Evaluation of an Improved Deviation Measure for Two-Path Echo Cancellation

The two-path algorithm is a well-known approach for overcoming the dead-lock problem in echo cancellation systems. Typically, a fixed foreground filter is producing the echo cancelled output while a continuously updating background filter adapts to the echo-path. When the background filter is considered to perform better than the foreground filter, the coefficients of the background filter are copied into the foreground filter. To determine which filter is better adjusted to the true echo-path, a filter deviation measure can be used. Recently, a method which introduces a delay in the calculation of the filter deviation measure, yielding a more reliable estimate has been proposed. However, a thorough evaluation of the effect of different delay settings has not yet been performed. Thus, in this paper a number of simulations with different delay parameter settings are carried out to show how this parameter affects the overall performance of the filter deviation measure.