While I was an undergraduate at Stanford, I was involved in research with Jonathan Berger and Oded Ben-Tal into the sonification of complex multi-dimensional data using vowel sounds.
I developed instruments in CLM (Common Lisp Music) and STK (The Synthesis Toolkit) to facilitate our research. Vowel sounds were synthesized using subtractive synthesis and formant filters.
(Some documentation of my undergraduate research, not recently updated!)