Detecting if headphones are plugged into iPhone

Question

Does anyone know if you can detect if headphones are plugged into the iPhone, and if they aren't - disable sound from your application.

I think I could manage disabling sound, but the detection part I have yet to find anything on.

Thanks

Answer 1

With this code you can detect the changes between:

• MicrophoneWired
• Headphone
• LineOut
• Speaker

Detecting when an iOS Device connector was plugged/unplugged

Note: Since iOS 5 part of the "audioRouteChangeListenerCallback(...)" behavior is deprecated but you can update it with:

// kAudioSession_AudioRouteChangeKey_PreviousRouteDescription -> Previous route
// kAudioSession_AudioRouteChangeKey_CurrentRouteDescription -> Current route

CFDictionaryRef newRouteRef = CFDictionaryGetValue(routeChangeDictionary, kAudioSession_AudioRouteChangeKey_CurrentRouteDescription);
NSDictionary *newRouteDict = (NSDictionary *)newRouteRef;

// RouteDetailedDescription_Outputs -> Output
// RouteDetailedDescription_Outputs -> Input

NSArray * paths = [[newRouteDict objectForKey: @"RouteDetailedDescription_Outputs"] count] ? [newRouteDict objectForKey: @"RouteDetailedDescription_Outputs"] : [newRouteDict objectForKey: @"RouteDetailedDescription_Inputs"];

NSString * newRouteString = [[paths objectAtIndex: 0] objectForKey: @"RouteDetailedDescription_PortType"];

// newRouteString -> MicrophoneWired, Speaker, LineOut, Headphone

Greetings

Answer 2

http://developer.apple.com/iphone/library/samplecode/SpeakHere/Introduction/Intro.html

In this project there is a code-snippet where it pauses recording if the headphones is unpluged. Maybe you can use it to achieve your result.

Good luck!

(edit)

You will have to study the SpeakHereController.mm file.
I found this code in the awakeFromNib method

// we do not want to allow recording if input is not available
error = AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable, &size, &inputAvailable);
if (error) printf("ERROR GETTING INPUT AVAILABILITY! %d\n", error);
btn_record.enabled = (inputAvailable) ? YES : NO;

// we also need to listen to see if input availability changes
error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioInputAvailable, propListener, self);
if (error) printf("ERROR ADDING AUDIO SESSION PROP LISTENER! %d\n", error);