What this means for learners
ORMURI and Javanese share 14 sounds — roughly 42% of Javanese's inventory overlaps with ORMURI. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 19 sounds found only in Javanese represent the greatest pronunciation challenge for ORMURI 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, ORMURI has 17 sounds not used in Javanese. Native Javanese speakers learning ORMURI 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.