运用MEMS麦克风对噪声测量系统的设计

Design of Noise Measurement System Using MEMS Microphone

传统声级计的传声器都采用驻极体电容式麦克风,它存在频率响应和噪声特性不理想的缺陷,不仅时间和温度的稳定性较差,还需要提供高性能的前置放大器。MEMS麦克风各项性能高于传统麦克风,且体积很小,有更好的易用性和更大的设计自由度。故提出了运用MEMS麦克风对噪声测量系统的设计。介绍了噪声测量的原理,论述了噪声测量系统的硬件和软件设计理论,并给出软件设计的流程图,进行了实验数据对比。由结果得出:使用该系统不仅能够准确地测量噪声声级,而且该系统结构简单,需要的硬件数量少,可以大大地降低成本。

The electret condenser microphone(ECM)is used in the microphone for traditional sound level meter,poor frequency response and noise performance exist in it,the stability of the temperature and time is also poor.It also needs to be equipped with high performance preamplifier.The performance of MEMS microphone is higher than the performance of the traditional microphone,its volume is smaller and its usability and design freedom are better.So this paper presents the design of the noise measurement system based on the MEMS microphone,introduces the principle of the noise measurement,discusses its hardware and software design theory,and gives the flow chart of the software design,and then,compares the experimental data.Experimental results indicate that this system is not only used to accurately measure the noise level,but also its structure is simple,the lass hardwares are needed and its cost can be reduced greatly.