17. The system of claim 13 , wherein the memory further comprises instructions that, when executed by the at least one processor, further cause the system to: determine that a first number of predictions of the first word during ASR testing is equal to zero, indicating that the first word was not predicted during the ASR testing; determine the plurality of words, wherein each of the plurality of words was predicted during the ASR testing more than once; determine the total number of predictions of the plurality of words during ASR testing; determine the total number of correct predictions of the plurality of words during the ASR testing; determine the group prior probability for the plurality of words using the total number of predictions and the total number of correct predictions; and determine the first prior probability, wherein determining the first prior probability further comprises determining the group prior probability for the plurality of words as the first prior probability.
13. A system, comprising: at least one processor; memory including instructions operable to be executed by the at least one processor to cause the system to: receive audio data corresponding to a first utterance; perform first automatic speech recognition (ASR) processing on the audio data using a language model to generate a hypothesis, the hypothesis including a first word, wherein: the language model was trained using a first prior probability for the first word, the first prior probability based on a group prior probability for a plurality of words, the group prior probability based on a total number of predictions of the plurality of words during ASR testing and a total number of correct predictions of the plurality of words during the ASR testing, at least one of the plurality of words is not included in the hypothesis, and performing the first ASR processing on the audio data comprises: identifying the first word, and determining a confidence score for the hypothesis using the language model; and generate output data using the hypothesis.