The tour continues with the top left corner of the iPhone. Here's where you plug in the white earbuds that came with your iPhone.
This little hole is more than an ordinary 3.5-millimeter audio jack, however. It contains a secret fourth pin that conducts sound into the phone from the microphone on the earbuds' cord. Now you, too, can be one of those executives who walk down the street barking orders to nobody in particular. The iPhone can stay in your pocket as you walk or drive. You hear the other person through your earbuds, and the mike on the cord picks up your voice.
Incidentally, the tiny microphone nodule on the cord is more than a microphone; it's also an Answer/Hang Up clicker. See Answering Calls for the full scoop.
Get iPhone: The Missing Manual, 2nd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
