9. The method of claim 7 , wherein determining the first score comprises determining a score that indicates a perplexity of the first language model; and determining the second score comprises determining a score that indicates a perplexity of the second language model.
7. The method of claim 1 , further comprising: determining a first score based on the output of the first language model; determining a second score based on the output of the second language model; and comparing the first score and the second score, wherein selecting the first class or the multiple second classes is performed based on comparing the first score and the second score.