The Tanzanian Rift region is the only part of Africa that brings together the four major families of African languages

From Unlocking the Secrets of Click Languages by Laure Cailloce.

When I think of language heterogeneity, I always think of Papua Guinea first (850 languages spoken). But multiplicity of languages is not the sole measure of language heterogeniety as Cailloce points out.

The Tanzanian Rift region has long been a source of fascination for linguists. “It’s the only part of Africa that brings together the four major families of African languages,” explains Didier Demolin, a researcher in experimental phonetics and director of France’s Institute of Linguistics, General and Applied Phonetics (ILPGA) in Paris. “They include the Nilo-Saharan languages like Maasai, the Niger-Congo group like the Bantu languages, Afro-Asian tongues like Iraqw, which we are studying, and the Khoisan family, which is mainly found further south but is present in Tanzania through Hadza, with some one thousand speakers.” Iraqw and Hadza are two complex-consonant languages of the Tanzanian Rift that are of particular interest to specialists for their incredible richness. “Hadza is part of the Khoisan group, which can have as many as 130 phonemes, compared with an average of 30 for the world’s other languages,” Demolin notes. “By themselves they represent a good half of the phonatory capacity of humankind – in other words half of all the phonemes that our vocal tracts and articulators are physiologically capable of producing!” Hadza uses 65 different consonants, including a dozen clicks, short percussive sounds produced by a reduction of air pressure in the vocal tract. Iraqw is characterised by “ejective” consonants, veritable blasts of sound that are especially intriguing to phoneticians.