How to find out if an external headset is connected to an iPhone?

Question

Is it possible to detect that the user has an external headset plugged into the iPhone's 3.5mm connector or the 30-pin connector? I want to output audio only to an external audio device, and keep silent if nothing is connected.

Answer 1

The answer is very similar to the answer to this question, but you'll want to get the kAudioSessionProperty_AudioRoute property instead.