Deep learning is one of the various computation methods using artificial neural networks. Neural network with many hidden layers are sometimes called deep neural network. In the narrower sense, neural networks, with unprecedented computational performance similar to human brain, are called deep learning. Examples include Convolution Neural Network, Recurrent Neural Network, Autoencoder, Generative Adversarial Network, and Reinforcement Learning. As time permits, I introduce the concept and how to use it. I also introduce the results of our study on how deep learning is applied to auditory research.