search algorithm 9 the acoustic model is for example a so called u201c hidden markov u201d model or hmm the language model implemented in the present exemplary embodiment is based on a grammar described with the aid of syntax rules of the backus naur form the language model is used to submit hypotheses to the search algorithm the latter which is the recognition engine proper is as regards the present example a search algorithm based on a viterbi type algorithm and referred to as u201c n best u201d the n best type algorithm determines at each step of the analysis of a sentence the n most probable sequences of words at the end of the sentence the most probable solution is chosen from among the n candidates the concepts in the above paragraph are in themselves well known to the person skilled in the art but information relating in particular to the n best algorithm is given in the work u201c statistical methods for speech recognition u201d by f jelinek mit press 1999 isbn 0 262 10066 5 pp 79 84 other algorithms may also be implemented in particular other algorithms of the u201c beam search u201d type of which the u201c n best u201d algorithm is one example the acoustic phonetic decoder and the linguistic decoder can be embodied by way of appropriate software executed by a microprocessor having access to a memory containing the algorithm of the recognition engine and the acoustic and language models the invention also relates to the language model as well as to its use by the recognition engine the following four syntactic rules are customarily used.