Application of the Parametric Loudspeakers in Active Noise Control

In active noise control system,unidirectional loudspeakers are used as secondary source to reduce the sound pressure levels in the targeted locations.However,the sound pressure levels elsewhere in the sound field is likely to increase.Because of its high direction,the parametric loudspeakers can be used as secondary source in active noise control system to suppress the noise in the targeted points without augment in other areas.In this paper,the comparison of the unidirectional loudspeakers and parametric loudspeakers as secondary sources are made.The results of computer simulations and experiments in the anechoic chamber show that the use of parametric loudspeakers can reduce the sound pressure levels in the designed points without causing increase in other areas.