What this means for learners
BRAO and Sundanese share 16 sounds — roughly 52% of Sundanese's inventory overlaps with BRAO. 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 Sundanese represent the greatest pronunciation challenge for BRAO 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, BRAO has 15 sounds not used in Sundanese. Native Sundanese speakers learning BRAO 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.