Analysis of Vocal Tract Shape Variability based on Formant Frequency Ratio at Various Conditions of Vowels for Indian English Speakers

Abstract

The paper presents the notability of variation of vocal tract shape and formant frequency with its adjacent ratios, for the Indian English speakers for the five vowels of the English language. we have estimated the vocal tract shape of the Indian English speakers. For the estimation we have incorporated Autoregressive Model and the same for the formant frequency. The speech samples are considered with three various utterances namely the consumption of Ice cold water, with time relaxation of five minutes compared with normal recordings of the vowels namely /a/, /e/, /I/, /o/ and /u/. These utterances are recorded for 20 individual iterations. the vocal tract shape estimation and formant frequency estimation are done on the Matlab platform. the vocal tract shape of first vowel /a/ comes to normal shape rapidly with time lapse of five minutes. the vocal tract shape of vowel /e/ shrinks after consumption of ice cold water and slowly attains the normal shape. The vowel /I/ and /or/ vocal tract shape changes linearly for all the conditions considered, whereas the vocal tract shape of /u/ compresses for ice cold water and retains to be same even after a time lapse of five minutes. All the above variations are done by considering the vocal tract length of 17cm and it is modelled according to lossless uniform tube model. these outcomes are used for observation of vocal tract infection among the speech disorder patients, it can be adopted for the user authentication system by considering it as a vocal tract signature.