I recently came through this interesting design question, which has been stuck in my head since then.
Now, putting myself in such a persons shoes (though its weird and tough to think like that), without vision and hearing sense, i cant think of any substantial measure to do simple stuff, like how to decide where to push a coin to get a coke, or where to swipe my hand to book a ticket, or maybe something simple like that.
What i can think of is maybe, machine is designed in some touch-oriented fashion. Like we can get some knowledge of where to proceed, by touching at some random position.
I may sound too stupid, but that's it, nothing innovative is striking me right now.
I need a interview oriented answer. Any suggestions?