22. An apparatus for performing speech recognition, the apparatus comprising: at least one computer readable storage medium encoded with a plurality of instructions; and at least one processer programmed by at least some of the plurality of instructions to; acquire a speech signal from a user; perform a first recognition pass by applying a first language model to the speech signal, the first language model being constrained in accordance with a structured data source; and generate a subsequent language model based at least in part on results from the first recognition pass.
23. The apparatus of claim 22 , wherein the at least one processer is further programmed to: perform a subsequent recognition pass by applying the subsequent language model; and recognize the speech signal.