Patent ID: 7260532

Claim:
A speech model generation apparatus for generating hidden Markov models representative of received speech signals, the apparatus comprising: a receiver operable to receive speech signals; a signal processor operable to determine for a speech signal received by said receiver, a sequence of feature vectors, each feature vector comprising one or more values indicative of one or more measurements of a said received speech signal; a clustering unit operable to group feature vectors determined by said signal processor into a number of groups; a selection unit operable to determine for a grouping of feature vectors generated by said clustering unit a matching value comprising a value indicative of the goodness of fit between said feature vectors and a hidden Markov model having states corresponding to each group of feature vectors divided by the difference between the total number of values in said feature vectors and the total number of variables defining density probability functions for said hidden Markov model, wherein said selection unit is operable to select said number of states for a speech model to be generated utilizing the matching values determined for groupings of feature vectors; and a model generator responsive to said selection unit to generate a speech model comprising a hidden Markov model having the number of states selected by said selection unit, each of said states being associated with a probability density function, said probability density function being determined utilizing the feature vectors grouped by said clustering unit.