What this means for learners
Luiseno and Kaliai share 18 sounds — roughly 53% of Kaliai's inventory overlaps with Luiseno. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 10 sounds found only in Kaliai represent the greatest pronunciation challenge for Luiseno 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, Luiseno has 16 sounds not used in Kaliai. Native Kaliai speakers learning Luiseno 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.