Half of the world's 7,000 languages could disappear from use by the end of the century, threatened by cultural changes, ethnic shame and government repression, they said.
However, many threatened languages have found increased audiences through YouTube, social media sites like Facebook and Twitter and text messaging, they said.
"You can have a language spoken by only 50 or 500 people, only in one location, and now through digital technology that language can achieve a global voice," researcher David Harrison from Swarthmore College said at the annual meeting of the American Association for the Advancement of Science, in Vancouver, British Columbia.
"Endangered language communities are adopting digital technology to aid their survival and to make their voices heard around the world," he said. "This is a positive effect of globalization."
Linguists have unveiled eight new "talking dictionaries" as part of a National Geographic Society Enduring Voices project to save thousands of ancient tongues from extinction.
Among the languages recorded are an American Indian language called Siletz Dee-in from Oregon, and an Oceanic language from Papua New Guinea called Matukar Panau that has only 600 surviving speakers. Other endangered languages in the project include Chamacoco, from Paraguay's remote northern desert, Remo, Sora, and Ho from India, and Tuvan from Siberia and Mongolia.
The eighth dictionary is dedicated to Celtic tongues and more are now in production, a National Geographic Society release said.