Has anyone any experience of cochlear implants on adults who are
middle aged or older and, even more to the point, are deaf from birth
and have never acquired proper language?

I have a particular case in mind that I'm investigating. The person
concerned is in the second half of his forties and is highly
intelligent. The problem is that he comes from a third world
background and simply didn't have the support to teach him language.

He has some signing and communicates quite well up to a point because
he is so intelligent.

The final decision will be made by professionals. My dilemma is to do
with how much expectation of a positive result we can have.

Keith