1. An automated directory assistance system comprising: a) a speech recognition dictionary including a plurality of vocabulary items potentially recognizable on a basis of a spoken utterance by a user of said automated directory assistance system, each vocabulary item being indicative of a locality in which an entity whose telephone number potentially sought by the user may reside; b) extraction unit for extracting from said speech recognition dictionary on the basis of the spoken utterance by the user a plurality of vocabulary items, each of said plurality of vocabulary items being a candidate having a certain probability to correspond to the spoken utterance, said plurality of vocabulary items forming a list of candidates; c) a plurality of a priori data structures, each a priori data structure containing a plurality of probability data elements, the probability data elements being derived at least in part on a basis of call records indicative of prior automated directory assistance transactions; d) a selecting unit for selecting one of said a priori data structures; and e) a weighing unit for weighing candidates in said list on a basis of probability data elements in said one of said a priori data structures.
2. An automated directory assistance system as defined in claim 1, wherein said weighing unit for weighing the candidates establishes for each candidate a compound probability value that is indicative of a likelihood of match of the candidate with the spoken utterance, the compound probability depending in part on a degree of acoustic match between the candidate and the spoken utterance and depending in part on a probability data elements in said one of said a priori data structures.