duration may be a primary cue for infants' perception of the voicing of final position stop consonants.
三组共27名5至11个月大的婴儿提供了证据，证明他们能够区分仅在元音时长上有所不同的类似语音的刺激。区分的难易程度与较长元音与较短元音的比例大小直接相关。第一组婴儿能够区分嵌入在合成音节[mad]中的三种元音时长对比（比例分别为0.33、0.67和1.0）；第二组婴儿能够区分双音节[samad]中的相同时长对比；第三组婴儿能够区分三音节[masamad]中的相同时长对比。在所有情况下，对比时长都由合成词的最后一个元音承载。同样的这三组婴儿未能提供证据证明他们能够区分由[d]而非[t]的闭塞期间的语音激发所提示的词尾位置释放塞音对比（[mat]与[mad]）。这些结果表明，元音时长可能是婴儿感知词尾位置塞音浊音的主要线索。
