Analysis of acoustic correlates of British, Australian and American accents

This paper presents an analysis of the acoustic correlates of the differences of British, Australian and American English accents. The structures of the differences that characterise accents in speech can be divided into two parts: (a) phonetic differences; and (b) acoustic differences. The focus of this paper is on the analysis of acoustic correlates of accents including formants and their trajectories, pitch trajectory, pitch accent, pitch nucleus, duration and speaking rate. The acoustics of accents are modelled and estimated using 2D HMMs of formants and a model of pitch such as the rise/fall/connect (RFC) model. The differences between the accents are discussed. The Australian accent has a lower 1^st formant (F1) but higher 2^nd formant (F2) compared to British and American. The 2^nd formant in speech is considered as the most sensitive to accent identity. British speakers have the largest pitch frequency range and the largest initial pitch rise and final pitch fall rates in utterances. Australian accent exhibits significant elongation of vowels and the lowest speaking rate compared to other two accents. The differences in acoustic correlates across accents are used to morph the accent of a source speaker towards a target accent.