现有的材料吸声系数测量方法主要有混响室法和驻波管法,都属于实验室测量方法,不适合现场测量。使用普通扬声器的反射法可以对材料的吸声特性进行现场测量,但是对材料尺寸和测试环境有较高的要求。本文利用参量阵非线性自解调可听声的高指向性和在阵长距离内的平面波特性,结合传递函数法,测量材料的吸声系数,并与传统驻波管测量结果进行了对比。结果表明在普通房间条件下,不需要驻波管,混响室等实验环境,即可对小尺寸的材料进行吸声系数的现场快速测量,具有较大的实用性。 The existing material sound absorption coefficient measurement methods are mainly reverberation chamber method and standing wave tube method, all belong to the laboratory measurement method, not suitable for on-site measurement. The use of ordinary speaker reflection method can be on-site measurement of the sound absorption properties of materials, but the material size and test environment have higher requirements. In this paper, the high directivity of the audible sound of parametric array self-demodulation and the plane wave characteristics over a long distance of the array are investigated. The absorption coefficient of the material is measured by the transfer function method, and the results are compared with those of the traditional standing wave tube. The results show that under the condition of normal room, it is more practical to measure the sound absorption coefficient of small size in the field without the need of standing wave tube, reverberation room and other experimental environment.