一、前言电声学中的精密测量与校准和心理学范围的主观响应的评价都要求有一个自由空间,即在这空间内不会受到附近物体的反射影响。为了保证环境噪声比被测噪声的最低声级更低,四面墙壁能作到完全声吸收,就需要一个消声室。实际上,自由场中要求的反平方律的条件,可以由具有能量吸收为99%和相应的具有0.1 I. INTRODUCTION The evaluation of the precise measurement and calibration in electroacoustics and the subjective response in psychology requires a free space in which the reflections of nearby objects are unaffected. In order to ensure that the ambient noise is lower than the lowest level of the noise under test and that all four walls are completely acoustically absorbed, an anechoic chamber is required. In fact, the condition of the anti-square law required in the free field can be given by a ratio of 99% with energy absorption and correspondingly with 0.1