Title :
Multichannel active control of random noise in a small reverberant room
Author :
Laugesen, Søren ; Elliott, Stephen J.
Author_Institution :
Acoust. Lab., Tech. Univ. of Denmark, Lyngby, Denmark
fDate :
4/1/1993 12:00:00 AM
Abstract :
An algorithm for multichannel adaptive IIR (infinite impulse response) filtering is presented and applied to the active control of broadband random noise in a small reverberant room. Assuming complete knowledge of the primary noise, the theoretically optimal reductions of acoustic energy are initially calculated by means of a frequency-domain model. These results are contrasted with results of a causality constrained theoretical time-domain optimization which are then compared with experimental results, the latter two results showing good agreement. The experimental performances of adaptive multichannel FIR (finite impulse response) and IIR filters are then compared for a four-secondary-source, eight-error microphone active control system, and it is found that for the present application FIR filters are sufficient when the primary noise source is a loudspeaker. Some experiments are then presented with the primary noise field generated by a panel excited by a loudspeaker in an adjoining room. These results show that far better performances are provided by IIR and FIR filters when the primary source has a lightly damped dynamic behavior which the active controller must model
Keywords :
acoustic field; adaptive control; adaptive filters; audio acoustics; digital filters; frequency-domain analysis; loudspeakers; microphones; noise abatement; random noise; reverberation; time-domain analysis; FIR filters; IIR filters; acoustic energy; active control; broadband random noise; causality constrained optimisation; finite impulse response; frequency-domain model; infinite impulse response; loudspeaker; microphone; multichannel adaptive filtering; primary noise source; small reverberant room; sound field; time-domain optimization; Acoustic noise; Active noise reduction; Adaptive control; Adaptive filters; Filtering algorithms; Finite impulse response filter; IIR filters; Loudspeakers; Noise reduction; Programmable control;
Journal_Title :
Speech and Audio Processing, IEEE Transactions on