Vowels occur both long and short. Long mid
vowels occur but are analyzed as vowel-glide-vowel,
/aji/ -> [e:] etc. Stops are "occasionally voiced
medially". Initially alveolar stops and nasals don't
occur, and dental and palatal stops and nasals (the
"laminals") are largely predictable variants (dental
initially, medially mostly predictable from vowel
environment).

Donaldson, T. 1980. Ngiyambaa, The Language of the
Wangaaybuwan. Cambridge University Press, Cambridge,
London, New York.