Lua is spoken along the middle reaches of the
Chari river, Chad. Prenasalized stops occur initially in a
few words but medially could be allophones of voiced stops
after nasalized vowels. Implosives are realized as ? +
nasal before nasalized vowels, but oral and nasalized
vowels contrast after plosives. Boyeldieu (1985)
recognizes complex vowels /wa, ja/ - these are interpreted
as vowel sequences /ua,ia/. All vowels except 'barred i'
appear long and short.

Boyeldieu, P. 1985. La Langue Lua ("Niellim") Groupe Boua
- Moyen-Chari, Tchad. For the: Societe d'Etudes
Linguistiques et Anthropologiques de France, Cambridge
University Press, Cambridge.