INTERPRETATION OF BIOMECHANICAL SIMULATIONS OF NORMAL AND CHAOTIC VOCAL FOLD OSCILLATIONS WITH EMPIRICAL EIGENFUNCTIONS
INTERPRETATION OF BIOMECHANICAL SIMULATIONS OF NORMAL AND CHAOTIC VOCAL FOLD OSCILLATIONS WITH EMPIRICAL EIGENFUNCTIONS
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DOI：
10.1121/1.409875
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发表时间：
1994-06-01
影响因子：
2.4
通讯作者：
KRISCHER, K
中科院分区：
文献类型：
--
作者：
BERRY, DA;HERZEL, H;KRISCHER, K
从正常和混沌声带振荡的生物力学模拟中提取经验正交特征函数。对于正常发声，两个主要的经验特征函数捕捉褶皱的振动模式，并表现出1:1的夹带。本征函数与简化的三维弹性连续体的理论低阶正态模态和线性化的双质量模型的正态模态有一定的对应关系。特征函数还有助于对声带动力学中能量传递机制的物理解释。在松散覆盖的模拟过程中观察到次谐波状态和混沌振荡，在这种情况下，至少需要三个经验特征函数来捕获由此产生的声带振荡。这些混沌振荡可以理解为一些低阶模式的不同步，并且可能与声音吱吱或声带损伤的机制有关。此外，在复杂振荡期间捕获的一些经验特征函数对应于早期理论工作中描述的高阶正态模态。经验特征函数也可用于设计低阶模型（在经验特征函数保持或多或少恒定的范围内有效），并有助于促进生物力学模拟的分岔分析。
Empirical orthogonal eigenfunctions are extracted from biomechanical simulations of normal and chaotic vocal fold oscillations. For normal phonation, two dominant empirical eigenfunctions capture the vibration patterns of the folds and exhibit a 1:1 entrainment. The eigenfunctions show some correspondence to theoretical low-order normal modes of a simplified, three-dimensional elastic continuum, and to the normal modes of a linearized two-mass model. The eigenfunctions also facilitate a physical interpretation of energy transfer mechanisms in vocal fold dynamics. Subharmonic regimes and chaotic oscillations are observed during simulations of a lax cover, in which case at least three empirical eigenfunctions are necessary to capture the resulting vocal fold oscillations. These chaotic oscillations might be understood in terms of a desynchronization of a few of the low-order modes, and may be related to mechanisms of creaky voice or vocal fry. Furthermore, some of the empirical eigenfunctions captured during complex oscillations correspond to higher-order normal modes described in earlier theoretical work. The empirical eigenfunctions may also be useful in the design of lower-order models (valid over the range for which the empirical eigenfunctions remain more or less constant), and may help facilitate bifurcation analyses of the biomechanical simulation.