Mitigation of temporal aliasing via harmonic modeling of laryngeal waveforms in high-speed videoendoscopy
Mitigation of temporal aliasing via harmonic modeling of laryngeal waveforms in high-speed videoendoscopy
复制标题
DOI：
10.1121/1.4742730
复制
发表时间：
2012-09-01
影响因子：
2.4
通讯作者：
McWhorter, Andrew J.
中科院分区：
文献类型：
--
作者：
Ikuma, Takeshi;Kunduk, Melda;McWhorter, Andrew J.
高速视频内窥镜（HSV）通过以高帧速率捕获喉部图像来观察和测量声带的振动行为。然而，商业上可获得的HSV的帧速率仍然限于执行基于样本的时域客观分析。为了减轻由此产生的时间分辨率的缺乏，现有的研究采用谐波和参数模型来评估时间的声叠行为。本文重点介绍了HSV的其他弱点：其固有的时间混淆的敏感性。当HSV摄像机的奈奎斯特频率以上存在大量谐波时，就会发生混叠，而摄像机几乎没有提供任何方法来滤除这些谐波。虽然HSV数据中的混叠效应对许多喉部客观参数测量的影响最小，但是一些参数（诸如谐波噪声比和基于导数的参数）对混叠内容敏感。使用具有仔细选择的谐波数量的参数模型使得能够将混叠谐波分类为谐波信号的一部分。声门区波形的例子来说明建模能力的情况下，正常和紊乱的声带。(C)2012年美国声学学会。[http：//dx.doi.org/10.1121/1.4742730]
High-speed videoendoscopy (HSV) enables the observation and measurement of vibratory behaviors of vocal folds by capturing the laryngeal imagery at high frame rates. The frame rates of commercially available HSVs, however, are still limited to carry out sample-based time-domain objective analyses. To mitigate the resulting lack of temporal resolution, existing studies have employed sum-of-harmonics parametric models to evaluate temporal vocal-fold behaviors. This paper focuses on the other weakness of HSV: its inherent susceptibility to temporal aliasing. Aliasing occurs when there are substantial harmonics above the Nyquist frequency of the HSV camera, and video cameras offer very little means to filter out these harmonics. Although the aliasing effect in HSV data minimally affects many of the laryngeal objective parameter measurements, some parameters, such as harmonics-to-noise ratio and derivative-based parameters, are sensitive to the aliased content. The use of a parametric model with a careful selection of the number of harmonics enables classification of the aliased harmonics as a part of the harmonic signal. Glottal area waveform examples are included to illustrate the modeling capability for cases of normal and disordered vocal folds. (C) 2012 Acoustical Society of America. [http://dx.doi.org/10.1121/1.4742730]