I wonder if such sort of experiment was already done. Would such stimuli produce never before felt qualia on such people's minds, or would it result in something else? One thing I've read once is that the blind apparently have part of the brain areas used for visual processing used instead for vocabulary, even though I'm not sure how exactly this "content" was figured out, perhaps it was just an unwarranted assumption from the blind's larger vocabulary, which perhaps could be still stored in more conventional places.
I don't have the answer to your exact question. I would assume some form of hallucinations based on the current neuronal maps you already have, somewhat like dreaming, though that's simply a layman hypothesis, and isn't backed in any form. Though, for the latter phenomenon for the blind folk that you describe, there is a process such as neural plasticity which might explain why a blind man would have a section of his brain rewired for more necessary tasks such as vocabulary. A similar process occurs when you lose a limb. Where sections of your sensory cortex becomes rewired by its' neighboring sections, for instance the neighboring section for the arm area would be the face, which does results in the sensation that your lost limb is being touched, by touching your face. So for the blind man, it really depends on what the remainder of the cortex was being wired for. Just some thought, I have no answers.