I Introduction
Accent is one of the most fascinating aspects of speech acoustics. An accent is a distinctive characteristic manner of pronunciation, usually associated with a community of people with a common regional or social/cultural background. Accents are dynamic processes that evolve over time influenced by large immigrations and social and cultural trends. J.C. Wells [1] provides an excellent introduction to the linguistic structures of accents of English language. In [2,3] Watson and Harrington describe a comparative analysis of formants of British English, Australian English and New Zealand English and three subclasses of Australian namely: Broad Australian English, General Australian English and Cultivated Australian English.
The paper investigates the distribution of the linguistic structure and acoustic correlates of three major accents of the English language namely British, Australian and American accents. An accent profile is proposed to describe the statistics of the acoustic correlates of each accent and its distinct phonetic transcription. Accent profiles can be used for accent synthesis in TTS and in recognition of accented speech. Accent analysis is based on three large speech databases of American, British and Australian English accents. Speech signals are modelled with hidden Markov models and analysed to obtain phonetic segmentation and labels, formants and pitch marks. From these the statistics of the acoustic correlates of accents namely duration, pitch trajectory, formants and their trajectories, the slopes of initial and final pitch rise or fall and the tone nuclei parameters are estimated. Accent synthesis involves modification of the spectral and temporal correlates of the source accent to those of the target accent and the use of accent transcriptions. Experimental evaluations of the effects of accent on computer speech recognition and on the use of accent profiles for accent synthesis are presented. Perceptual evaluations provide a ranking of accent correlates and demonstrate that accent profiles are capable of synthesising accents.
1.1 Overview of British and American English
1.2 Overview of Australian English