One of the most interesting features on the iPhone 4S is Siri, the voice assistant. Every iPhone owner, be he an iPhone 4S owner or not is impressed by Siri and what it can do, but did you know how the “Raise to Speak†feature work?
The iPhone 4S has this little new infrared LED sensor that unlike previous iPhone IR proximity sensors that are only turned on when your face is near the phone to dim the display light and kill the keyboard till you`re done with your call, that infrared sensor searches for your face at all times.
It was not known why it does that at first ,but remembering Siri,and the “Raise to Speak” feature which means that Siri will be activated by pressing a button or raise the phone to your ear and speak, and that`s why the infrared sensor has to work at all times.
Now your personal assistant is ready to answer your questions. iFixit highlighted this previously unknown hardware part in the iPhone 4S in a video.
