一种数字前馈式有源降噪耳罩系统研究

传统耳罩利用隔声原理降低噪声,一般在高频段有着良好的降噪性能,但由于耳罩体积和重量的限制,针对700 Hz以下低频段噪声的降噪性能较差。引入基于滤波-X最小均方(Filter-X Least Mean Square,FXLMS)算法的前馈式有源降噪技术,将有效克服该缺点,使耳罩在低频范围取得良好的降噪性能。实验结果与分析表明,设计的基于STM32控制器的数字前馈式有源降噪耳罩对1 000 Hz以下窄带噪声有15~25 d B的降噪效果。

Research on a digital feedforward active noise reduction headset system

Traditional headset uses sound insulation principle to reduce ambient noise. This way generally has a good noise reduction performance in the high frequency section, but for low frequency signals below 700 Hz it is poor, because of the size and weight limit of the headset. The active noise reduction technique based on FXLMS algorithm is introduced to overcome the disadvantage of the traditional headset and achieve good noise reduction performance in low frequency range. Experimental results and analysis show that the digital feedforward active headset based on STM32 platform can get 15~20 dB noise reduction effect in the 50~1 000 Hz range.