Kuo Christina, Weismer Gary
Department of Communication Sciences and Disorders, James Madison University, Harrisonburg, Virginia 22807, USA.
Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
J Acoust Soc Am. 2016 Jul;140(1):369. doi: 10.1121/1.4955310.
This study examined acoustic variation of vowels within speakers across speech tasks. The overarching goal of the study was to understand within-speaker variation as one index of the range of normal speech motor behavior for American English vowels. Ten male speakers of American English performed four speech tasks including citation form sentence reading with a clear-speech style (clear-speech), citation form sentence reading (citation), passage reading (reading), and conversational speech (conversation). Eight monophthong vowels in a variety of consonant contexts were studied. Clear-speech was operationally defined as the reference point for describing variation. Acoustic measures associated with the conventions of vowel targets were obtained and examined. These included temporal midpoint formant frequencies for the first three formants (F1, F2, and F3) and the derived Euclidean distances in the F1-F2 and F2-F3 planes. Results indicated that reduction toward the center of the F1-F2 and F2-F3 planes increased in magnitude across the tasks in the order of clear-speech, citation, reading, and conversation. The cross-task variation was comparable for all speakers despite fine-grained individual differences. The characteristics of systematic within-speaker acoustic variation across tasks have potential implications for the understanding of the mechanisms of speech motor control and motor speech disorders.
本研究考察了不同言语任务中说话者元音的声学变化。该研究的总体目标是将说话者内部的变化理解为美式英语元音正常言语运动行为范围的一个指标。十名美式英语男性说话者进行了四项言语任务，包括以清晰言语风格朗读例句（清晰言语）、朗读例句（例句朗读）、朗读段落（段落朗读）和对话言语（对话）。研究了处于各种辅音语境中的八个单元音。清晰言语在操作上被定义为描述变化的参考点。获取并检查了与元音目标惯例相关的声学测量数据。这些数据包括前三个共振峰（F1、F2和F3）的时间中点共振峰频率以及F1 - F2和F2 - F3平面上的派生欧几里得距离。结果表明，朝着F1 - F2和F2 - F3平面中心的收缩幅度在各项任务中按清晰言语、例句朗读、段落朗读和对话的顺序增加。尽管存在细微的个体差异，但所有说话者的跨任务变化都是可比的。跨任务的说话者内部系统声学变化特征对理解言语运动控制机制和运动性言语障碍具有潜在意义。
