Nice work, ggulati. I had done some roughly similar stuff, but more basic, using same / similar libraries (but you have researched more libs), a while ago:

Recognizing speech (speech-to-text) with the Python speech module

https://code.activestate.com/recipes/579115-recognizing-spee...

and

Python text-to-speech with pyttsx

https://code.activestate.com/recipes/578839-python-text-to-s...

Good stuff. I like this area.