Wake Word Detection with Alignment-Free Lattice-Free MMI
Table 2: Effect of sub-segmentation of negative recordings.
['FRR(%)', 'SNIPS (FAH=0.5)', 'Mobvoi (FAH=1.5)']
We first show the effect of sub-segmenting negative recordings on training. We start from the training data with only speed-perturbation applied. Apparently without sub-segmentation the performance is far from satisfactory, indicating the alignments learned with the LF-MMI system is poor. We also inspected the training/validation loss in both cases (not shown here), and found that there is severe overfitting when training without sub-segmentation.