Funnily enough, I also made a C90 port of the same code, and also named it "voc". Here is an oldish version:
http://ultra-premium.com/scratch/voc.zip
I would completely expect yours to be better in all ways (mine was basically a line for line transcription of all the audio and stripping out the UI stuff, where as you actually went to the effort of understanding the thing being ported).