一、引言人耳难以辨别小于1分贝声级的事实并未影响对提高精度声字测量的需要。为了达到定量的目的,如验证飞机适合噪声管理规程,需要测量的准确度为0.1～0.2分贝。因此采用实验室标准传声器(副基准)的准确度比用来校准的装置高一个数量级,即准确度为0.01～0.02分 I. INTRODUCTION The fact that it is difficult for human ear to distinguish between sound levels of less than 1 dB does not affect the need for sound-measurement to improve accuracy. For quantitative purposes, such as verifying the suitability of aircraft for noise management procedures, the accuracy of the measurements required is 0.1 to 0.2 dB. Therefore, the accuracy of using a laboratory standard microphone (sub-standard) is one order of magnitude higher than that of a device used for calibration, that is, the accuracy is 0.01 to 0.02