近代现场吸声测量技术

A review of modern in-situ sound absorption measurement techniques

驻波管法和混响室法是吸声测量技术中常用的方法,用于现场测量时不满足特殊声场环境假设、样品尺寸、频率限制等。脉冲回波方法和声强测量法对测量环境没有严格要求,适用于现场测量。这类方法的共同特点是在频域处理数据,往往需要将反射波与入射波分离,测量步骤较多,不利于在线测量。参数反演方法直接利用测量的声压时间序列获得声学阻抗或吸声系数,是一种时域测量方法,更适用于在线测量。在声学理论指导下,借助于计算机与数字信号处理技术的研究成果,一些新的测量方法不断被提出,但要成为一种成熟的技术,还有大量的研究工作去做。

Standing wave tube method and reverberation room method, which are two traditional sound absorption measurement methods, are not suitably used for in-situ measurement because of unsatisfying the assumption of perfect sound field, the sample size and frequency limits. Echo-impulse method and sound intensity method are much advantaged for spot measurements due to no strict requirement of measurement conditions. But there are still some disadvantages to restrict the two methods for in-situ use, such as the need of seperating incident and reflect wave and processing data in frequency-domain. An in- novative method, time-do-main parameter estimation method, is suitable for in-situ sound absorption mea- sure-ment. Using time series of sound pressure before and after reflection to estimate impedance parameters of the measured sample can avoid many difficulties from these traditional methods. It is believable that some new methods for in-situ sound absorption measurement will be further proposed with the development of computer and signal processing techeniques. But much investigation need doing before they become the widely accepted methods.