http://musharraf.ml/mushytalkback/
For those wondering, I'm just passing along the info about it here, for those who aren't on the Eyes-Free list.
It is based on Talkback 4.3.1, which is now Open Source on GitHub:
https://github.com/google/talkback/
, and the goal was to make the sounds less midi-like, thus why it was born.
Please direct your comments to the maintainer on Twitter or via email, which can be found on the Mushy Talkback page in question, for sharing feedback/suggestions.
Enjoy!