Wow, it is so nice to hear a calm, easy voice speaking rather than Siris stern firm voice. I agree that Apple should license these voices as Siri alternatives. Under iOS 6, I get a British Female voice on my iPhone and an American Female voice on my iPad as defaults (probably because I set my iPhone to British English so the Siri voice would be the British Butler rather than the obnoxious female voice).
Ironically, I cant seem to be able to change the voices for this app to anything other than the default. The voice settings are hidden way away under the Settings app (rather than selectable within the app which would be way easier). There are lots of voice options listed, so I hope this bug will be fixed soon.
Ive had no problem copying and pasting whole news articles into the app for reading. Closing all other open apps and relaunching this one seems to assure there is enough memory available to run correctly.
Thorough Review about Talking Text with Real Human Voice