NEW DELHI // India boasts a staggering 1,635 languages, including one spoken by only 31 people.
But this linguistic treasure is vanishing rapidly as Indians turn away from their mother tongues towards more widely used languages, experts say.
Endangered Languages, a project launched last month by Google and the international Alliance for Linguistic Diversity, lists 53 Indian languages under varying levels of threat.
The United Nations Educational, Scientific and Cultural Organization (Unesco) paints an even more dire picture. It lists 197 Indian languages on a scale of "vulnerable" to "extinct."
Up to 42 of these languages are classified as "critically endangered". Among them is Jarawa, spoken by 31 people on an island in the Andamans archipelago, and Tai Rong, spoken by 100 people in Assam.
When a language disappears, more than words and sounds are lost, said Narayan Kumar Choudhary, a linguistics scholar with a doctorate from New Delhi's Jawaharlal Nehru University.
"Each of these languages will have a unique perspective upon the world, a way of looking at the world," Mr Choudhary said. Losing a language, he added, is "like losing a particular body of human knowledge".
Twenty-two languages are used for official administrative purposes in India but there are 1,613 other languages and dialects in use, according to a 2001 census. The SIL Ethnologue, a statistical survey of the world's languages, lists 452 languages in India.
The Central Institute of Indian Languages, a government-funded institution in Mysore, Karnataka, has gathered archives and documents in 118 of India's languages, including 80 tribal languages. Its director, SN Barman, said the state's policy was to encourage multilingual education and a diversity of languages.
"Here, for instance, we're trying to develop materials that can be used to provide education in various mother tongues in India," Mr Barman said. "The fear of endangerment of languages is felt less acutely here, I believe, than in parts of the western world."
Mr Choudhary said many communities were dropping their mother tongues to learn a pan-Indian language such as Hindi, which has 180 million speakers, or to master an international language such as English.
India's opening to the world economy has its benefits, Mr Choudhary acknowledged. "You can't squeeze people into their own communities and keep them there, because then you'd be denying them those benefits of globalisation. The only way out is to document the language before it vanishes. I don't see any other solution."
An Endangered Languages map portrays the scope of the loss. It shows dense clusters of imperiled languages in south-east India, in the tribal belts of Orissa and Central India, in the Andaman Islands in the Bay of Bengal, and in the foothills of the Himalayas.
Languages described as "severely endangered" include Kota, spoken in the Nilgiri Hills of Tamil Nadu; Sentinel and Onge, spoken in the Andamans; and Ashing, Anal and Jad, Sino-Tibetan dialects from the north and east.
One project to document a fast-disappearing language is called Vanishing Voices of the Great Andamanese (Voga), initiated by Jawaharlal Nehru University, London's School of Oriental and African Studies and the Hans Rausing Endangered Language Fund.
Working with the indigenous Andamanese speakers of the Andaman Islands, Voga's scholars collected oral histories, songs, pictures and videos from local participants.
The material was used to compile a Hindi-English-Great Andamanese dictionary of 4,250 words, as well as into ethnographic and cultural studies.
"Often, we'd find that there would be only seven or eight really good speakers of a language," said Bidisha Som, an assistant professor of linguistics at the Indian Institute of Technology in Guwahati, and one of the Voga scholars.
"The children weren't learning Great Andamanese anymore - they were learning Hindi. And the older speakers kept dying out."
In January 2010, when Boa Senior, one of the key participants in the Voga project, passed away, obituaries appeared in media all over the world.
Boa Senior was born in 1925 and was the last surviving person who spoke Bo, one of the Great Andamanese languages. After her death, the language became extinct.
"Though Boa had no one to talk to in her native language, she was often sighted talking to birds … as she maintained that birds were her ancestors and understood her," Voga said in its obituary of Boa Senior. "She was a celebrity overnight but alas when she was alive no one knew of her!"
The speakers of many minor Indian languages, Ms Som said, are running out of reasons to retain their mother tongues.
"They have lost a sense of belonging to the language and culture," she said.
Government policy aside, the effort to preserve a language can only come from within the community, Ms Som said.
"This is why part of our work as linguists is to instil some kind of self-respect within people," she said. "Unless they start taking pride in their language, and believe that it is crucial to preserve it, nothing can be done."