Ursonography was a project from back in 2005 that mixed dynamic typography generated on the fly with a nonsense poem called Ursonate by Kurt Schwitters. The project was pioneeered by Jaap Blonk, ( the performer ) and Golan Levin, ( the software developer ).

To quote:

With the help of computer-based speech recognition and score-following technologies, projected subtitles are tightly locked to the timing and timbre of Blonk's voice...