The document discusses speech emotion recognition using deep neural networks. It first provides an overview of SER and the challenges in the field. It then reviews 20 research papers on the topic, finding that most use deep neural network techniques like CNNs and DNNs for model building. The papers evaluated various datasets and algorithms, with accuracy ranging from 84% to 90%. Overall limitations identified included the need for more data, handling of multiple simultaneous emotions, and improving cross-corpus performance. The literature review contributes to knowledge in using machine learning for SER.