What this means for learners
Mapudungun and Lingala share 17 sounds — roughly 61% of Lingala'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 5 sounds found only in Lingala 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 11 sounds not used in Lingala. Native Lingala 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.