From the day in 1899 when he was born, James Castle (1899-1977) was completely deaf. Though he went to school when he was young, he apparently never learned how to read, write, or use sign language, though it's disputed whether he was unable to learn language or just refused to use it. He was never taught about art, either, but that didn't stop him from creating it.
Using found materials such as scraps of paper from packaging or mail, and ink made out of soot from the wood-burning stove mixed with water or saliva, he depicted his surroundings with care and clarity. Undoubtedly, Castle's drawings and collages became his main form of communication, showing his sensitivity and acute understanding of the world around him, despite his inability to understand language.
To learn more about James Castle, I highly recommend watching the film James Castle: Portrait of an Artist (Jeffrey Wolf, 2008). The trailer can be viewed at the Foundation for Self-Taught American Artists.