van der Merwe A, Uys I C, Loots J M, Grimbeek R J, Jansen L P
S Afr J Commun Disord. 1989;36:29-41.
The concept of context sensitivity as borrowed from the coalition model has important implications for the interpretation of the symptoms of apraxia of speech and for a better understanding of the nature of the disorder. In this study which was part of the wider investigation into the effect of variation in contextual factors on apraxia of speech (van der Merwe, Uys, Loots and Grimbeek, 1987; 1988), the effect of two contextual factors namely sound structure and articulatory features on voice onset time, vowel duration and utterance duration was acoustically analysed. Four subjects with acquired apraxia of speech and one with developmental apraxia of speech were tested. Findings indicated that voice onset time is not context sensitive. Errors in voice onset time were not true substitutions with voiceless sounds but were inconsistent distortions due to an inability to keep interarticulator synchronization within the critical temporal boundaries of motor equivalence. Vowel and utterance duration were found to be context sensitive. The deviation in duration increased with increased complexity of the utterance. As was the case with the auditorily perceived symptoms, the temporal characteristics of apraxia of speech can also be classified into core symptoms and associated symptoms based on their context sensitivity.
从联合模型中借鉴的语境敏感性概念，对言语失用症症状的解释以及更好地理解该障碍的本质具有重要意义。在这项作为更广泛研究一部分的研究中，该更广泛研究旨在探讨语境因素变化对言语失用症的影响（范德默韦、乌伊斯、卢茨和格林贝克，1987年；1988年），对两个语境因素，即语音结构和发音特征对嗓音起始时间、元音时长和话语时长的影响进行了声学分析。对四名获得性言语失用症患者和一名发育性言语失用症患者进行了测试。研究结果表明，嗓音起始时间不具有语境敏感性。嗓音起始时间的错误并非是与清音的真正替换，而是由于无法在运动等效性的关键时间界限内保持关节间同步而导致的不一致扭曲。元音和话语时长被发现具有语境敏感性。时长偏差随着话语复杂度的增加而增大。与听觉感知症状的情况一样，言语失用症的时间特征也可根据其语境敏感性分为核心症状和相关症状。
