How to list available audio output route on iOS

Question

Now i\'d like to list available audio output route in my iPhone app, something like this:

http://www.blogcdn.com/www.tuaw.com/media/2008/09/cb(iphone-101_-switch-bet

Answer 1

there are only 5 audio input routes (iOS5+):

kAudioSessionInputRoute_LineIn;
kAudioSessionInputRoute_BuiltInMic;
kAudioSessionInputRoute_HeadsetMic;
kAudioSessionInputRoute_BluetoothHFP;
kAudioSessionInputRoute_USBAudio;

and there are 9 audio output routes (iOS5+):

kAudioSessionOutputRoute_LineOut;
kAudioSessionOutputRoute_Headphones;
kAudioSessionOutputRoute_BluetoothHFP;
kAudioSessionOutputRoute_BluetoothA2DP;
kAudioSessionOutputRoute_BuiltInReceiver;
kAudioSessionOutputRoute_BuiltInSpeaker;
kAudioSessionOutputRoute_USBAudio;
kAudioSessionOutputRoute_HDMI;
kAudioSessionOutputRoute_AirPlay;

find more information here how you can check the availability of them in your application.