Around seven Tanzanian sign languages were developed independently among deaf students in separate Tanzanian schools for the deaf starting in 1963, though use of several are forbidden by their schools. In 1984, a standardized Tanzanian Sign Language was proposed by the Tanzania Association for the Deaf, using common or similar signs where these exist in the schools which allowed research, but it has not been officially implemented, and there remains little influence between the languages. A dictionary has been produced. Lexically, the variety that developed in the oralist deaf school in Tabora is significantly different from the dictionary, and is under investigation.
The common Swahili term in Tanzania for these languages is lugha ya alama (ya Tanzania), lit. '(Tanzanian) sign language'. The term lugha ya bubu 'mute/dumb language' is also used, but is pejorative and offensive.
^a Sign-language names reflect the region of origin. Natural sign languages are not related to the spoken language used in the same region. For example, French Sign Language originated in France, but is not related to French. Conversely, ASL and BSL both originated in English-speaking countries but are not related to each other; ASL however is related to French Sign Language.
^b Denotes the number (if known) of languages within the family. No further information is given on these languages.^c Italics indicate extinct languages.