Languages are vanishing from the Earth. There are 6192 different languages but half could become extinct by the end of this century. But two linguists are determined to capture the languages before they disappear forever. DAVID HARRISON, professor of linguistics at Swarthmore College, and GREGORY ANDERSON, director of the Living Tongues Institute for Endangered Languages, scour the earth, recording languages that often only have a few speakers still living. In fact, recently they uncovered a hidden language in India called Koro that few people knew about. This hour, Marty listens to recordings of endangered languages and talks with Harrison and Anderson about how to save them.