The Great African Rift includes several linguistic areas belonging to the four major language families of the continent (Afro-Asiatic, Niger-Kongo, Nilo-Saharan and Khoesan). The linguistic diversity of this area is the result of migrations and contacts, sometimes very ancient, between populations of hunter-gatherers, pastoralists and farmers. The comparison between languages suggests several migratory phases and contacts that have repeatedly modified the linguistic landscape. Some languages like Sandawe and Hadza spoken in Tanzania have similar sounds, clicks, to those of the Khoesan family found in Botswana and Namibia.

The sound systems of the Rift languages have particular sound types, some of which are not common in the world’s languages. The case of non-pulmonic consonants such as ejectives, implosives, and clicks is particularly notable. Hadza and Sandawe have sound systems with clicks, ejectives and prenasals. Iraqw, a South Cushitic language (Afroasiatic family) spoken in the Manyara and Arusha regions of Tanzania has a consonantal system that includes a contrast between modal and labialized consonants, a long series of unvoiced fricative consonants and a series of ejective consonants. Maasai, a Nilotic language, has a complete set of implosives in its phonological system, a complete system of vowels [+/- ATR], and tones. In our project, the focus is on several languages from different linguistic families to explore the phoneme production mechanisms of these languages.