A comparison of dynamic WFST decoding approaches

In this paper we perform a comparison of lookahead composition and on-the-fly hypothesis rescoring using a common decoder. The results on a large vocabulary speech recognition task illustrate the differences in the behaviour of these algorithms in terms of error rate, real time factor, memory usage and internal statistics of the decoder. The evaluations were performed when the decoder was operated at either the state or arc level. The results show the dynamic approaches also work well at the state level even though there is greater dynamic construction cost.