What this means for learners
SRE and Cham share 26 sounds — roughly 70% of Cham's inventory overlaps with SRE. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 9 sounds found only in Cham represent the greatest pronunciation challenge for SRE 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, SRE has 11 sounds not used in Cham. Native Cham speakers learning SRE 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.