What this means for learners
NDUT and Hakka Chinese share 11 sounds — roughly 23% of Hakka Chinese's inventory overlaps with NDUT. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 36 sounds found only in Hakka Chinese represent the greatest pronunciation challenge for NDUT 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, NDUT has 23 sounds not used in Hakka Chinese. Native Hakka Chinese speakers learning NDUT 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.