Vosk provides speech recognition in Unity with standard Vosk libraries as Unity is essentially C#/Mono scripting environment. For now we have a sample project:

https://github.com/alphacep/vosk-unity-asr

We hope to add some more information soon. For details see

https://github.com/alphacep/vosk-api/issues/691

There are multiple external projects which also integrate Vosk into Unity, you can check them too:

https://github.com/Yeti47/Vosk4Unity

https://github.com/Babilinski/vosk-stt-unity