Dinka phonology

Consonants
There are 20 consonant phonemes:

Vowels
Dinka has a rich vowel system, with at least thirteen phonemically contrastive vowels. The underdots indicate "breathy" vowels, represented in Dinka orthography by diaereses ($\langle\rangle$):

On top of this, there are three phonemically contrastive vowel lengths, a feature found in very few languages.

Voice quality is also a factor, with four different phonetic types present: modal voice, breathy voice, faucalized voice, and harsh voice in its vowels. Of these, only modal and breathy are phonologically contrastive.

Tone
The extensive use of tone and its interaction with morphology is a notable feature of all dialects of Dinka. The Bor dialects all have four tonemes: Low, High, Mid, and Fall. What is more unusual is that in some dialects there is also a low-fall tone, which appears to differ from the fall primarily in the alignment within the syllable of a peak that defines the beginning of a falling contour. In other words, one peaks earlier than the other. This is interesting because it had been theorized that such timing differences were never phonemic.