[AVAudioSession sharedInstance];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(audioRouteChangeListenerCallback:)
name:AVAudioSessionRouteChangeNotification
object:nil];

- (void)audioRouteChangeListenerCallback:(NSNotification*)notification
{
NSDictionary *interuptionDict = notification.userInfo;

NSInteger routeChangeReason = [[interuptionDict valueForKey:AVAudioSessionRouteChangeReasonKey] integerValue];

switch (routeChangeReason) {

case AVAudioSessionRouteChangeReasonNewDeviceAvailable:
NSLog(@"AVAudioSessionRouteChangeReasonNewDeviceAvailable");
NSLog(@"Headphone/Line plugged in");
break;

case AVAudioSessionRouteChangeReasonOldDeviceUnavailable:
NSLog(@"AVAudioSessionRouteChangeReasonOldDeviceUnavailable");
NSLog(@"Headphone/Line was pulled. Stopping player....");
break;

case AVAudioSessionRouteChangeReasonCategoryChange:
// called at start - also when other audio wants to play
NSLog(@"AVAudioSessionRouteChangeReasonCategoryChange");
break;
}
}

ios 耳机插入拔出检测