Cheyenne phonology is not exceptionally complex. While there are only three basic vowels, they can be pronounced in three ways: high pitch, low pitch, and voiceless[1]. The high and low pitches are phonemic, while vowel devoicing is governed by environmental rules, making voiceless vowels allophones of the voiced vowels. The digraph ‘ts’ represents assibilated /t/; a phonological rule of Cheyenne is that underlying /t/ becomes assibiliated before an /e/ (t > ts / __e). Therefore, ‘ts’ is not a separate phoneme, but an allophone of /t/.
The standard Cheyenne orthography is neither a pure phonemic system nor a phonetic transcription; it is, in the words of linguist Wayne Leman, a "pronunciation orthography." In other words, it is a practical spelling system designed to facilitate proper pronunciation. Some allophonic variants, such as voiceless vowels, are shown.
Phonology
| bilabial | dental | palatal | velar | glottal | |
| stop | p | t | k | ? | |
| fricative | v | s | S | x | h |
| nasal | m | n |
| front | central | back | |
| non-low | e | o | |
| low | a |
[1] There are also three other variants of the phonemic pitches: the mid, raised-high and hanging-low pitches. These are often not represented in writing, although there are standard diacritics to indicate all of them.