There was one small, 3mm x 3mm chip that we weren’t able to identify during our teardown. It was white-labelled, meaning Apple asked the manufacturer to remove their branding from the package to make it difficult for folks like us to identify.
—Unveiled: Audience powers iPhone 4′s impressive noise cancellation
So, iFixIt was able ti identify every part but this one. Why would Apple have asked Audience to remove their branding from the chip? Are they that particular about even the internals of their devices? Curious.