What this means for learners
Cofán and Burushaski share 24 sounds — roughly 41% of Burushaski's inventory overlaps with Cofán. Shared sounds are ones a speaker already knows from their native language and will generally produce and perceive accurately without explicit training.
The 35 sounds found only in Burushaski represent the greatest pronunciation challenge for Cofán 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, Cofán has 13 sounds not used in Burushaski. Native Burushaski speakers learning Cofán 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.