What this means for learners
Kpelle and Igbo share 32 sounds — roughly 49% of Igbo's inventory overlaps with Kpelle. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 33 sounds found only in Igbo represent the greatest pronunciation challenge for Kpelle 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, Kpelle has 17 sounds not used in Igbo. Native Igbo speakers learning Kpelle 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.