Languages around the world have been lost over time, and this loss continues. The reference work Ethnologue lists 245 indigenous languages in the United States, with 65 already extinct and 75 near extinction.
This language loss happened in several ways. A prominent cause came from the federal government’s push to eradicate Native American culture. Children were taken from their homes to boarding schools and forbidden to use their native languages. By the time they came back home, many had forgotten it. As native peoples dispersed into cities and used English, their original languages also fell into misuse. Though there are documents that have recorded many native languages, they cannot document the vocal attributes of the language–often an important part of understanding the language’s meaning. These languages also includes concepts and culture which cannot be replicated in English.
People are making attempts to preserve languages. The Living Tongues Institute for Endangered Languages has partnered with the National Geographic Society to form the Enduring Voices Project to preserve particularly unique, poorly understood, or threatened indigenous languages. The Administration For Native Americans also provides grants to native communities and nonprofits to teach young people to speak native languages.
The Smithsonian Institution’s Bureau of Ethnology collected audio recordings of Native American languages in the 19th century. You can hear digitized snippets of these languages at the Smithsonian’s site, http://siris.si.edu. In the blue box on the right hand side under “Culture & History” click “Native American Language.” In the new page, on the left hand side under “online media” click “sound recordings.”