REFERENCE SIGNAL GENERATION FOR BROADBAND ANC SYSTEMS IN REVERBERANT ROOMS

One major issue of implementing broadband active noise control systems in reverberant rooms is the lack of reference signals. In this work, by exploiting the spatial sound field characteristics, a time-domain sound field separation method is developed to generate the reference signal for broadband active noise control systems in reverberant rooms. The time-domain sound field separation method separates the outgoing field produced by the primary source from the secondary source feedback and room reverberation on a spherical array, based on spherical harmonic decomposition of the sound field and the radial particle velocity measured by the array. Both the effectiveness of the time-domain sound field separation method and the applicability of the separated outgoing field as the reference signal for a broadband active noise control system in a reverberant room are demonstrated by simulations.