How to play audio from earpiece in iPhone?

Question

I want to play audio from earpiece . I tried the solution provided in this : Play Audio but it is not working. I also tried

 NSError *error = nil;
        AVAudioSession *session = [AVAudioSession sharedInstance];
        [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];
        [session setActive: YES error:nil];

        AVAudioSessionPortDescription *routePort = session.currentRoute.outputs.firstObject;

        [session  overrideOutputAudioPort:AVAudioSessionPortOverrideNone error:&error];

Answer 1

I play audio from earpiece by writing these lines in my ViewController's viewDidLoad method:

NSError *error = nil;
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];
    [session setActive: YES error:nil];
    [session  overrideOutputAudioPort:AVAudioSessionPortOverrideNone error:&error];