What this means for learners
Ao-Naga and Kabardian share 14 sounds — roughly 22% of Kabardian's inventory overlaps with Ao-Naga. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 49 sounds found only in Kabardian represent the greatest pronunciation challenge for Ao-Naga 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, Ao-Naga has 21 sounds not used in Kabardian. Native Kabardian speakers learning Ao-Naga 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.