What this means for learners
AKAWAIO and Sundanese share 12 sounds — roughly 46% of Sundanese's inventory overlaps with AKAWAIO. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 14 sounds found only in Sundanese represent the greatest pronunciation challenge for AKAWAIO 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, AKAWAIO has 11 sounds not used in Sundanese. Native Sundanese speakers learning AKAWAIO 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.