7. The method of claim 1 , further comprising: specializing the secondary ASR recognizer by using an adaptation grammar of structure and content appropriate to a putative span type, as determined by NLU processing, said adaptation grammar additionally including acoustic prefix words, acoustic suffix words, or both, as transcribed by the primary ASR recognizer to ensure high accuracy secondary ASR recognition in view of coarticulation effects in the processed utterance and potential imprecise determination of span start and end times; and correspondingly expanding said span to include said acoustic prefix words, acoustic suffix words, or both.
11. The method of claim 7 , wherein the proper name entities defining the structure and content of the adaptation grammar used to specialize the secondary ASR recognizer are derived from any of: (a) numbered street addresses associated to a particular locale; (b) roadway intersections associated to a particular locale; (c) landmarks associated to a particular locale; and (d) any combination of the foregoing; and wherein said locale is determined by analysis of the utterance received from the user and supplied as an element of the span type.