What this means for learners
ROTOKAS and BODO share 7 sounds — roughly 33% of BODO's inventory overlaps with ROTOKAS. 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 BODO represent the greatest pronunciation challenge for ROTOKAS 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, ROTOKAS has 4 sounds not used in BODO. Native BODO speakers learning ROTOKAS 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.