Xue Wei, van Hout Roeland, Cucchiarini Catia, Strik Helmer
Centre for Language and Speech Technology (CLST), Radboud University, Erasmusplein 1, 6525HT Nijmegen, the Netherlands.
Centre for Language Studies (CLS), Radboud University, Erasmusplein 1, 6525HT Nijmegen, the Netherlands.
J Commun Disord. 2023 Mar-Apr;102:106301. doi: 10.1016/j.jcomdis.2023.106301. Epub 2023 Jan 25.
Speech intelligibility is an important indicator of the degree of speech impairment in pathological speech. Articulation, as a key feature of dysarthria, has been found to be a stronger contributor to intelligibility of dysarthric speech compared to voice quality, nasality, and prosody. In fact, therapy addressing articulation is often used by speech-language pathologists. Since phoneme-level measures are more directly related to articulation, they may contribute to better evaluating articulation imprecision in speakers with dysarthria and to monitoring the effectiveness of therapy.
We collected two types of phoneme-level measures: a) Accuracy of Phonemes, the percentage of correctly transcribed phonemes, and b) Phonetic Distance, from orthographic transcriptions obtained from expert raters in two types of speech materials (i.e., meaningful sentences and word lists). We first examined the measures' interrater reliability using Generalizability Theory. Then we studied the validity of the measures by correlating them to three criterion variables. Following this, we explored their ability in distinguishing speakers in two classification tasks according to speakers' types (i.e., healthy vs dysarthric) and their severity levels of dysarthria, respectively.
The results showed that both types of phoneme-level measures are highly reliable and valid in two different speech materials. They also showed acceptable results for both classification tasks in different speech materials, with word lists performing better than meaningful sentences. The differences between the two speech materials may be largely caused by differences in word structures and contextual cues in the materials.
The results indicate that both types of phoneme-level measures show largely similar reliability and validity in both speech materials. These measures perform better in word lists than in meaningful sentences, suggesting an advantage for using word lists in clinical practice and research. On the other hand, meaningful sentences can be used for classifying healthy and dysarthric speakers. Our results suggest that using different speech materials gives a better overview of the speakers' intelligibility at the segmental level and the implications of their articulation impairments.
言语可懂度是病理性言语中言语损伤程度的重要指标。构音作为构音障碍的一个关键特征，已发现与构音障碍性言语的可懂度相比，其对嗓音质量、鼻音和韵律的影响更大。事实上，言语治疗师经常采用针对构音的治疗方法。由于音素层面的测量与构音更直接相关，它们可能有助于更好地评估构音障碍患者的构音不精确性，并监测治疗效果。
我们收集了两种音素层面的测量指标：a）音素准确性，即正确转录音素的百分比；b）语音距离，来自于从两种言语材料（即有意义的句子和单词列表）的专家评分者处获得的正字法转录。我们首先使用概化理论检验了测量指标的评分者间信度。然后，通过将这些测量指标与三个标准变量相关联，研究了它们的效度。在此之后，我们分别根据说话者的类型（即健康与构音障碍）及其构音障碍的严重程度，在两个分类任务中探索了它们区分说话者的能力。
结果表明，两种音素层面的测量指标在两种不同的言语材料中都具有高度的可靠性和效度。它们在不同言语材料的两个分类任务中也都显示出可接受的结果，单词列表的表现优于有意义的句子。两种言语材料之间的差异可能在很大程度上是由材料中单词结构和语境线索的差异造成的。
结果表明，两种音素层面的测量指标在两种言语材料中都显示出大致相似的可靠性和效度。这些测量指标在单词列表中的表现优于有意义的句子，这表明在临床实践和研究中使用单词列表具有优势。另一方面，有意义的句子可用于对健康和构音障碍的说话者进行分类。我们的结果表明，使用不同的言语材料能够更好地从音段层面了解说话者的可懂度及其构音损伤的影响。
