Connaghan Kathryn P, Patel Rupal
Northeastern University, Boston, MA.
J Speech Lang Hear Res. 2017 Jan 1;60(1):38-50. doi: 10.1044/2016_JSLHR-S-15-0291.
To compare vowel acoustics and intelligibility in words produced with and without contrastive stress by speakers with spastic (mixed-spastic) dysarthria secondary to cerebral palsy (DYSCP) and healthy controls (HCs).
Fifteen participants (9 men, 6 women; age M = 42 years) with DYSCP and 15 HCs (9 men, 6 women; age M = 36 years) produced sentences containing target words with and without contrastive stress. Forty-five healthy listeners (age M = 25 years) completed a vowel identification task of DYSCP productions. Vowel acoustics were compared across stress conditions and groups using 1st (F1) and 2nd (F2) formant measures. Perceptual intelligibility was compared across stress conditions and dysarthria severity.
F1 and F2 significantly increased in stressed words for both groups, although the degree of change differed. Mean Euclidian distance between vowels also increased with stress. The relative probability of vowels falling within the target F1 × F2 space was greater for HCs but did not differ with stress. Stress production resulted in greater listener vowel identification accuracy for speakers with mild dysarthria.
Contrastive stress affected vowel formants for both groups. Perceptual results suggest that some speakers with dysarthria may benefit from a contrastive stress strategy to improve vowel intelligibility.
比较患有继发于脑瘫的痉挛性（混合性痉挛）构音障碍（DYSCP）的说话者和健康对照者（HCs）在有对比重音和无对比重音情况下说出单词时的元音声学特征和可懂度。
15名患有DYSCP的参与者（9名男性，6名女性；年龄中位数M = 42岁）和15名HCs（9名男性，6名女性；年龄中位数M = 36岁）说出包含目标单词的句子，这些单词有对比重音和无对比重音两种情况。45名健康听众（年龄中位数M = 25岁）完成了对DYSCP发音的元音识别任务。使用第一共振峰（F1）和第二共振峰（F2）测量方法，比较了不同重音条件和不同组之间的元音声学特征。比较了不同重音条件和构音障碍严重程度之间的感知可懂度。
两组中，重音单词的F1和F2均显著增加，尽管变化程度有所不同。元音之间的平均欧几里得距离也随着重音而增加。HCs的元音落在目标F1×F2空间内的相对概率更高，但与重音无关。对于轻度构音障碍的说话者，重音发音使听众的元音识别准确率更高。
对比重音对两组的元音共振峰都有影响。感知结果表明，一些构音障碍患者可能受益于对比重音策略来提高元音可懂度。
