The use of FIR and IIR adaptive filtering algorithms in the active control of acoustic noise

The role of gradient-based FIR (finite impulse response) and IIR (infinite impulse response) adaptive algorithms as candidates for adapting an active controller for acoustic noise where there is acoustic feedback from secondary source to detector is examined. It is shown that the use of the common algorithms without modification is equivalent to making some fairly sweeping approximations. Nevertheless, simulations show that such systems may work well, though not necessarily achieving the maximum attenuation available