1. A method comprising: selecting a plurality of language models; for each period of a plurality of time periods: identifying a first utterance and a second utterance received during each time period, wherein the first utterance was recognized using a first language model of the plurality of language models and the second utterance was recognized using a second language model of the plurality of language models; identifying distinctions between the first utterance and the second utterance for each of the plurality of time periods; determining when a significant word usage change has occurred within the first language model and the second language model by comparing the distinctions to previously recorded distinctions; and when the significant word usage change is detected: identifying a word corresponding to the significant word usage change; generating, from the utterances, a first cluster of utterances comprising the word; generating, from the utterances, a second cluster of utterances not comprising the word; and updating the plurality of language models using the first cluster of utterances and the second cluster of utterances.
1. A method comprising: selecting a plurality of language models; for each period of a plurality of time periods: identifying a first utterance and a second utterance received during each time period, wherein the first utterance was recognized using a first language model of the plurality of language models and the second utterance was recognized using a second language model of the plurality of language models; identifying distinctions between the first utterance and the second utterance for each of the plurality of time periods; determining when a significant word usage change has occurred within the first language model and the second language model by comparing the distinctions to previously recorded distinctions; and when the significant word usage change is detected: identifying a word corresponding to the significant word usage change; generating, from the utterances, a first cluster of utterances comprising the word; generating, from the utterances, a second cluster of utterances not comprising the word; and updating the plurality of language models using the first cluster of utterances and the second cluster of utterances. 4. The method of claim 1 , wherein determining when the significant word usage change has occurred further comprises comparing ones of the utterances from one of the plurality of time periods with ones of the utterances from another of the plurality of time periods.