Lehmann Eric A, Johansson Anders M
Western Australian Telecommunications Research Institute, 35 Stirling Highway, Crawley, WA 6009, Australia.
J Acoust Soc Am. 2008 Jul;124(1):269-77. doi: 10.1121/1.2936367.
A method is proposed that provides an approximation of the acoustic energy decay (energy-time curve) in room impulse responses generated using the image-source technique. A geometrical analysis of the image-source principle leads to a closed-form expression describing the energy decay curve, with the resulting formula being valid for a uniform as well as nonuniform definition of the enclosure's six absorption coefficients. The accuracy of the proposed approximation is demonstrated on the basis of impulse-response simulations involving various room sizes and reverberation levels, with uniform and nonuniform sound absorption coefficients. An application example for the proposed method is illustrated by considering the task of predicting an enclosure's reflection coefficients in order to achieve a specific reverberation level. The technique presented in this work enables designers to undertake a preliminary analysis of a simulated reverberant environment without the need for time-consuming image-method simulations.
提出了一种方法，该方法可对使用镜像源技术生成的房间脉冲响应中的声能衰减（能量-时间曲线）进行近似。对镜像源原理的几何分析得出了一个描述能量衰减曲线的闭式表达式，所得公式对于封闭空间六个吸收系数的均匀和非均匀定义均有效。基于涉及各种房间尺寸和混响水平、具有均匀和非均匀吸声系数的脉冲响应模拟，证明了所提近似方法的准确性。通过考虑预测封闭空间的反射系数以实现特定混响水平的任务，说明了所提方法的一个应用示例。本文提出的技术使设计人员能够对模拟的混响环境进行初步分析，而无需进行耗时的镜像法模拟。
