What this means for learners
Kabiyɛ and Mambila share 33 sounds — roughly 70% of Mambila's inventory overlaps with Kabiyɛ. 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 Mambila represent the greatest pronunciation challenge for Kabiyɛ 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, Kabiyɛ has 14 sounds not used in Mambila. Native Mambila speakers learning Kabiyɛ 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.