
56
PART|I Signal Processing, Modelling and Related Mathematical Tools
Stated as such, however, the sequence of spectral parameters pro-
duced by each state of the model will obviously be composed of a
sequence of identical spectral parameters: the mean of the underly-
ing multivariate Gaussian (which by nature maximise the Gaussian
distribution). The main feature of HMM-based synthesis is thus the
use of dynamic features, by inclusion of dynamic coefficients in the
feature vector. This too is typical of HMM-based ASR techniques
but poses a specific problem in HMM-based speech synthesis: how
to find a sequence of (static and dynamic) spectral features which ...