“…No toxic effects or deterioration in bone conduction in comparison with the contralateral ear were detected during a 13-year observation period. 9 The absorption of metallic elements from the middle ear into the perilymph can occur through the round window, the oval window, or the bony otic capsule. Although it has not been clearly demonstrated yet, it is speculated that in the oval window region Al can pass through the very thin SFP, the annular ligament, or the bony walls of the oval window niche.…”