中文摘要：

为了解决管道有源噪声控制中声反馈造成的系统复杂度和计算量的增加，文中引入参量阵扬声器作为次级声源，利用其强指向性减小控制系统的声反馈。为了验证该方法可行性，本文分别在直管和L管中，对600Hz单频噪声和频率范围为500Hz-1000Hz的窄带噪声进行了管道有源噪声控制，同时测量了参量阵扬声器的管内声场和降噪范围。结果表明，参量阵扬声器声反馈小，在没有声反馈补偿的条件下对单频噪声的降噪效果基本达到了声反馈补偿条件下普通扬声器的降噪效果，对窄带噪声的降噪效果稍差。此外，通过测量管道声场和降噪量，确定了参量阵扬声器的降噪区域为误差传感器下游整个管道，降噪面积为管道整个截面。这说明参量阵扬声器作为次级声源降低了系统的复杂度和算法的计算量，并取得了较好的降噪效果。

英文摘要：

To solve the problem that the acoustic feedback raise the complexity of the system and computation of algorithms in active noise control （ANC） of ducts, the parametric array loudspeakers were introduced as the secondary source in this paper. The high directivity sound beam reduced the acoustic feedback of parametric array loudspeakers. To verify the method, experiments of parametric array loudspeakers in ANC of straight and L-type ducts have been conducted for 600 Hz single-tone noise and 500 Hz-1000 Hz narrow-band noise. The experimental results show that the parametric array speakers have a smaller acoustic feedback. Without feedback compensation, the noise reduction of single-tone noise is comparable with loudspeakers, whereas the attenuation amount of the narrow-band noise is less. Furthermore, by measuring sound field of the duct and noise attenuation, the reduction regions were identified to be the entire downstream from error microphone, and the reduction areas were the entire transverse sections of the duct. The experiments demonstrate that the performance of complexity of the system and computation of algorithms has loudspeakers were used as the secondary source. noise cancellation is remarkable and the been reduced, when the parametric array