McKenna Victoria S, Hylkema Jennifer A, Tardif Monique C, Stepp Cara E
Department of Speech, Language, & Hearing Sciences, Purdue University, West Lafayette IN.
Department of Speech, Language, and Hearing Sciences, Boston University, MA.
J Speech Lang Hear Res. 2020 Feb 26;63(2):405-420. doi: 10.1044/2019_JSLHR-19-00135. Epub 2020 Feb 4.
Purpose This study examined vocal hyperfunction (VH) using voice onset time (VOT). We hypothesized that speakers with VH would produce shorter VOTs, indicating increased laryngeal tension, and more variable VOTs, indicating disordered vocal motor control. Method We enrolled 32 adult women with VH (aged 20-74 years) and 32 age- and sex-matched controls. All were speakers of American English. Participants produced vowel-consonant-vowel combinations that varied by vowel (ɑ/u) and plosive (p/b, t/d, k/g). VOT-measured at the release of the plosive to the initiation of voicing-was averaged over three repetitions of each vowel-consonant-vowel combination. The coefficient of variation (CoV), a measure of VOT variability, was also computed for each combination. Results The mean VOTs were not significantly different between the two groups; however, the CoVs were significantly greater in speakers with VH compared to controls. Voiceless CoV values were moderately correlated with clinical ratings of dysphonia ( = .58) in speakers with VH. Conclusion Speakers with VH exhibited greater variability in phonemic voicing targets compared to vocally healthy speakers, supporting the hypothesis for disordered vocal motor control in VH. We suggest future work incorporate VOT measures when assessing auditory discrimination and auditory-motor integration deficits in VH.
目的 本研究使用语音起始时间（VOT）来研究嗓音功能亢进（VH）。我们假设患有VH的说话者会产生更短的VOT，这表明喉肌张力增加，并且VOT的变异性更大，这表明嗓音运动控制紊乱。方法 我们招募了32名患有VH的成年女性（年龄在20 - 74岁之间）和32名年龄及性别匹配的对照者。所有参与者均以美式英语为母语。参与者发出由元音（ɑ/u）和爆破音（p/b、t/d、k/g）组合而成的元音 - 辅音 - 元音组合。在每个元音 - 辅音 - 元音组合重复三次的情况下，测量从爆破音释放到发声起始的VOT，并计算其平均值。还针对每个组合计算了变异系数（CoV），它是衡量VOT变异性的指标。结果 两组之间的平均VOT没有显著差异；然而，与对照组相比，患有VH的说话者的CoV显著更高。在患有VH的说话者中，清音CoV值与发音障碍的临床评分呈中度相关（ = 0.58）。结论 与嗓音健康的说话者相比，患有VH的说话者在音素发声目标上表现出更大的变异性，这支持了VH中嗓音运动控制紊乱的假设。我们建议未来在评估VH中的听觉辨别和听觉 - 运动整合缺陷时，应纳入VOT测量方法。
