A Study of Phone Recognizer Combination for Higher Accuracy in Timit Phone Recognition

Generally, phone recognition system contains only a single phone recognizer. The phone set and speech representation for a recognizer are optimized for a particular task. This paper studies the effect of phone sets and speech representations for TIMIT phone recognition task. Two phone sets (TIMIT original phone set and 39 classical phone set) and two speech representations (MFCC-based and PLP-based) are tested. The phone recognizers for each phone set and speech representation are experimented and analyzed on both TIMIT training and testing sets. The results show that the 39 classical phone set with PLP speech representation phone recognizer yields highest phone accuracy. However, this best phone set works well only on a particular phone subset while the other recognizers work better on the other subsets. Therefore, the combination of several phone recognizers indicates higher phone accuracy than any single phone recognizer.