An analysis is made of the fluid-structure interactions involved in the production of voiced speech. It is usual to avoid time consuming numerical simulations of the aeroacoustics of the vocal tract and glottis by the introduction of Fant's 'reduced complexity' equation for the glottis volume velocity Q (G. Fant, Acoustic Theory of Speech Production, Mouton, The Hague 1960). A systematic derivation is given of Fant's equation based on the nominally exact equations of aerodynamic sound. This can be done with a degree of approximation that depends only on the accuracy with which the time-varying flow geometry and surface-acoustic boundary conditions can be specified, and replaces Fant's original 'lumped element' heuristic approach. The method determines all of the effective 'source terms' governing Q. It is illustrated by consideration of a simplified model of the vocal system involving a self-sustaining single-mass model of the vocal folds, that uses free streamline theory to account for surface friction and flow separation within the glottis. Identification is made of a new source term associated with the unsteady vocal fold drag produced by their oscillatory motion transverse to the mean flow.

中文翻译：

---

关于广义 Fant 方程


对有声语音产生中涉及的流体-结构相互作用进行了分析。通常通过引入 Fant 的声门音量速度 Q 的“简化复杂性”方程来避免耗时的声道和声门气动声学数值模拟（G. Fant，语音产生的声学理论，Mouton，海牙 1960 ）。基于名义上精确的空气动力学声音方程，给出了Fant方程的系统推导。这可以通过一定程度的近似来完成，该近似仅取决于可以指定时变流动几何形状和表面声学边界条件的精度，并取代了 Fant 最初的“集总元素”启发式方法。该方法确定了控制 Q 的所有有效“源项”。它通过考虑发声系统的简化模型来说明，该模型涉及声带的自持单质量模型，该模型使用自由流线理论来解释表面声门内的摩擦和流动分离。识别与由声带横向于平均流的振荡运动产生的不稳定声带阻力相关的新源项。