19. The apparatus of claim 18 , wherein the external word embedding neural network language model generates input features from the plurality of previous words based on a concatenation of the external embedding matrix to the history word embedding matrix and provides the input features to a hidden layer of the external word embedding neural network language model.
19. The apparatus of claim 18 , wherein the external word embedding neural network language model generates input features from the plurality of previous words based on a concatenation of the external embedding matrix to the history word embedding matrix and provides the input features to a hidden layer of the external word embedding neural network language model. 20. The apparatus of claim 19 , wherein a hidden layer of the external word embedding neural network language model applies a hidden layer weight matrix to the input features.