Infovox iVox

Infovox iVox, a high-quality multilingual Text to Speech application, provides system-wide clear and pleasant voices to OS X for blind and vision impaired users, for individuals who need audible feedback or reading support, for language learning or for people who prefer listening to their computer.
Infovox iVox 4.0 offers 107 voices in 31 languages becoming the voice that enables your computer to speak.

The naturally-sounding voices can be used in any OS X application that is compatible with Apple Speech Manager, such as Apple's VoiceOver, Safari, Adobe's Acrobat Reader, TextEdit and Preview. Infovox iVox is also included in GhostReader, Proloquo, and VisioVoice offerings from AssistiveWare.
Infovox iVox contains two applications: Voice Manager and Pronunciation Editor. Voice Manager provides a dashboard overview of the Infovox iVox voices allowing you to see the status of the voices on your computer, install and remove voices, activate voices and manage user accounts. Pronunciation Editor is utilized for tailoring the way a word is pronounced by an Infovox iVox voice.
Individual Infovox iVox voices can be downloaded for a 30-day demonstration period via the Infovox iVox Voice Manager and are permanently activated using purchased voice credits. Voices can be purchased through the Voice Manager for $14.99 USD /