What this means for learners
Oneida and Kaliai share 13 sounds — roughly 46% of Kaliai's inventory overlaps with Oneida. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 15 sounds found only in Kaliai represent the greatest pronunciation challenge for Oneida 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, Oneida has 9 sounds not used in Kaliai. Native Kaliai speakers learning Oneida 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.