You have to use a decent acoustic model - not the one in the demo.  If you do I think it works &#x27;pretty well&#x27; as a proof of concept.  That said I&#x27;m not recommending Sphinx as a recognition framework, it is way behind the times in 2016, but this is the only &#x27;in the wild&#x27; demo of this I&#x27;ve seen on the web, so I felt it was worth mentioning.