Investigation of system configuration and pressure gradient control for active noise barrier

Traffic noise-pollution degrades the environmental quality and the public health of populated neighborhoods located along the traffic roads. The high frequency component of this noisepollution can be attenuated by noise barriers and absorbed by air, while the low frequency component remains hard to attenuate due to the nature of diffraction and propagation of sound. Active noise control proves to be very efficient in attenuating low frequency noise. Allied with a noise barrier, this concept is important and worth pursuing further for control of sound at broadband-frequency. However, a major problem with this kind of application is limited by the declined performance when the secondary source away from the primary source when minimizing the sound pressure at the barrier edge in the existing publications. The aim of this study was to evaluate a new configuration of control loudspeakers and error sensors to closely match the primary acoustic-noise characterization behind the barrier generated by sound diffraction. Numerical analysis on its performance is carried out. The results of this study indicate that the improved performance of active noise barrier can be achieved using the new configurations of control loudspeakers and error sensing strategy.