Comparative analysis and synthesis of formant trajectories of british and broad australian accents

Abstract

Abstract The differences between the formant trajectories of British and broad Australian English accents are analysed and used for accent conversion. An improved formant model based on linear prediction (LP) feature analysis and a 2-D hidden Markov model (HMM) of formants is employed for estimation of the formant trajectories of vowels and diphthongs. Comparative analysis of the formant values, the formant trajectories and the formant target points of British and broad Australian accents are presented. A method for ranking the contribution of formants to accent identity is proposed whereby formants are ranked according to the normalised distances between formants across accents. The first two formants are considered more sensitive to accents than other formants. Finally a set of experiments on accent conversion is presented to transform the broad Australian accent of a speaker to British Received Pronunciation (RP) accent by formant mapping and prosody modification. Perceptual evaluations of accent conversion results illustrate that besides prosodic correlates such as pitch and duration, formants also play an important role in conveying accents.