Dependence of phonation threshold pressure on vocal tract acoustics and vocal fold tissue mechanics
Dependence of phonation threshold pressure on vocal tract acoustics and vocal fold tissue mechanics
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DOI：
10.1121/1.2173516
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发表时间：
2006-04-01
影响因子：
2.4
通讯作者：
Titze, IR
中科院分区：
文献类型：
--
作者：
Chan, RW;Titze, IR
分析和计算机模拟研究表明，声道的声阻抗和声带组织的粘弹性特性对于确定声带振动的动力学和能量传递机制是至关重要的。在本研究中，通过考虑粘膜波的传播和声门上声道的惯性电抗(惯性)作为流致声带自振荡的主要能量传递机制，修正了线性小幅度振荡理论。具体地说，分析结果预测发声阈值压力(P-TH)随声带的粘性剪切特性而增加，但随声道惯性而减小。这一理论是使用喉部的物理模型进行的经验性验证，在该模型中，将生物材料(脂肪、透明质酸和纤维连接蛋白)植入声带覆盖物，以研究声带组织粘弹性对P-TH的影响。采用声门上均匀管状声道，观察声道惯性对P-TH的影响。结果表明，PTH随声道惯性阻抗的增大而减小，随声带盖的粘性剪切模数(G‘’)或动态粘度(ETA‘)增大而增大，与理论预测一致。这些发现支持了透明质酸作为外科生物植入物修复涉及固有层浅层的声音障碍的潜在生物力学优势，如疤痕、声沟、萎缩和Reinke‘s水肿。(C)2006年美国声学学会。
Analytical and computer simulation studies have shown that the acoustic impedance of the vocal tract as well as the viscoelastic properties of vocal fold tissues are critical for determining the dynamics and the energy transfer mechanism of vocal fold oscillation. In the present study, a linear, small-amplitude oscillation theory was revised by taking into account the propagation of a mucosal wave and the inertive reactance (inertance) of the supraglottal vocal tract as the major energy transfer mechanisms for flow-induced self-oscillation of the vocal fold. Specifically, analytical results predicted that phonation threshold pressure (P-th) increases with the viscous shear properties of the vocal fold, but decreases with vocal tract inertance. This theory was empirically tested using a physical model of the larynx, where biological materials (fat, hyaluronic acid, and fibronectin) were implanted into the vocal fold cover to investigate the effect of vocal fold tissue viscoelasticity on P-th. A uniform-tube supraglottal vocal tract was also introduced to examine the effect of vocal tract inertance on P-th. Results showed that Pth decreased with the inertive impedance of the vocal tract and increased with the viscous shear modulus (G '') or dynamic viscosity (eta') of the vocal fold cover, consistent with theoretical predictions. These findings supported the potential biomechanical benefits of hyaluronic acid as a surgical bioimplant for repairing voice disorders involving the superficial layer of the lamina propria, such as scarring, sulcus vocalis, atrophy, and Reinke's edema. (c) 2006 Acoustical Society of America.