Only in Tewa 39
What this means for learners
Tewa and Yao share 18 sounds — roughly 32% of Yao's inventory overlaps with Tewa. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 31 sounds found only in Yao represent the greatest pronunciation challenge for Tewa 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, Tewa has 39 sounds not used in Yao. Native Yao speakers learning Tewa 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.