Create MP3 which includes different voice ids/languages

Would it be an option in your use case to just generate multiple MP3 files and then edit them together using an audio editing application? That would avoid you having to do any complex programming.

If manual editing isn't practical for your use case, please describe more about how you plan to use the audio, and let us know what programming language you plan to use. I'm not aware of any existing examples (although perhaps others are?), but if you share those details someone may be able to provide some specific guidance.

Thanks for posting back. In theory it would be possible to edit individual mp3s but it wouldn't work because of quantity.

It's for teaching languages. I just want to be able to enter a list of sentences which alternate between the English and the Foreign language equivalent, then create the mp3. I think Google can change voices but they haven't got an easy to use console like aws.