Pausing Audio file to play different Audio file - ios

Question

I'm using the systemMusicPlayer to play songs inside an app.
If a user pushes noiseButton on the Now Playing view, it will pause the systemMusicPlayer song audio file for 10 seconds to play the noiseButton audio file, and then pick back up on the systemMusicPlayer song audio file.
I'm able to get the systemMusicPlayer song audio file to pause and then pick back up after 10 seconds, but I am not able to get the noiseButton to play its sound in the 10 seconds.
I know the noiseButton audio file works
I'm NSLogging before and after the method that plays the noiseButton file
I'm not sure what I'm missing?
Here is my code:
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
musicPlayer = [MPMusicPlayerController systemMusicPlayer];
[self registerMediaPlayerNotifications];
// Construct URL to sound file
NSString *path = [NSString stringWithFormat:#"%#/background-music-aac.caf", [[NSBundle mainBundle] resourcePath]];
NSURL *soundUrl = [NSURL fileURLWithPath:path];
// Create audio player object and initialize with URL to sound
_audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:soundUrl error:nil];
}
- (void)willPlayClip {
[NSTimer scheduledTimerWithTimeInterval:10.0
target:self
selector:#selector(willPlayMusicInTenSeconds:)
userInfo:nil
repeats:NO];
}
- (void)willPlayMusicInTenSeconds:(NSTimer *)timer {
NSLog(#"Get ready to Play noise sound");
[_audioPlayer play];
NSLog(#"Play noise sound");
[musicPlayer play];
NSLog(#"Start playing again");
}
And the code inside the noiseButton for when it gets pressed:
if ([musicPlayer playbackState] == MPMusicPlaybackStatePlaying) {
[musicPlayer pause];
NSLog(#"Paused!");
[self willPlayClip];
} else {
NSLog(#"Already paused");
}

Answer 1

What AudioSession category are you setting? If you're not, refer to this documentation:
Audio Session Categories
I believe that you should get the desired behaviour if you set your session to AVAudioSessionCategoryAmbient:
The category for an app in which sound playback is nonprimary—that is, your app can be used successfully with the sound turned off.
This category is also appropriate for “play along” style apps, such as a virtual piano that a user plays while the Music app is playing. When you use this category, audio from other apps mixes with your audio. Your audio is silenced by screen locking and by the Silent switch (called the Ring/Silent switch on iPhone).
Give that a try if you're not already.