Records dating to the 1800s pointing to a sign language on the Hawaiian islands . Hearing-impaired people have found ways to communicate for generations , all across the world . Score: 6 A professor says at least 80 % of its signs are distinct from American Sign Language .
Records dating to the 1800s pointing to a sign language on the Hawaiian islands . Score: 6 A professor says at least 80 % of its signs are distinct from American Sign Language .