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PART|I Signal Processing, Modelling and Related Mathematical Tools
3.2 SPEECH RECOGNITION
Statistical modelling paradigms, including HMMs and their exten-
sions, are key approaches to ASR. Using proper assumptions, these
technologies provide a mean to factorise the different layers of
the spoken language structure. Several major components hence
appear. First, the speech signal is analysed using feature extraction
algorithms. The acoustic model is then used to represent the know-
ledge necessary to recognise individual sounds involved in speech
(phonemes or phonemes in context). Words can hence be built as
sequences of those individual sounds. This ...