Howe M S, McGowan R S
Boston University, College of Engineering, 110 Cummington Street, Boston MA 02215.
J Sound Vib. 2011 Jun 20;330(13):3123-3140. doi: 10.1016/j.jsv.2011.01.017.
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.
本文对浊音语音产生过程中涉及的流固相互作用进行了分析。通常，通过引入用于声门体积速度Q的方特“简化复杂度”方程（G. 方特，《语音产生的声学理论》，穆顿出版社，海牙，1960年），来避免对声道和声门的气动声学进行耗时的数值模拟。基于名义上精确的气动声学方程，对方特方程进行了系统推导。这样做可以达到一定程度的近似，该近似仅取决于时变流动几何形状和表面声学边界条件的指定精度，并且取代了方特原来的“集总元件”启发式方法。该方法确定了所有控制Q的有效“源项”。通过考虑一个简化的发声系统模型来说明这一点，该模型涉及声带的自持单质量模型，它使用自由流线理论来考虑声门内的表面摩擦和流动分离。识别出了一个与声带横向于平均流的振荡运动产生的非稳态声带阻力相关的新源项。
