What this means for learners
Lue and Lao share 35 sounds — roughly 83% of Lao's inventory overlaps with Lue. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 7 sounds found only in Lao represent the greatest pronunciation challenge for Lue 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, Lue has 4 sounds not used in Lao. Native Lao speakers learning Lue 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.