What this means for learners
Sinhalese and Finnish share 25 sounds — roughly 47% of Finnish's inventory overlaps with Sinhalese. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 17 sounds found only in Finnish represent the greatest pronunciation challenge for Sinhalese 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, Sinhalese has 28 sounds not used in Finnish. Native Finnish speakers learning Sinhalese 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.