Kim Heejin, Gurevich Naomi
Linguistics, University of Illinois, Urbana-Champaign, Illinois, USA.
Communication Sciences and Disorders, Purdue University Fort Wayne, Fort Wayne, Indiana, USA.
Clin Linguist Phon. 2023 Feb 1;37(2):125-142. doi: 10.1080/02699206.2021.2019312. Epub 2021 Dec 27.
Consonant production errors are common in dysarthric speech, but not all consonants are affected to the same extent. Currently, only limited knowledge exists regarding whether different positional allophones are affected to varying degrees in dysarthric speech. The aim of this study was to investigate the effect of consonants' position-in-words on consonant production accuracy and their relevance to speech intelligibility. To this end, the percentage of correctly articulated consonants was analyzed with respect to position-in-words, manner of articulation, and speakers' overall intelligibility in dysarthric speech secondary to cerebral palsy. Results revealed that consonants were generally more accurate in initial positions than other positions, and when they were singletons rather than clusters. However, fricatives, a category commonly noted for frequent misarticulations, exhibited no significant positional effects, indicating that fricatives were affected to a similar degree across all word positions. In addition, positional asymmetry manifested to a greater degree as intelligibility decreased. Finally, the strength of the relationship between consonant production accuracy and intelligibility varied depending on positions-in-words, with strong correlations in the medial and final cluster positions but no significant correlation for fricatives in the initial and final singleton positions. The correlation was markedly low for the initial consonants, possibly due to the resistance of initial consonants to production errors. The positional asymmetry found in this study necessitates more research on non-initial consonants and clusters for their potential in improving consonant production and speech intelligibility as a part of dysarthria management.
辅音发音错误在构音障碍性言语中很常见，但并非所有辅音受到的影响程度都相同。目前，关于不同位置的音位变体在构音障碍性言语中是否受到不同程度的影响，我们所知有限。本研究的目的是调查辅音在单词中的位置对辅音发音准确性的影响及其与言语可懂度的相关性。为此，我们分析了继发于脑瘫的构音障碍性言语中，辅音在单词中的位置、发音方式以及说话者整体可懂度方面的正确发音百分比。结果显示，辅音在词首位置通常比其他位置更准确，且单独发音时比成簇发音时更准确。然而，摩擦音这一通常被认为发音错误频繁的类别，并未表现出显著的位置效应，这表明摩擦音在所有单词位置受到的影响程度相似。此外，随着可懂度降低，位置不对称性表现得更为明显。最后，辅音发音准确性与可懂度之间关系的强度因辅音在单词中的位置而异，在中间和成簇词尾位置相关性较强，但在词首和词尾单独发音的摩擦音中无显著相关性。词首辅音的相关性明显较低，可能是由于词首辅音对发音错误具有抵抗力。本研究中发现的位置不对称性，需要对非词首辅音和成簇辅音进行更多研究，以探究它们在改善辅音发音和言语可懂度方面的潜力，作为构音障碍管理的一部分。
