It turns out TF7 seems to support some Voiceover operation. I have been experimenting with other software synthesizers, and have learned a few things along the way. I use an external keyboard, and was able to find the MIDI settings. I was able to change voices. I haven’t done much more than that. I’m almost finished beta testing another synthesizer, and after I write a review for a site that addresses Apple hardware and apps for people who are blind, I’ll look further at TF7.
I also wish that they have that one added soon. My son is also blind and taking some other improvisation course to master every stuff he needs, although there are a lot to learn if he also have options for voiceover application that is design to work for blind person. Hope, this is something on progress right now. By the way, this training program at http://smartleesecreative.com/training/ is where my son taking his improv course.