A comparative study of discriminative training using non-uniform criteria for cross-layer acoustic modeling

This work focuses on a comparative study of discriminative training using non-uniform criteria for cross-layer acoustic modeling. Two kinds of discriminative training (DT) frameworks, minimum classification error like (MCE-like) and minimum phone error like (MPE-like) DT frameworks, are augmented to allow the error cost embedding at the phoneme (model) level respectively. To facilitate this comparative study, we implement both augmented DT frameworks under the same umbrella, using the error cost derived from the same cross-layer confusion matrix. Experiments on a large vocabulary task WSJ0 demonstrated the effectiveness of both DT frameworks with the formulated non-uniform error cost embedded. Several preliminary investigations on the effect of the dynamic range of error cost are also presented.