Rehabilitation Department, Université Laval, Québec City, Québec, Canada.
CHU de Québec, Québec City, Canada.
Am J Speech Lang Pathol. 2021 Jun 18;30(3S):1410-1428. doi: 10.1044/2021_AJSLP-20-00157. Epub 2021 Mar 30.
Purpose Studies have reported that clear speech has the potential to influence suprasegmental and segmental aspects of speech, in both healthy and dysarthric speakers. While the impact of clear speech has been studied on the articulation of individual segments, few studies have investigated its effects on coarticulation with multisegment sequences such as fricative-vowel. Objectives The goals of this study are to investigate, in healthy and dysarthric speech, the impact of clear speech on (a) the perception of anticipatory vowel coarticulation in fricatives and (b) the acoustic characteristics of this effect. Method Ten speakers with dysarthria secondary to idiopathic Parkinson's disease were recruited as well as 10 age- and sex-matched healthy speakers. A sentence reading task was performed in natural and clear speaking conditions. The sentences contained words with the initial fricatives /s/ and /ʃ/ preceded by /ə/ and followed by the vowels /i/, /y/, /u/, or /a/. For the perceptual measurements, five listeners were recruited and were asked to predict the upcoming word by listening only to the isolated fricative. Acoustic analyses consisted of spectral moment analysis (M1-M4) on averaged time series. Results Perceptual findings report that identification rates were improved with clear speech for the speakers with dysarthria, but only for the fricative-/i/ sequences. Error pattern analysis indicates that this improvement is associated with an increase in the roundness parameter (lip spreading) identification. Acoustic results are unclear for M1 and M3 but suggest that M2 and M4 differentiation between the rounded versus unrounded vowel contexts is increased with clear speech for the speakers with dysarthria. Discussion Taken together, these findings suggest that clear speech may improve lip coordination in dysarthric speakers with Parkinson's disease. However, the impact of clear speech on the acoustic measures of fricative spectral moments is somewhat limited. This suggests that these metrics, when taken individually, do not capture the entire complexity of fricative-vowel coarticulation.
目的 已有研究报告称，清晰语音有可能影响健康和构音障碍者的语音超音段和音段特征。虽然已经研究了清晰语音对单个音段发音的影响，但很少有研究调查其对摩擦-元音等多音节序列协同发音的影响。
方法 招募了 10 名患有特发性帕金森病导致的构音障碍的患者和 10 名年龄和性别匹配的健康对照者。他们在自然和清晰两种说话条件下完成句子朗读任务。句子中包含以 /ə/ 开头、以 /i/、/y/、/u/ 或 /a/ 结尾的单词，其首辅音为 /s/ 和 /ʃ/。对于感知测量，招募了 5 名听众，要求他们仅通过听孤立的摩擦音来预测接下来的单词。声学分析包括平均时间序列上的谱矩分析（M1-M4）。
结果 感知研究结果表明，与自然说话相比，构音障碍者的识别率在清晰说话时有所提高，仅在摩擦音-/i/序列中如此。错误模式分析表明，这种改善与圆唇度参数（唇展开）识别的增加有关。M1 和 M3 的声学结果尚不清楚，但表明对于构音障碍者，M2 和 M4 可以区分圆唇和非圆唇元音语境，且这种区分在清晰说话时有所增强。
讨论 总之，这些发现表明，清晰语音可能会改善帕金森病构音障碍者的唇协调能力。然而，清晰语音对摩擦音频谱矩的声学测量的影响有些有限。这表明这些指标单独使用时并不能捕捉到摩擦-元音协同发音的全部复杂性。
