Its Siri which becomes the most talked hot favorite function of the new iPhone 4S and since its inception everyone is indulged in getting its voice assistance. We reported that Siri port on iPhone 4 and iPhone 3GS was demonstrated followed by Apple testing Siri on older devices and then Apple calling it off for older devices at the moment. Today we had a strange discovery made by iFixit regarding iPhone 4S Proximity Sensor according to them the proximity sensor installed in iPhone 4S is much different from iPhone 4 as it keeps on detecting when you are nearby so it can put Siri ready to respond as you speak.
Therefore its not only software which has to be ported but rather specialized hardware is used in iPhone 4S which is not available in older Apple devices. According to iFixit,
“During our iPhone 4S teardown, iFixit buddy Markus noted that the new iPhone had a rather unusual-looking black component next to the ambient light sensor. We didn’t make much of a fuss about it since we were knee-deep in disassembly pictures, but the little black box certainly piqued our curiosity.
Now that the teardown is wrapped up, we’ve re-opened the mystery and made a neat discovery about the 4S: that black component is an infrared LED, and the little bugger almost always wants to know if you’re nearby.”
Therefore the proximity sensor keep waiting on activated seen as you near you self to the device Siri starts expecting you. So this behavior even if Siri is ported to older devices will not work due to lack of hardware. You can review the tear down of iPhone 4S Siri components in iFixit video below,