A neural network-based system can generate speech audio in the voice of many different speakers, including those unseen during training, after listening to only a few seconds of reference speech. The system consists of three independently trained components: a speaker encoder network, a sequence-to-sequence synthesis network, and an auto-regressive WaveNet-based vocoder. This technology has the potential to be used for various applications, including text-to-speech synthesis and voice cloning. The system's ability to generate natural speech from speakers that were not seen during training is a significant achievement.