Tjaden Kris, Wilding Gregory E
Department of Communicative Disorders and Sciences, University at Buffalo, Buffalo, NY 14214-3005, USA.
J Speech Lang Hear Res. 2004 Aug;47(4):766-83. doi: 10.1044/1092-4388(2004/058).
Both rate reduction and increased loudness reportedly are associated with an increase in the size of the articulatory-acoustic working space and improved acoustic distinctiveness for speakers with dysarthria. Improved intelligibility also has been reported. Few studies have directly compared rate and loudness effects for speakers with dysarthria, however, although rate reduction and increasing vocal loudness are common treatment techniques. In the current study, 15 speakers with dysarthria secondary to multiple sclerosis, 12 speakers with dysarthria secondary to Parkinson's disease (PD), and 15 healthy controls read a passage in habitual, loud, and slow conditions. Rate and loudness variations were elicited using magnitude production. Acoustic measures included articulatory rate, sound pressure level, vowel space area, first moment difference measures, and F2 trajectory characteristics for diphthongs. Ten listeners scaled intelligibility for reading passages produced by the speakers with dysarthria. Relationships between intelligibility estimates and acoustic measures were determined by regression analysis. All speaker groups reduced articulatory rate for the slow condition and increased vocal intensity for the loud condition, relative to the habitual condition. Vowel acoustic distinctiveness, as indexed by vowel space area, was maximized in the slow condition, but stop consonant acoustic distinctiveness, as indexed by first moment difference measures, was maximized in the loud condition. F2 slope measures for diphthongs were not consistently affected by rate or loudness. Scaled intelligibility for speakers with PD also improved in the loud condition relative to both the habitual and slow conditions. Intelligibility estimates for speakers with dysarthria, however, were not strongly related to acoustic measures of supraglottal behavior. Findings are compared with previous studies, and hypotheses for future treatment studies are discussed.
据报道，语速降低和响度增加均与构音障碍患者的发音 - 声学工作空间增大以及声学辨识度提高有关。也有报道称可提高可懂度。然而，尽管语速降低和提高音量是常见的治疗技术，但很少有研究直接比较构音障碍患者的语速和响度效果。在本研究中，15名继发于多发性硬化症的构音障碍患者、12名继发于帕金森病（PD）的构音障碍患者以及15名健康对照者在习惯、大声和慢速条件下朗读一篇文章。使用量级生成法引发语速和响度变化。声学测量包括发音速率、声压级、元音空间面积、一阶矩差测量以及双元音的F2轨迹特征。10名听众对构音障碍患者朗读文章的可懂度进行评分。通过回归分析确定可懂度估计值与声学测量之间的关系。相对于习惯条件，所有说话者组在慢速条件下均降低了发音速率，在大声条件下均提高了声音强度。以元音空间面积为指标的元音声学辨识度在慢速条件下最大，但以一阶矩差测量为指标的塞音声学辨识度在大声条件下最大。双元音的F2斜率测量并未始终受到语速或响度的影响。相对于习惯条件和慢速条件，PD患者在大声条件下的可懂度评分也有所提高。然而，构音障碍患者的可懂度估计值与声门上行为的声学测量之间并无强烈关联。将研究结果与先前的研究进行比较，并讨论了未来治疗研究的假设。
