I agree, just trying to think of how it would have to work if it was ever to exist.

I would suppose that voice/gesture written code would be stored as text, when reading you could edit via keyboard or your voice/gesture interface. This comes back to languages written for voice - probably if this became feasible a lot of these languages would be compilers from voice to another traditional text target.

But like many people here I have a hard time actually believing this would ever be useful.