Fuse Deep Neural Network And Gaussian Mixture Model Systems

In this chapter, we introduce techniques that fuse deep neural networks (DNNs) and Gaussian mixture models (GMMs). We first describe the Tandem and bottleneck approach in which DNNs are used as feature extractors. The hidden layers, which are better representation than the raw input feature, are used as features in the GMM systems. We then introduce techniques that fuse the recognition results and frame-level scores of the DNN-HMM hybrid system with that of the GMM-HMM system.