Performance Assessments of Fir versus Iir Models in Acoustic Echo Cancellation

The adequateness of IIR models for acoustic echo cancellation is a long standing question and the answers found in the literature are connicting. We use results from rational Hankel norm and least-squares approximation and we recall a test which provides a priori performance levels for FIR and IIR models. We apply this test to measured acoustic impulse responses. Upon comparing the performance levels of equal complexity FIR and IIR models, we do not observe any signiicant gain from the use of IIR models. We attribute this phenomenon to the shape of the energy spectra of the acoustic impulse responses, so tested, which possess many strong and sharp peaks. Faithful modelling of these peaks requires many parameters irrespective of the type of the model.