Proper location of the transducers for an active noise barrier

Abstract

The main intention of this study is to propose general criteria for the locations of the control sources and error microphones that improve the performance of the active noise barrier. Based on the proposed criteria of this study, the greater reduction is attained when the diffracted field of the noise source is canceled with the diffracted field of the control sources, that is, it is suggested to locate the control sources on the incident side and below the path that connects the furthest point in the shadow zone to the edge of the barrier. Furthermore, it is suggested that the error microphones are most suitably placed on the shadow side of the barrier where they are under the diffracted field of both the primary and control sources. The results also show that with these general criteria, the active noise control achieves an extra reduction that varies from 14.9 to 3.9 dB (for the one-third octave bands from 63 Hz to 1 kHz) and 9.3 dB for the broadband noises.

Using genetic algorithms to optimize the location of transducers for an active noise barrier

“…where Z P is the vector of complex acoustic transfer impedances of the primary source with a strength of q P , and Z s is an M × N matrix, corresponds to the transfer impedance matrix of N control sources at the positions of M points. In equation (6), q s denotes the vector of the complex strength of the control source, 26 and is determined by minimizing the total squared pressure at the error microphones. The total squared acoustic pressure is expressed in equation ( 7)…”

“…Research has shown that active noise control significantly enhances the performance of acoustic barriers at low-frequency noise bands. [1][2][3][4] Despite the existence of various parameters that affect the efficiency of active noise barriers, few studies have optimized them. [5][6][7] Some of these parameters include the number, location, and distance between adjacent control sources and error microphones.…”

“…[1][2][3][4] Despite the existence of various parameters that affect the efficiency of active noise barriers, few studies have optimized them. [5][6][7] Some of these parameters include the number, location, and distance between adjacent control sources and error microphones. Previous investigations have typically examined the impact of these parameters separately.…”

“…Previous studies have focused on improving the performance of active noise barriers by examining only a few configurations or variables. Sohrabi et al 11,12 addressed this issue by systematically calculating the insertion loss for numerous candidate positions of control sources and error microphones in an infinite active noise barrier. They found that the active noise control system is more efficient when control sources are placed at the incident side and below the top edge of the barrier, and error microphones are located in barrier’s the shadow zone.…”

Circular active noise barrier using theoretical control filter considering interaction between speaker and barrier

“…By placing speakers and error microphones above the barrier, the diffracted noise in a low-frequency band is reduced through ANC. The arrangement of microphones and speakers 8 , 9 , the method of obtaining the control filter 10 , 11 , and using unidirectional control sources 12 have been studied to improve the performance of the active noise barrier. However, the active noise barrier using semi-infinite barrier is expensive and requires a large place to set up.…”