Munson Benjamin
Department of Communication Disorders, University of Minnesota, Minneapolis, MN 55455, USA.
J Speech Lang Hear Res. 2004 Feb;47(1):58-69. doi: 10.1044/1092-4388(2004/006).
Previous research has found developmental decreases in temporal variability in speech. Relatively less work has examined spectral variability, and, in particular, variability in consonant spectra. This article examined variability in productions of the consonant /s/ by adults and by 3 groups of children, with mean ages of 3;11 (years;months), 5;04, and 8;04. Specifically, it measured the influence of age, phonetic context, and syllabic context on variability. Spectral variability was estimated by measuring dynamic spectral characteristics of multiple productions of /s/ in sV, spV, and swV sequences, where the vowel was either /a/ or /u/. Mean duration, variability in duration, and coarticulation were also measured. Children were found to produce /s/ with greater temporal and spectral variability than adults. Duration and coarticulation were comparable across the 4 age groups. Spectral variability was greater in swV contexts than in sV or spV sequences. The lack of consistent effects of phonetic context on spectral variability suggests that the developmental differences were related to subtle variability in place of articulation for /s/ in the children's productions.
先前的研究发现，言语的时间变异性存在发育性降低。相对较少的研究考察了频谱变异性，尤其是辅音频谱的变异性。本文研究了成人以及三组平均年龄分别为3岁11个月、5岁4个月和8岁4个月的儿童在发辅音/s/时的变异性。具体而言，研究了年龄、语音语境和音节语境对变异性的影响。通过测量/s/在sV、spV和swV序列（其中元音为/a/或/u/）中的多次发音的动态频谱特征来估计频谱变异性。还测量了平均时长、时长变异性和协同发音。研究发现，儿童发/s/时的时间和频谱变异性比成人更大。四个年龄组在时长和协同发音方面相当。swV语境中的频谱变异性比sV或spV序列中的更大。语音语境对频谱变异性缺乏一致影响，这表明发育差异与儿童发音中/s/的发音部位的细微变异性有关。
