Sensing strategies for a single screen active noise barrier in open-plan offices

© 2017 Institute of Noise Control Engineering. All rights reserved. Single screen barriers are widely used in open-plan offices to improve acoustical privacy. However, the insertion loss of an indoor passive barrier is limited, especially in the low frequency range. The feasibility of applying active noise control techniques to improve the performance of indoor barriers is investigated in this paper. An analytical model is developed based on the modal expansion method to calculate the low frequency sound field inside the room, and its effectiveness is validated by the finite element method. Using this model, the performance of the active control system for an indoor noise barrier with different near field sensing strategies are compared. It is found that the best performance is achieved by minimizing the sum of the normal active sound intensity at the error sensors, which are placed with a specific layout. The extra noise attenuation at the observation points in this case is almost equivalent to the noise reduction at the error sensors