What this means for learners
IVATAN and Bugis share 20 sounds — roughly 80% of Bugis's inventory overlaps with IVATAN. 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 Bugis represent the greatest pronunciation challenge for IVATAN 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, IVATAN has 3 sounds not used in Bugis. Native Bugis speakers learning IVATAN 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.