ESpeak

eSpeak is a free and open-source, cross-platform, compact, software speech synthesizer. It uses a formant synthesis method, providing many languages in a relatively small file size. eSpeakNG (Next Generation) is a continuation of the original developer's project with more feedback from native speakers. Because of its small size and many languages, eSpeakNG is included in NVDA open source screen reader for Windows, as well as Android, Ubuntu and other Linux distributions. Its predecessor eSpeak was recommended by Microsoft in 2016 and was used by Google Translate for 27 languages in 2010; 17 of these were subsequently replaced by proprietary voices. The quality of the language voices varies greatly. In eSpeakNG's predecessor eSpeak, the initial versions of some languages were based on information found on Wikipedia. Some languages have had more work or feedback from native speakers than others. Most of the people who have helped to improve the various languages are blind users of text-to-speech.