What this means for learners
Aghem and Nupe share 28 sounds — roughly 57% of Nupe's inventory overlaps with Aghem. 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 Nupe represent the greatest pronunciation challenge for Aghem 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, Aghem has 21 sounds not used in Nupe. Native Nupe speakers learning Aghem 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.