Fast and free Speech Recognition with Google's Voice API
fennb.com
fennb.com
Unless Google provides an explicit Terms Of Service for this API endpoints allowing its use, you can assume that it exists only to serve Google-owned software (like Chrome).
Just because it exists doesn't mean you can use it.
There's an obvious risk that Google can modify the API and less obvious legal risk of misusing someone else's resources.
Doesn't mean you can't play with it and use it for experiments but you probably shouldn't cross the line of actually using it in any production software.
I wouldn't rely on this for anything I wanted to support, but I don't see that it is incurring a legal risk to work with source code Google themselves have released.
Or is there any kind of open-source project? I guess there probably is not since the training set for modern systems would be terabytes of audio data and probably more proprietary than the algorithms.
I have this on my project list for some home automation ideas, but it is too far down to actually have been given any cycles.
http://msdn.microsoft.com/en-us/library/ms723627(v=vs.85).as...
There's a server version of it with Microsoft Lync I think.
Microsoft also has a cloud service for the same:
http://www.microsoft.com/en-us/Tellme/technology/default.asp...
For me personally I wouldn't be interested in using anything besides the most accurate prediction. However, I would probably make the alternative hypotheses available to choose in case the best prediction is incorrect. In that case I can only assume that the hypotheses are listed in decreasing order of confidences.