Analysis by synthesis of acoustic correlates of British, Australian and American accents

This paper presents analysis through synthesis of the acoustic correlates of British, Australian and American accents by transforming the correlates individually across the accents. The acoustic correlates of accents are grouped into three main categories: (a) the spectral features at formants, (b) the pitch intonation pattern and (c) duration. The modeling and transformation methods for each group of voice features are outlined. The spectral features at formants are modeled using two-dimensional (2D) phoneme-dependent HMM. Subband frequency warping is used for spectrum transformation where the subbands are centred on estimates of the formant trajectories. The F0 contour is used for modeling the pitch and intonation patterns of speech. A method based on the time domain pitch synchronous overlap and add algorithm (TD-PSOLA) is used for transformation of pitch intonation and duration pattern. Perceptual tests based on mean opinion score (MOS) are conducted to rank the main features of accents. Formants are regarded as the most important features of accents, followed by intonation pattern and duration.