Abstract: This study presents the cepstral and trispectral analysis of a speech signal produced by a normal men, men with defective audition (deaf, deep deaf) and others affected by tracheotomy. The trispectral analysis based on parametric method (Autoregressive AR) using the fourth order cumulant, these analyses are used to detect and compare the pitches and the formants of corresponding voiced sounds (vowel a, i and u). The first results appear promising, since it seems, after several experiments there is no deformation of the spectrum as one could have supposed at the beginning, however these pathologies influenced the two characteristics: The defective audition influences to the formants contrary to the tracheotomy which influences the fundamental frequency (pitch).