Wave-based unsteady acoustic simulation for correction of absorption coefficient in reverberation room

混响室的吸声系数被用于室内声学和噪声控制的实践中。然而，众所周知，测量结果随测量对象的房间形状和测量材料面积的不同而不同。本文采用时域有限元方法对测量声场进行分析。本研究表明，分析测量结果偏差的原因和改进测量的方法是有效的。为了评估用于测量的实际声场，根据分析结果计算入射声能与测量声场所有边界中的入射声能与测试材料的比率。将这些比值与分析得到的混响室中的吸收系数进行了比较，并用它们来修正测量的衰减曲线。

The absorption coefficient in reverberation room is used in the practice of room acoustics and noise controls. However it is well known that measurement results of the coefficient vary according to a room shape of the measurement and area of the measurement material.In this study, sound fields for the measurement are analyzed by time domain finite element method. This study shows effectiveness of the analysis for investigation on causes of variation in the measurement results and improvement methods of the measurement. To evaluate an actual sound field for the measurement, the ratio of incident sound energy to the test material in those to all boundary of the measurement sound field is calculated from results of the analysis. The ratios are compared with the absorption coefficients in reverberation room obtained by the analyses, and are utilized to correct decay curves of the measurement.