6. The computer-implemented method of claim 4 , further comprising: determining that a particular word or phrase was generated by the expanded speech recognizer that indicates the particular utterance comprises a voice search command.
4. The computer-implemented method of claim 1 , wherein the first transcription was generated using a limited speech recognizer, the limited speech recognizer comprising a speech recognizer that includes a language model that is trained over a limited speech recognition vocabulary that includes one or more terms from a voice command grammar, but that includes fewer than all terms of an expanded grammar; and wherein the second transcription was generated using an expanded speech recognizer, the expanded speech recognizer comprising a speech recognizer that includes a language model that is trained over an expanded speech recognition vocabulary that includes all of the terms of the expanded grammar.