What this means for learners
Wichita and Zulu share 15 sounds — roughly 35% of Zulu's inventory overlaps with Wichita. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 28 sounds found only in Zulu represent the greatest pronunciation challenge for Wichita speakers. The adult brain tends to map unfamiliar sounds onto the closest native equivalent — a process that produces the characteristic "accent" of a second-language speaker. Learning to hear and produce these sounds as distinct requires focused ear training, not just repetition.
Conversely, Wichita has 14 sounds not used in Zulu. Native Zulu speakers learning Wichita will face the mirror-image challenge with these sounds.
Phoneme inventories from PHOIBLE. Data reflects one documented inventory per language; some variation exists across dialects and sources.