Proving you can never tear down an Apple product far enough, iFixit has kept digging into [iPhone 4[(http://www.imore.com/iphone-4)'s noise cancellation and finally discovered... it uses the same Audience technology that powered Google Nexus One.
We like mysteries as much as the next guy, so we decided to dig further. Our friends at Chipworks just decapped the chip, and guess what they found? That’s right, an Audience low power audio signal processor.
They go on to praise iPhone 4's noise cancellation, saying it's better than any non-Audience device they've tested. They also wonder if Apple will stick with Audience going forward, or try to roll something of their own into an Apple A5 system-on-chip for iPhone 5?