University of Washington, Seattle, WA, USA.
J Speech Lang Hear Res. 2012 Apr;55(2):596-608. doi: 10.1044/1092-4388(2011/10-0113). Epub 2011 Dec 29.
This study examines the influence of word frequency, phonological neighborhood density (PND), age of acquisition (AoA), and phonotactic probability on production variability and accuracy of known words by toddlers with no history of speech, hearing, or language disorders.
Fifteen toddlers between 2;0 (years;months) and 2;5 produced monosyllabic target words varying in word frequency, PND, AoA, and phonotactic probability. Phonetic transcription was used to determine (a) whole-word variability and (b) proportion of whole-word proximity (PWP; Ingram, 2002) of each target word produced.
Results show a significant effect of PND on PWP and variability (words from dense neighborhoods had higher PWP and lower variability than those from sparse neighborhoods), a significant effect of word frequency on variability (high-frequency words were less variable) but not proximity, and a significant effect of AoA on proximity (earlier acquired words had lower PWP) but not variability.
Results provide new information regarding the role that lexical and phonological factors play in the speech of young children; specifically, several factors are identified that influence variability of production. Additionally, by examining lexical and phonological factors simultaneously, the current study isolates differential effects of the individual factors. Implications for our understanding of emerging phonological representations are discussed.
本研究考察了词频、音韵近邻密度（PND）、习得年龄（AoA）和音位规则性对无言语、听力或语言障碍史的幼儿已知词汇产出变异性和准确性的影响。
15 名 2 岁零 0 个月至 2 岁零 5 个月的幼儿说出单音节目标词，这些词在词频、PND、AoA 和音位规则性上存在差异。使用音标转写确定（a）每个目标词的整体词变异性和（b）整体词接近度（PWP；Ingram，2002）的比例。
结果显示，PND 对 PWP 和变异性有显著影响（来自密集邻域的词比来自稀疏邻域的词具有更高的 PWP 和更低的变异性），词频对变异性有显著影响（高频词的变异性较低）但对接近度没有影响，AoA 对接近度有显著影响（较早习得的词具有较低的 PWP）但对变异性没有影响。
结果提供了关于词汇和语音因素在幼儿言语中的作用的新信息；具体来说，确定了几个影响产生变异性的因素。此外，通过同时检查词汇和语音因素，本研究分离了各个因素的差异影响。讨论了对新兴语音表征的理解的影响。
