6. The method of claim 4 , further comprising using a mathematical equation β r = α r f r to determine an average frame likelihood score of a speech audio file, wherein β r is the average frame likelihood score, α r is the total likelihood score of the speech audio file, and f r is a number of feature frames of the speech audio file.
4. The method of claim 1 , wherein the performing the forced Viterbi alignment further comprises: obtaining a total likelihood score α r for each of the plurality of speech audio files.