Software speech synthesizer (text-to-speech)
The eSpeak NG (Next Generation) Text-to-Speech program is a speech
synthesizer that supports 100 languages and accents. It is based
on the eSpeak engine created by Jonathan Duddington. It uses
spectral formant synthesis by default which sounds robotic, but can
be configured to use Klatt formant synthesis or MBROLA to give it a
more natural sound.