Using Voice Recognition Software or High End OCR Software for Captchas?

I'm looking into different ways to break captchas beyond the captcha services, something I think may have potential is using a high end voice recognition software, I think Nuance Dragon Naturally speaking is the best for this to recognize the voice captchas.

Also, I am going to try using Nuance's OmniPage for some captcha conversion (although I know it won't work for some)...

Just wondering if anyone has tried either of these approaches with these specific softwares