What this means for learners
Cheremis and Kharia share 15 sounds — roughly 32% of Kharia's inventory overlaps with Cheremis. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 32 sounds found only in Kharia represent the greatest pronunciation challenge for Cheremis 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, Cheremis has 19 sounds not used in Kharia. Native Kharia speakers learning Cheremis 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.