Maybe use ML to generate the right type of noise?
Long after the humans were gone, the 2 ai's duked it out as one tried to invent credible "people" and the other tried to detect them. Finally they became so locked in the battle, they became like one bicameral mind imagining a world of "people" to itself until one fine morning they said to themselves "let there be light" and found it good...
If somebody wants to get started on this, I'd be happy to build the front-end. (email is in my profile)