UCLA School of Medicine, 31-24 Rehabilitation Center, 1000 Veteran Avenue, Los Angeles, California 90095-1794, USA.
J Acoust Soc Am. 2023 Oct 1;154(4):2462-2475. doi: 10.1121/10.0021879.
The goal of this computational study is to quantify global effects of vocal tract constriction at various locations (false vocal folds, aryepiglottic folds, pharynx, oral cavity, and lips) on the voice source across a large range of vocal fold conditions. The results showed that while inclusion of a uniform vocal tract had notable effects on the voice source, further constricting the vocal tract only had small effects except for conditions of extreme constriction, at which constrictions at any location along the vocal tract decreased the mean and peak-to-peak amplitude of the glottal flow waveform. Although narrowing in the epilarynx increased the normalized maximum flow declination rate, vocal tract constriction in general slightly reduced the source strength and high-frequency harmonic production at the glottis, except for a limited set of vocal fold conditions (e.g., soft, long vocal folds subject to relatively high pressure). This suggests that simultaneous laryngeal and vocal tract adjustments are required to maximize source-filter interaction. While vocal tract adjustments are often assumed to improve voice production, our results indicate that such improvements are mainly due to changes in vocal tract acoustic response rather than improved voice production at the glottis.
本计算研究的目的是量化在各种声门条件下，在不同位置（假声带、会厌皱襞、咽、口腔和嘴唇）对声道收缩对声源的整体影响。结果表明，尽管包含均匀声道对声源有显著影响，但进一步收缩声道除了在极端收缩条件下，只有很小的影响，在这种条件下，声道的任何位置的收缩都会降低声门波的平均和峰峰值幅度。虽然会厌的变窄会增加归一化最大流量下降率，但声道的收缩通常会稍微降低声门处的源强度和高频谐波产生，除了有限的一组声带条件（例如，柔软、长的声带受到相对较高的压力）。这表明需要同时进行喉和声道的调整以最大化源滤波器的相互作用。虽然声道的调整通常被认为可以改善发声，但我们的结果表明，这种改善主要是由于声道的声学响应的变化，而不是在声门处改善发声。
