Adding text to speech functionality to iOS app

Question

I'd like to implement such functionality in my app, and AFAIK, the only choice is to use a third-party library, so I've been looking for possible options. I've found that OpenEars seems to be one of the best free and open-source libraries for that purpose, and it works offline, but it only supports English language and I'd want to offer multilanguage text to speech, at least for English, Portuguese, Spanish and French.

I've read that, for multilanguage support, Google TTS performs well, but it only works online... and I'm not sure if a limit of calls exists, does it? Where could I find detailed info about using Google TTS in iOS?

And finally, I've also read a lot of references to Flite or Festival Lite... but it doesn't seem to support multilanguage either. Does somebody know a free, open-source TTS library for iOS that supports several languages and, preferably, works offline?

Just another question. The app I'm working on may have a commercial version and it is intended to be submitted to the Apple Store. Could the use of any TTS third-party library be a problem?

Thanks a lot

Answer 1

iOS 7 has AVSpeechSynthesizer that can do text-to-speech out-of-the-box without the need of any external frameworks.

For more on this, visit this link .

Answer 2

There is two API's which supports these languages:

1. ispeech
2. acapela

But both are online and paid .

OpenEars is a offline text-to-speech and speech-to-text opensource library. But I don't know whether it supports other languages other than English.

Could the use of any TTS third-party library be a problem? Answer: No, there is no problem with this.

Update (on 27 Aug 2013):
OpenEars now supports Spanish as well as English. (Check the below comment from Halle)