Audio

The iPhone's headphones are similar to those of current iPods, but also incorporate a microphone. A multipurpose button in the microphone can be used to play or pause music, skip tracks, and answer or end phone calls without touching the iPhone. The 3.5 mm TRS connector for the headphones is located on the top left corner (as seen from front upright). Wireless earpieces that use Bluetooth technology to communicate with the iPhone are sold separately. The headphone socket on the iPhone is recessed into the casing, making it incompatible with some headphones without the use of an adapter.

The loudspeaker is used both for handsfree operations and media playback, but does not support voice recording.

With the iPhone firmware update 1.1.1, released in late September 2007, video can be output from the headset jack using a three-way jack plug. Component video at up to 576i and stereo audio can also be output from the dock connector using the Apple Component AV Cable.