Language is always evolving, and this new form of communicating emerged in the early 2000s. Deaf-blind Americans created a language that uses humans' first language -- touch. No sight or sound needed.
Pro-Tactile American Sign Language is not widely known, but it's changing the way deaf-blind people communicate with each other. Previously they've relied on Braille, fingerspelling, or using an interpreter
Pro-Tactile borrows from ASL, but also uses the perceiver's hands and body to communicate the message. You would use your hands to sign on their arm, or incorporate the perceiver's limb into the sign to make it with you.
Interpreting this new language then depends on context, much like the spoken word. There are even signals that are equivalent to "uh-huhs" or nods, like a confirming tap on the hand to let them know that you're following along and understand.
Humans instinctively communicate through touch -- think of an encouraging pat on the back or a mother soothing a child. Pro-Tactile ASL proves that there's so much more to tell and opens up an incredible way of sharing within the deaf-blind community.