SKAction playSoundFileNamed doesn't work after receiving two consecutive phone calls

Question

I am trying to figure out why playSoundFileNamed doesn't work after receiving two consecutive phone calls. Actually it works only after the first phone call is received. Reproducing steps are:

1. Start a game
2. Wait for a phone call and go to background
3. Phone call is finished (declined or interrupted by caller)
4. Returning to foreground

After this, playing the sound from touchesBegan still works.

When I repeat the steps from above (first step is skipped), mechanism from touchesBegan stops working. Not sure why is this happening...Here is the code which can produce described behaviour:

@interface GameScene()

@property (nonatomic, strong) SKAction *sound;
@end

@implementation GameScene

-(void)didMoveToView:(SKView *)view {
    self.sound = [SKAction playSoundFileNamed:@"sound1.wav" waitForCompletion:NO];
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    /* Called when a touch begins */
    [self runAction:self.sound];
}
@end

I know there are some questions related to this on SO, but given answers are related to workarounds. I am not interested in workaround, but rather why is this happening? Is it somehow related to AVAudioSession ? (probably not) I know I could use AVAudioPlayer as a workaround, but still not sure how much is that performant for playing a lot of simple short sounds...

Answer 1

The SKAction playSoundFileNamed is buggy in regards to the app transitioning between background and foreground. That's the reason why you are having this issue. I am not sure if this problem has been corrected in iOS 9.

As for a workaround, you stated you're not interest but I will include one for completion's sake. Use AVAudioPlayer instead of SKAction. AVAP has the ability to stop and start (using its delegates) based on your app's state.