Only in Dzongkha 40
What this means for learners
Dzongkha and Lahu share 18 sounds — roughly 31% of Lahu's inventory overlaps with Dzongkha. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 28 sounds found only in Lahu represent the greatest pronunciation challenge for Dzongkha 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, Dzongkha has 40 sounds not used in Lahu. Native Lahu speakers learning Dzongkha 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.