Sequence Prediction with Neural Segmental Models
Table 4.4: Phone error rates (%) of proposed and baseline systems.
['baseline', 'dev', '1st pass 21.9', '2nd pass 21.0', '3rd pass']
First, if we compare the one-pass baseline with the proposed two-pass system, our system is close to the baseline. Second, we observe a healthy improvement by just adding the bigram language model score to the second-pass baseline. The improvement for our third-pass system is small but brings our final performance to within 0.4% of the baseline second pass. The speedup mostly comes from the fast convergence of the first pass. In terms of training the segmental models alone, we achieve an 18.0-fold speedup. If the time to train the LSTMs is included, then we obtain a 3.4-fold speedup compared to the baseline.