On iPhone5 got 3 input channels (not 1)

Question

On iPhone5 (and probably iPad mini) this code returns 3 input channels

UInt32 numInputChannels;

// Check the number of input channels.
UInt32 size = sizeof(numInputChannels);
UInt32 newNumChannels;
CheckError(AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareInputNumberChannels,
&size,
&newNumChannels), "Checking number of input channels");

numInputChannels = newNumChannels;

My question is why 3? I checked this code on iPhone4S, iPod4, iPad2, iPad3 - it returns 1 - this is microphone

But what are other 2?

Answer 1

iPhone 5 has three inbuilt microphones for better sound recording, in the keynote they have explained that. READ