App volume goes quiet on iPad when using GKVoiceChat

Question

In my iOS game, I support push-to-talk using Game Center's GKVoiceChat.

When two iPhones are connected in a multiplayer match, this works as expected: the game's sounds are heard at roughly the same volume as the other player's voice (voice may be a tiny bit louder), and the game's volume is consistent whether or not the other player is using the push-to-talk function.

However, on an iPad, the volume of the game's sounds is drastically reduced; game sounds are played at roughly one quarter the volume of the voice sounds, so quiet that unless you put your ear to the speaker, you're hard pressed to tell that any game sounds are being played at all. (Voice sounds are at full volume.) In comparison, the iPhone's volume is deafening.

Here's how I'm setting up audio:

AVAudioSession* avSession = [AVAudioSession sharedInstance];

NSError *myError = nil;
[avSession setActive:YES error:&myError];
if(myError)
    NSLog(@"Error initializing audio session: %@", myError);

[avSession setCategory:AVAudioSessionCategoryPlayAndRecord
                 error: &myError];
if(myError)
    NSLog(@"Error setting audio session category: %@", myError);

[avSession setMode:AVAudioSessionModeVoiceChat
             error:&myError];
if(myError)
    NSLog(@"Error setting audio session mode: %@", myError);

// By default, AVAudioSessionCategoryPlayAndRecord sends audio output to the phone's earpiece; instead, we want to force it to the speakers
[avSession overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker
                             error:&myError];
if(myError)
    NSLog(@"Error changing audio port to speakers: %@", myError);

Then, later, when a multiplayer match is set up, we set up the voice chat like this:

self.myVoiceChannel = [[self myMatch] voiceChatWithName:@"allPlayers"];
[[self myVoiceChannel] start];
[[self myVoiceChannel] setActive:NO];
self.myVoiceChannel.volume = 1.0;

I've confirmed that commenting out the [[self myVoiceChannel] start] statement is sufficient to restore the iPad volume to the expected levels.

What's surprising is that [[AVAudioSession sharedInstance] mode] never gets set to AVAudioSessionModeGameChat---no matter when I expect it, it's always AVAudioSessionModeVoiceChat. From the AVAudioSession documentation, it seemed like when I initiated a GKVoiceChat, this would be changed automatically.

Any ideas why the iPad's audio would be mixed so differently from the iPhone?

Answer 1

It looks like this is a known issue since iOS 6.

The only options for working around it is to crank up your game's sounds during voice chats (on the iPad only, obviously).