This paper investigates performance measures of adaptive echo cancellers for packet-based telephony. It is shown that steady-state echo return loss enhancement (ERLE) does not accurately reflect perceived echo canceller convergence when background noise is present. An upper bound is derived for the maximum perceivable ERLE achievable in practice, and an algorithm is introduced for calculating ERLE that incorporates these masking effects based on a perceptual hearing model. Simulation and informal listening test results show a clear correspondence between the new performance measure and the perceptual upper bound induced by background noise.
James D. Gordy, Rafik A. Goubran