5. A method of speech recognition using an apparatus having a search controller processor operating in dependence upon a program stored in a program memory, and a plurality of lexical tree processors operating in parallel to perform a speech recognition search process, said lexical tree processors performing tasks initiated at the direction of the search controller, the method comprising the steps of: (i) performing initial estimates of scores for a speech parameter evaluated against a first set of lexical trees by one or more of the lexical tree processors directed by the search controller; (ii) performing a pruning operation using the initial estimates of scores by the search controller; and (iii) performing a complete evaluation of scores evaluated against a second set of lexical trees by the one or more of the lexical tree processors directed by the search controller; wherein the first set of lexical trees is substantially broader than the second set of lexical trees; and wherein the initial estimates of scores is performed substantially faster than the complete evaluation of scores.
5. A method of speech recognition using an apparatus having a search controller processor operating in dependence upon a program stored in a program memory, and a plurality of lexical tree processors operating in parallel to perform a speech recognition search process, said lexical tree processors performing tasks initiated at the direction of the search controller, the method comprising the steps of: (i) performing initial estimates of scores for a speech parameter evaluated against a first set of lexical trees by one or more of the lexical tree processors directed by the search controller; (ii) performing a pruning operation using the initial estimates of scores by the search controller; and (iii) performing a complete evaluation of scores evaluated against a second set of lexical trees by the one or more of the lexical tree processors directed by the search controller; wherein the first set of lexical trees is substantially broader than the second set of lexical trees; and wherein the initial estimates of scores is performed substantially faster than the complete evaluation of scores. 6. A method according to claim 5 , wherein the speech parameter is a feature vector.