Noise cancellation

Have you ever wondered how the noise cancellation works?? Smart Phones like Google Nexus One, iPhone 4, among many includes the hardware necessary to implement such technology improving considerably the signal transfered to our receiver, unfortunately not always works the other way around.

Anyway, people from Chipworks discovered the function of a small chip along the A4 processor inside the iPhone 4, this one:

Then, the company behind the scenes is Audience, whom works on various technologies to improve input audio signals and digital processing, in fact, they have a really good video which explains how the human auditive system somehow was translated into their DSP:

But this is a technical explanation of their technology, applied into real devices, this video shows the huge gap between having the signal processing and not: