What this means for learners
Sango and Tiv share 31 sounds — roughly 70% of Tiv's inventory overlaps with Sango. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 9 sounds found only in Tiv represent the greatest pronunciation challenge for Sango 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, Sango has 13 sounds not used in Tiv. Native Tiv speakers learning Sango 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.