Prepenultimate Devoicing (Cheyenne)

Rule V[-high] > [-voice] / C __ C[-voice,+cont] C0 V C0 V
Abbreviation PPD
Type Synchronic phonological
Notes

Applies iteratively.

Condition: does not apply if preceding consonant is [h].

"A vowel (which does not have high pitch) is devoiced is followed by a voiceless fricative and not preceded by h."

Sources