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.
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. 14. 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: identify a first number of predictions of the first word during ASR testing; determine that the first number is below a threshold; and determine the first prior probability, wherein determining the first prior probability further comprises using the group prior probability for the plurality of words as the first prior probability.