What this means for learners
Nupe and Mandingo share 29 sounds — roughly 76% of Mandingo's inventory overlaps with Nupe. 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 Mandingo represent the greatest pronunciation challenge for Nupe 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, Nupe has 9 sounds not used in Mandingo. Native Mandingo speakers learning Nupe 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.