What this means for learners
Aghem and Luganda share 26 sounds — roughly 53% of Luganda's inventory overlaps with Aghem. 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 Luganda represent the greatest pronunciation challenge for Aghem 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, Aghem has 23 sounds not used in Luganda. Native Luganda speakers learning Aghem 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.