26. A method for knowledge-enhanced speech recognition, comprising: storing one or more expected contexts in a context stack, wherein a knowledge-enhanced speech recognition engine that includes one or more processors accesses the one or more expected contexts in the context stack in response to one or more active grammars in a context description grammar failing to completely match information associated with the natural language utterance; comparing the information associated with the natural language utterance to one or more context specific matchers to determine a most likely context associated with the natural language utterance, wherein the knowledge-enhanced speech recognition engine determines the most likely context from the one or more expected contexts in the context stack; and using one or more grammar expression entries in the context description grammar to generate a command or request associated with the most likely context, wherein the information compared to the one or more context specific matchers includes phonetic information associated with the natural language utterance or text combinations from a transcription associated with the natural language utterance.
26. A method for knowledge-enhanced speech recognition, comprising: storing one or more expected contexts in a context stack, wherein a knowledge-enhanced speech recognition engine that includes one or more processors accesses the one or more expected contexts in the context stack in response to one or more active grammars in a context description grammar failing to completely match information associated with the natural language utterance; comparing the information associated with the natural language utterance to one or more context specific matchers to determine a most likely context associated with the natural language utterance, wherein the knowledge-enhanced speech recognition engine determines the most likely context from the one or more expected contexts in the context stack; and using one or more grammar expression entries in the context description grammar to generate a command or request associated with the most likely context, wherein the information compared to the one or more context specific matchers includes phonetic information associated with the natural language utterance or text combinations from a transcription associated with the natural language utterance. 27. The method of claim 26 further comprising: dynamically constraining a vocabulary of words associated with a virtual dictation grammar to include one or more decoy words for out-of-vocabulary words based on one or more prior utterances that were successfully transcribed by the speech recognition engine.