I've just written an online chapter (with code) explaining how to implement simple program sonification in Java. It uses a mix of speech synthesis, note generation, and audio clips while tracing a program's execution.
You can find the chapter at my Killer Game Programming in Java website:
http://fivedots.coe.psu.ac.th/~ad/jg/
It's chapter "Java Art Chapter 5. Program Sonification" which is about half way down the page.
Comments are appreciated.
- Andrew