( CNN ) -- The shaka sign -- a person 's thumb and pinkie extended , the rest of the fingers in a fist -- is uniquely Hawaiian , a way to say `` right on , '' `` hang loose '' or simply hello . But it turns out it 's not the only way islanders have used their hands to communicate . A research group at the University of Hawaii at Manoa announced Friday that they had documented -- for the first time -- Hawaii Sign Language , or HSL , which deaf people across the islands ' diverse ethnic groups have used for decades if not longer . While there is written evidence dating back to 1821 indicating such a language existed , beginning in the 1940s it started to get largely phased out in favor of American Sign Language . Quiz : How good is your sign language ? Researchers identified about 40 Hawaiians who still use it -- interviewing 19 of them , plus two adult children , on four islands for their study . But they are all 80 years of age or older , making it imperative to act now in order to preserve it before it 's too late . `` Researchers are committed to a long term study of HSL with the goals of producing ... a dictionary ( and ) archived videotaped data , '' said James Woodward , an Adjunct Professor of Linguistics at the University of Hawaii at Mano . `` It is also hoped that an effort can be made to revitalize HSL , so that it can be taught in high schools and universities in Hawaii . '' Hearing-impaired people have found ways to communicate for generations , all across the world . That might mean tapping into a well-established language , like ASL or International Sign Language , or finding some other way to get a point across . Comic uses sign language . `` If they do n't have access to learning a sign language that 's already in existence , then a community of deaf people will find a way to communicate , '' said Leanne Hinton , a professor emeritus at the University of California at Berkeley . `` Over time , they will find a way to stabilize and have a structure that becomes an actual language . '' That 's what the Hawaii university researchers say happened -- even if few realized that a distinctive sign language existed for decades on the island until now . While the now-prevailing ASL has rubbed off some , Woodward said it 's been relatively minimal among those practicing Hawaii Sign Language . Specifically , at least 80 % of its signs are distinct , while the rest come from ASL -- which he said is enough to characterize it as its own language , rather than a dialect . For example , the Hawaii Sign Language word for father is to wag your finger -- whereas in ASL , it 's an open hand with fingers spread and a thumb to the forehead . Want to say that someone is telling a lie ? Then put an index finger in the middle of your throat . The grammar structure in Hawaii Sign Language also differentiates it from ASL , Woodward noted . `` Sign languages ... evolve in a community of users , and are not signed versions of spoken languages , '' the university said in a press release . `` The full history of HSL is yet to be told . '' NYC sign language star surprised by fame .
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 .