The sound absorption coefficient of the material was tested by standing wave tube method. 采用驻波管法测试材料的吸声系数。
There are some parameters that influence the multilayer microperfrated structure, which make acoustic impedance and absorption cofficient to compute complicatedly. 摘要影响双层微穿孔结构的参数很多，其声阻抗及吸声系数的计算复杂。
