What this means for learners
Mapudungun and Bemba share 19 sounds — roughly 68% of Bemba's inventory overlaps with Mapudungun. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 6 sounds found only in Bemba represent the greatest pronunciation challenge for Mapudungun 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, Mapudungun has 9 sounds not used in Bemba. Native Bemba speakers learning Mapudungun 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.