De-reverberation using frequency-domain center clipper

This paper presents the development and analysis of audio de-reverberation algorithms. The modified frequency-sampling filter (FSF) provides an effective filter bank for splitting a signal into equally spaced frequency channels. The center clipper with optimized voice-activity detector and inverse room transfer function (RTF) is employed at each frequency bin. The nonlinear center-clipping operation is analyzed in theory using a sinusoidal signal and Fourier transform. The results show that the clipper generates odd harmonics and may be reduced by a simple low-pass filter. Computer simulations using real speech and measured RTF show that reverberation effects are suppressed successfully with no obvious distortions.