ARMA processes in sub-bands with application to audio restoration

ABSTRACT It was recently shown [1] that the sub-band signals resulting from the analysis of an ARMA process by a decimating filter bank can be modeled by individual lower-rate ARMA processes, by using the power spectral density concept. This paper discusses the validity of this modeling and the mapping of zeros and poles of the corresponding generator filters along the sub-bands. Based on these results, after some considerations related to the employment of sub-band systems in audio restoration, a sub-band version of a model-based technique for suppression of impulsive noise from audio recordings is proposed. Simulation results are presented and validated by subjective as well as objective means.