Clinical Neuropsychology Research Group, Institute of Phonetics and Speech Processing, Ludwig Maximilians University, Munich, Germany.
J Speech Lang Hear Res. 2021 Jun 18;64(6S):2196-2212. doi: 10.1044/2020_JSLHR-20-00267. Epub 2021 Mar 1.
Purpose The clinical assessment of intelligibility must be based on a large repository and extensive variation of test materials, to render test stimuli unpredictable and thereby avoid expectancies and familiarity effects in the listeners. At the same time, it is essential that test materials are systematically controlled for factors influencing intelligibility. This study investigated the impact of lexical and articulatory characteristics of quasirandomly selected target words on intelligibility in a large sample of dysarthric speakers under clinical examination conditions. Method Using the clinical assessment tool , a total of 2,700 sentence-embedded target words, quasirandomly drawn from a large corpus, were spoken by a group of 100 dysarthric patients and later transcribed by listeners recruited via online crowdsourcing. Transcription accuracy was analyzed for influences of lexical frequency, phonological neighborhood structure, articulatory complexity, lexical familiarity, word class, stimulus length, and embedding position. Classification and regression analyses were performed using random forests and generalized linear mixed models. Results Across all degrees of severity, target words with higher frequency, fewer and less frequent phonological neighbors, higher articulatory complexity, and higher lexical familiarity received significantly higher intelligibility scores. In addition, target words were more challenging sentence-initially than in medial or final position. Stimulus length had mixed effects; word length and word class had no effect. Conclusions In a large-scale clinical examination of intelligibility in speakers with dysarthria, several well-established influences of lexical and articulatory parameters could be replicated, and the roles of new factors were discussed. This study provides clues about how experimental rigor can be combined with clinical requirements in the diagnostics of communication impairment in patients with dysarthria.
目的 可理解度的临床评估必须基于大量的语料库和广泛的测试材料变化，以使测试刺激难以预测，从而避免听众的期望和熟悉度效应。同时，系统地控制测试材料对可理解度有影响的因素至关重要。本研究在临床检查条件下，调查了随机选择的目标词的词汇和发音特征对 100 名发音障碍患者大样本的可理解度的影响。
方法 使用临床评估工具，从一个大型语料库中随机抽取了总共 2700 个句子嵌入的目标词，由 100 名发音障碍患者朗读，然后由通过在线众包招募的听众转录。分析了词汇频率、音位邻域结构、发音复杂性、词汇熟悉度、词类、刺激长度和嵌入位置对转录准确性的影响。使用随机森林和广义线性混合模型进行分类和回归分析。
结果 在所有严重程度下，频率较高、音位邻域较少且较不频繁、发音复杂性较高、词汇熟悉度较高的目标词的可理解度得分显著较高。此外，目标词在句首比在句中或句尾更具挑战性。刺激长度有混合效应；词长和词类没有影响。
结论 在对发音障碍患者的可理解度进行的大规模临床检查中，可复制几个已确立的词汇和发音参数的影响，并讨论了新因素的作用。本研究为如何在发音障碍患者的交流障碍诊断中结合实验严谨性和临床要求提供了线索。
