5. A computer-implemented method, the method comprising: receiving audio data corresponding to a first utterance; performing 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 generating output data using the hypothesis.
8. The computer-implemented method of claim 5 , wherein the plurality of words are grouped based on a language frequency.