But use of technologies, even by peoples without written languages, "is a heartening trend," said Harrison. "Language extinction is not an inevitability."
"Using social media, Youtube, text messaging, to expand their voice, expand their presence (is) the flip side of globalization," said Harrison.
"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."
Languages matter, said Harrison, because linguists and other researchers "gain immense insight into human cognition, botany, pharmacology. All disciplines of scientific inquiry are immeasurably enhanced."
Linguist Margaret Noori said languages are a gateway to so-called traditional knowledge. For example, an Ojibwe term for wetlands, translated as "'where the land bleeds,' shows a different way of understanding the science of a place," she told reporters.
Noori said that in North America's Great Lakes region, apps for iPhones, a Facebook page, online lessons and a web site with dictionaries and songs are keeping alive the aboriginal Anishinaabemowin language.
Noori said new estimates show just 5,000 people in North America speak Anishinaabemowin, once the mother tongue of 200 aboriginal nations, known as tribes or bands.
Before laws changed in the US and Canada, the language was almost eradicated by official government policies, including placing aboriginal children in church or state-run residential schools.
Noori, a professor at University of Michigan, Ann Arbor, whose activist aboriginal parents raised her to speak her ancestral language, said the written goal of residential schools was to "kill the Indian to save the man."
She recalled being a child watching police raids of traditional drum circles and religious celebrations during America's turbulent civil rights movements of the 1960s and 1970s, when police cracked down on the political American Indian movement.
Now schools and area universities are using digital technology to promote Anishinaabemowin, with a web site, http://www.umich.edu/~ojibwe/ that includes traditional poems put to music, the informal anthem of the American Indian movement, and a translation into the language of a candy ad shown during the US Superbowl football game and translated lyrics by pop stars.
She said she sees the change in her own household.
"I told my daughter 'you can't have an iPhone unless you text me in the App,'" Noori quipped.
Harrison released eight new "talking" dictionaries of languages at the American Association for the Advancement of Science meeting in Vancouver.
The dictionaries include Matukar Panau, an Oceanic language spoken by just 600 people in Papua New Guinea; Chamacoco, spoken by some 1,200 people in northern Paraguay; the Indian languages Remo, Sora and Ho; and Tuvan, used by nomads in Siberia and Mongolia; and a Celtic-tongue dictionary.
The talking dictionaries are produced by National Geographic's Enduring Voices project and the Living Tongues Institute for Endangered Languages.