AUTOMATIC EVALUATION OF SPOKEN ENGLISH FLUENCY

This paper presents a method to automatically quantify the spoken English fluency skills of speakers. The focus of this work is to au-tomatically compute a numeric score of spoken fluency that is cor-related with the numerical score the human assessors would assign. The proposed method combines several novel prosodic and lexical features to compute the fluency score. It is shown that the prosodic and the lexical features provide complementary information for flu-ency evaluation. Extensive evaluation on human-labeled utterances shows that the proposed technique exhibits similar trends in perfor-mance and confusions as shown by human assessors. The proposed technique leads to 84.2 % classification accuracy when the two ex-treme classes of fluency are considered. Index Terms — fluency evaluation, language learning, prosodic features, lexical feature