What this means for learners
Asmat and Nyangumata share 7 sounds — roughly 26% of Nyangumata's inventory overlaps with Asmat. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 20 sounds found only in Nyangumata represent the greatest pronunciation challenge for Asmat 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, Asmat has 12 sounds not used in Nyangumata. Native Nyangumata speakers learning Asmat 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.