Improved postfiltering technique for block quantisation of speech
H.A. Kaouri, John V McCanny · Electronics Letters · 1987
A modified comb filtering technique is proposed which can be used to reduce framing noise generated when speech signals are transform-coded or vector-quantised. Application of this filter to 9.6 kbit/s speech in a vector transform coder has been found to significantly improve the perceptual quality of the coded speech.