See, Hear, Explore: curiosity via audio-visual association

To compute audio features, we take an audio clip spanning 4 time steps (th of a second for these 60 frame per second environments) and apply a Fast Fourier Transform (FFT). The FFT output is downsampled using max pooling to a 512-dimensional feature vector, which is used as input to the discriminator along with a 512-dimensional visual feature vector.