Evaluations of an Echo Suppressor Based on a Frequency-domain Model of Highly Nonlinear Residual Echo

This paper presents evaluations of a nonlinear-echo suppressor based on a frequency-domain model of highly nonlinear residual echo. The residual-echo model, which is based on correlation between spectral amplitudes of residual echo and echo replica, is evaluated by a regression analysis. The results justify the nonlinear-echo suppressor structure. The output signals are subjectively evaluated by mean opinion score (MOS). The score of the nonlinear-echo suppressor is superior to an echo canceller with a linear adaptive filter by 0.8 points on a 5-point scale. In implementation on a DSP system, it is shown that the nonlinear-echo suppressor requires 6.1 to 16.8 MIPS depending on the memory allocation.