We describe a neural network-based system for text-to-speech (TTS) synthesis that is able to generate speech audio in the voice of many different speakers, including those unseen during training. Our system consists of three independently trained components: (1) a speaker encoder network, trained on a speaker verification task using an independent dataset of noisy speech from thousands of speakers without transcripts, to generate a fixed-dimensional embedding vector from seconds of reference speech from a target speaker; (2) a sequence-to-sequence synthesis network based on Tacotron 2, which generates a mel spectrogram from text, conditioned on the speaker embedding; (3) an auto-regressive WaveNet-based vocoder that converts the mel spectrogram into a sequence of time domain waveform samples. We demonstrate that the proposed model is able to transfer the knowledge of speaker variability learned by the discriminatively-trained speaker encoder to the new task, and is able to synthesize natural speech from speakers that were not seen during training. We quantify the importance of training the speaker encoder on a large and diverse speaker set in order to obtain the best generalization performance. Finally, we show that randomly sampled speaker embeddings can be used to synthesize speech in the voice of novel speakers dissimilar from those used in training, indicating that the model has learned a high quality speaker representation.
Moore's law has driven silicon chip circuitry to the point where we are surrounded by devices equipped with microprocessors. The devices are frequently wonderful; communicating with them – not so much. Pressing buttons on smart devices or keyboards is often clumsy and never the method of choice when effective voice communication is possible. The keyword in the previous sentence is "effective". Technology has advanced to the point where we are in the early stages of being able to communicate with our devices using voice recognition.
PayPal may be looking into voice recognition to enable more digital commerce use cases in the near future, if a new post-MWC blog post offers any hints. Looking back on last week's event -- for which we featured extensive firsthand coverage -- PayPal Head of Global Initiatives Anuj Nayar notes two dominant trends. One is the Internet of Things, including new connected car technologies like PayPal's new car commerce feature with Shell and Jaguar (and Apple). The other, as Nayar puts it, is "conversational commerce." Looking at emerging digital commerce opportunities in areas like virtual reality, connected appliances, and even drones, Nayar asserts that it "won't be convenient or realistic to pull out a credit card or punch in your information in any of these scenarios".
Since Apple developed Siri there have been great strides made in the science of voice recognition. Will we soon be throwing away our mice and keyboards and simply talking to our computers? Or will the problems I have with Alexa continue to haunt voice recognition? My wife and I are like all married couples at breakfast. We do not speak to each other.