What this means for learners
TEKE and Yao share 19 sounds — roughly 39% of Yao's inventory overlaps with TEKE. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 30 sounds found only in Yao represent the greatest pronunciation challenge for TEKE 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, TEKE has 9 sounds not used in Yao. Native Yao speakers learning TEKE 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.