Comparison of three post-filtering algorithms for residual acoustic echo reduction

We consider an acoustic echo control system composed of a short conventional acoustic echo canceller combined with a post-filter in a teleconference context. The post-filter is implemented in an open-loop structure in the frequency domain, which provides good adaptive performance and flexibility for the choice of the post-filter length. Three post-filtering algorithms are compared in terms of residual echo attenuation and near-end speech distortion. The effect of the post-filter length is also examined. Our study confirms that the post-filtering approach provides high residual echo attenuation. Moreover, it appears that the distortion of the near-end speech can be controlled by choosing appropriately the post-filter length