Hynek Hermansky Louis Anthony Cox Jr. Perceptual linear predictive (PLP) analysis-resynthesis technique. 1991 EUROSPEECH http://www.isca-speech.org/archive/eurospeech_1991/e91_0329.html conf/interspeech/1991 db/conf/interspeech/eurospeech1991.html#HermanskyC91