What this means for learners
Bhumij and Kota share 36 sounds — roughly 67% of Kota's inventory overlaps with Bhumij. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 5 sounds found only in Kota represent the greatest pronunciation challenge for Bhumij 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, Bhumij has 18 sounds not used in Kota. Native Kota speakers learning Bhumij 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.