Somebody (Descartes?) famously proclaimed: "I think, therefore I am". I hope this great philosopher pardons me for correcting him and saying: "I communicate, therefore I am". The need to express ourselves and communicate with others is so strong in human beings that it might be taken to be the essence of being human.
The tragedy is that there are a lot of people who are denied of this very basic faculty of self expression because of some problems with their brain/nervous system. Most of them can't speak, move around or do any kind of mechanical manipulations - the maximum they can do is move a little finger or tilt their head. There are organizations (like Vidyasagar in Chennai) who are working hard to bring light into the lives of these people and integrate them into the mainstream. But the obstacles they face are herculean. One major issue is designing low cost communication devices for these people. A few students from IIT Madras are involved in a project to design one such device - read more about it here.