What this means for learners
Maasai and Lahu share 17 sounds — roughly 37% of Lahu's inventory overlaps with Maasai. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 29 sounds found only in Lahu represent the greatest pronunciation challenge for Maasai 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, Maasai has 26 sounds not used in Lahu. Native Lahu speakers learning Maasai 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.