Cepstral and linear prediction techniques for improving intelligibility and audibility of impaired speech

Human speech becomes impaired i.e., unintelligible due to a variety of reasons that can be either neurological or anatomical. The objective of the research was to improve the intelligibility and audibility of the impaired speech that resulted from a disabled human speech mechanism with impairment in the acoustic system-the supra-laryngeal vocal tract. For this purpose three methods are presented in this paper. Method 1 was to develop an inverse model of the speech degradation using the Cepstral technique. Method 2 was to replace the degraded vocal tract response by a normal vocal tract response using the Cepstral technique. Method 3 was to replace the degraded vocal tract response by a normal vocal tract response using the Linear Prediction technique.