We eat through the same hole we speak out of. Without changing that, there isn't any way to get the lungs to supply the speaking apparatuses with air unless we cross tubes somewhere.
I think you've missed CS's point rather dramatically. His whole suggestion was to change that - we can have one hole for eating, and another for breathing and speaking.
So... two oral cavities? Two tongues? Four sets of teeth?
Why would the air-hole need teeth? Or a tongue, for that matter. It'd need some way of fiddling around with the air flow to make different sounds, but there's all manner of ways of accomplishing that.
I'm not sure what's so stupid about the whole idea.