In Chapter 8 of Lilienfeld's book of Psychology: From Inquiry to Understanding, there are categories of special cases of language learning described from sign language to bilingualism. In reading about these less common ways of learning a language, I thought I'd look further into one of the perhaps greatest "miracles" in language learning; the case of the deaf and blind Helen Keller.
Around the time that young Helen turned 2 years old, she was stricken severely with a disease that left her both blind and deaf. At the age of 7 is when assistant Anne Sullivan came into aid and began teaching Helen everyday objects by complex combinations of taps to Helen's palm. After some time of teaching a huge breakthrough came about when Sullivan kept pouring water over Helen's hand and she eventually made out the sound of the word water with her voice. This was an exceptional feat considering her lack of vocal language her entire life. She also learned spoken language through the feelings of vibrations of those engaging in conversation. Here's an interesting interview with Anne Sullivan demonstrating this method of sensory teaching.
Following her education with Sullivan, she continued in her success in life and became very skilled at using Braille and sign language as well, giving her even more ways to communicate with others around her. She ended up earning a bachelor's degree and writing many novels as well.
Even after reading multiple articles in support of this "miracle", there are quite a few skeptics of the legitimacy of this case. Some claim that the amount of knowledge Helen gained before her deaf and blindness could be a huge factor in the way she relearned the world around her. Without measuring this at the time, it's uncertain to know if the way in which her particular brain adapted to this would be the same in any other case.
Even so, it has been scientifically proven that with the permanent damage of some of our senses, our other senses become stronger and more attentive in order to make up for this loss. This is where there is a thin line drawn, are the conditions that our brains adapt to to make up for one lost sense still possible when another is taken out as well, especially at such a young age were no legitimate verbal language has been built yet? Through the case of Helen Keller we can see there are extraordinary possibilities.