Two novel algorithms for variable frame analysis and word matching for connected word recognition

In this paper we describe two novel algorithms for variable frame analysis and word matching to be used in connected word recognition. The main characteristic of the algorithm for variable frame rate coding is that of smoothing out the non significant spectral fluctuations in speech. To take the different frame durations into proper account, the standard DP-matching algorithm was modified. The proposed modifications serve the purpose of favouring the alignment of similar phonetic events (similar also according to duration) and of emphasizing to the right extent the importance of transient sounds. Experiments on speaker-trained connected digit recognition have displayed higher correct recognition scores than the standard recognizer (10 msec. frame rate), even with a computational load reduced to about 1/10 of the original.