Nǁng or Nǁŋǃke, which is also known as Nǀu, is the only surviving member of the !Ui branch of the Tuu or Khoisan language family. It was declared extinct in 1973, but in the 1990s the South African San Institute managed to find 25 people who could speak or understand the language. In 2013 there were just five elderly Nǁng speakers left in Northern Cape Province of South Africa: three speakers of the Nǀuu dialect and two of ǁ’Au dialect.
Under apartheid people who spoke Nǁng had to hide their language and identity from others, including their children. They adopted other languages, such as Afrikaans, and their children did not acquire even a passive knowledge of Nǁng.
Nǁng was first documented in the 1920s. Further documentation of the language was made in the 1990s by groups funded by the National Science Foundation of the USA, the Endangered Languages Documentation Programme, and the University of Cologne. A number of spelling systems for the language were developed.
Source: http://www.kalaharipeoples.org/academic/nuu/Segments.html (includes recordings)
Information about the Nǁng/Nǀu language