Amazon Polly is an Amazon AI service that uses advanced deep learning technologies to turns text into lifelike speech. Polly includes 47 lifelike voices spread across 24 languages, so you can select the ideal voice and build speech-enabled applications that work in many different countries.
Tarpal Amazon Polly creates great audio outcome. A good number of very natural sounding voices is available for free. The cloud based service is fast and free for the first year and the first 100 000 characters. The files can be used for commercial purposes. Unless one can and is willing to afford the high end commercial subscriptions of NaturalReader Amazon Polly can be an alternative for the non-commercial output basic versions of NaturalReader.