Voice based widget

I want to create a voice based button in a calculator built using tkinter gui, my idea is like if I say press 1 to pc the 1 button to be pressed , my doubt is can I build something like this, secondly how to proceed? I have already built a calculator using tkinter only left out part is to make buttons voice based

Buttons have an .invoke method that calls the callback associated with the button. The hard part is speech recognition on particular systems. I know nothing about that but would look on pypi.python.org and stackoverflow if no one answers here.

Ok tq for your response