Neural networks, maximum mutual information training, and maximum likelihood training [speech recognition]

A Gaussian-model classifier trained by maximum mutual information estimation (MMIE) is compared to one trained by maximum-likelihood estimation (MLE) and to an artificial neural network (ANN) on several classification tasks. Similarity of MMIE and ANN results for uniformly distributed data confirm that the ANN is better than the MLE in some cases due to the ANNs use of an error-correcting training algorithm. When the probability model fits the data well, MLE is better than MMIE if the training data are limited, but they are equal if there are enough data. When the model is a poor fit, MMIE is better than MLE. Training dynamics of MMIE and ANN are shown to be similar under certain assumptions. MMIE seems more susceptible to overtraining and computational difficulties than the ANN. Overall, ANN is the most robust of the classifiers