Patel Rita R, Unnikrishnan Harikrishnan, Donohue Kevin D
Department of Speech & Hearing Sciences, Indiana University, Bloomington, Indiana, United States of America.
Department of Electrical and Computer Engineering, University of Kentucky, Lexington, Kentucky, United States of America.
PLoS One. 2016 Apr 28;11(4):e0154586. doi: 10.1371/journal.pone.0154586. eCollection 2016.
The goal of this study is to quantify the effects of vocal fold nodules on vibratory motion in children using high-speed videoendoscopy. Differences in vibratory motion were evaluated in 20 children with vocal fold nodules (5-11 years) and 20 age and gender matched typically developing children (5-11 years) during sustained phonation at typical pitch and loudness. Normalized kinematic features of vocal fold displacements from the mid-membranous vocal fold point were extracted from the steady-state high-speed video. A total of 12 kinematic features representing spatial and temporal characteristics of vibratory motion were calculated. Average values and standard deviations (cycle-to-cycle variability) of the following kinematic features were computed: normalized peak displacement, normalized average opening velocity, normalized average closing velocity, normalized peak closing velocity, speed quotient, and open quotient. Group differences between children with and without vocal fold nodules were statistically investigated. While a moderate effect size was observed for the spatial feature of speed quotient, and the temporal feature of normalized average closing velocity in children with nodules compared to vocally normal children, none of the features were statistically significant between the groups after Bonferroni correction. The kinematic analysis of the mid-membranous vocal fold displacement revealed that children with nodules primarily differ from typically developing children in closing phase kinematics of the glottal cycle, whereas the opening phase kinematics are similar. Higher speed quotients and similar opening phase velocities suggest greater relative forces are acting on vocal fold in the closing phase. These findings suggest that future large-scale studies should focus on spatial and temporal features related to the closing phase of the glottal cycle for differentiating the kinematics of children with and without vocal fold nodules.
本研究的目的是使用高速视频内镜量化声带小结对儿童振动运动的影响。在20名患有声带小结的儿童（5 - 11岁）和20名年龄及性别匹配的发育正常儿童（5 - 11岁）以典型音高和响度持续发声期间，评估其振动运动的差异。从稳态高速视频中提取声带膜部中点处声带位移的标准化运动学特征。计算了总共12个代表振动运动时空特征的运动学特征。计算了以下运动学特征的平均值和标准差（逐周期变异性）：标准化峰值位移、标准化平均开口速度、标准化平均闭合速度、标准化峰值闭合速度、速度商和开放商。对有声带小结和无声带小结儿童之间的组间差异进行了统计学研究。与嗓音正常的儿童相比，声带小结儿童在速度商的空间特征和标准化平均闭合速度的时间特征方面观察到中等效应量，但经Bonferroni校正后，两组之间的这些特征均无统计学意义。声带膜部位移的运动学分析表明，有小结的儿童与发育正常儿童的主要区别在于声门周期的闭合相运动学，而开放相运动学相似。较高的速度商和相似的开放相速度表明在闭合相有声带受到更大的相对力作用。这些发现表明，未来的大规模研究应关注与声门周期闭合相相关的时空特征，以区分有声带小结和无声带小结儿童的运动学。
