The use of time algorithms for the realization of an active sound attenuation

The authors consider a characterization method and an adaptive time algorithm used for the evaluation and optimization, respectively, of the required IIR (infinite impulse response) filter coefficients in an active noise control system. A broadband noise attenuation of up to 20 dB was experimentally achieved by these methods, using a controller consisting of an ADSP 2100 digital signal processor. The approach leads to integration of the feedback control within the controller