What this means for learners
Central Khmer and Kota share 24 sounds — roughly 52% of Kota's inventory overlaps with Central Khmer. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 17 sounds found only in Kota represent the greatest pronunciation challenge for Central Khmer 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, Central Khmer has 22 sounds not used in Kota. Native Kota speakers learning Central Khmer 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.