Only in Nepali 42
What this means for learners
Nepali and Magahi share 32 sounds — roughly 43% of Magahi's inventory overlaps with Nepali. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 18 sounds found only in Magahi represent the greatest pronunciation challenge for Nepali 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, Nepali has 42 sounds not used in Magahi. Native Magahi speakers learning Nepali 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.