Cepstral analysis for formants frequencies determination dedicated to speaker identification

In this paper, we present a technique of parameterization of the speech based on the cepstral analysis, for the extraction of the first four formants F1, F2, F3 and F4 with the aim of a biomedical application. Indeed, such analysis, supposed linear, assures the speech signal deconvolution. It allows separating the contribution of the vocal tract, i.e. the formants frequencies, and the one of the vocal cords responsible of the fundamental frequency. The technique applied to some vowels extracted from the TIMIT database, allows identifying the variations interlocutors of the formants frequencies according to the sex and of the region. Variability interlocutor is a major phenomenon in speech recognition because a speaker remains recognizable by the timbre of his voice in spite of a variation which can sometimes be significant. Results so obtained allow noticing the variability of the formants frequencies of a vowel pronounced by various speakers. So, several scenarios were tested to know: 1) a vowel pronounced by four men and four women who lived in the same region, 2) a vowel pronounced by four women of the same region, and 3) a vowel pronounced by eight men who lived in different regions.