Nice wrapper. That said, the standard Web Speech API really is pretty straightforward if you want to play with the raw API.

I'm surprised Firefox doesn't support any part of the API. Granted, it's a Google-pushed spec, but they seem to have been working together on the now-defunct Text-to-Speech API. Plus, the speech synthesis aspect is merely handled by the OS (unlike the recognition aspect which is probably handled by Google for most users). I don't really follow web spec stuff though, so I'm pretty out of the loop.