Sphinx-4 is a part of CMUSphinx Speech Recognition Toolkit. It's a flexible large and small vocabulary speech decoder written in Java and licensed under BSD license.
This tag is about Sphinx-4, a speech recognition decoder. Speech recognition is fastly growing domain and it's quite complex by its nature. The development of the speech recognition application requires understanding of the speech recognition specifics - a probabilistic nature of the results, the need for throughout testing, the specifics of the voice user interface design, the accuracy/speed balance.
The main concept you need to be aware about are acoustic model used to capture the sounds of the language, the language model used to capture the vocabulary and the dictionary which maps from words to sounds. The use of Sphinx-4 in your application is often straightforward but you need to be more careful than usually to get everything in place.
To learn more about CMUSphinx and Sphinx-4 visit CMUSphinx page
https://cmusphinx.github.io/wiki/
Read the tutorial