text to speech on BlackBerry

How could I make text to speech on a BlackBerry? 开发者_StackOverflow中文版There are so many applications on BlackBerry that do this. How do those guys work when it is not supported by BlackBerry?

I don't know what applications you are talking about, but there are two options that don't require text to speech on the BlackBerry:

1) if the set of spoken words is small, pre-record the speach for playback at the appropriate time. My Garmin Street Pilot does this;

2) connect to an on-line server, upload the text and download the synthsized speech. This is how all the SMS and email readers I have looked at work.