高速摄影成像分析声带振动发声的前后不对称性

高速摄影成像直接观察到声带振动的前后不对称性。将11个离体狗喉声带进行发声实验,设置3组声门下压分别为10 cm H₂O,20 cm H₂O和30 cm H₂O,利用高速摄像仪和传声器,分别记录不同声门下压的声带振动图像和声信号.对高速摄影成像与同步采集的声信号基频进行定量分析和比较,基频均随声门下压的增大而增加。此外,对两种测量方法得到的基频进行相关分析比较,得到在同一声门下压下两种方法的基频相关系数均大于0.9,表明高速摄影成像得到的基频与声信号的基频具有高度相关性。高速摄影成像能直观地测量声带振动行为,对研究声带振动发声机理提供了有价值的测量手段。高速摄影获得的声带线性结构上25%,50%,75%位置处的振动幅度,显示了声带前后振动不对称且声门下压较低时振动不对称较明显。 

High-speed imaging analysis of anterior-posterior asymmetry of vocal fold vibration

High-speed imaging directly observed the anterior-posterior asymmetry of vocal fold vibration. This study performed quantitative analysis and comparison to the fundamental frequency measured by high-speed imaging and sound recording in 11 excised canine larynges. Three sets of subglottal pressure, including 10 cmH₂O, 20 cmH₂O, and 30 cmH₂O were applied. Using Lagrange interpolation and Canny image edge detection, the glottal area time series was obtained, and then the vibratory fundamental frequency was derived. The fundamental frequency increased with the subglottal pressure. The correlation relationship between the fundamental frequencies obtained by these two measurement methods had been investigated and the correlation coefficient above 0.9 was found, indicating the high correlation. Therefore, the results have shown that high-speed imaging technology could direct measure vocal fold vibration and provide valuable tool to reveal physical mechanisms of laryngeal activities. The vibration amplitudes of the vocal fold linear structure 25%, 50%, 75% locations show that vocal fold vibration is anterior-posterior asymmetry and the asymmetry vibration is more apparent under low subglottal pressure.