I got the following code:

- (id)init {
    if (self = [super init]) {
        UInt32 sessionCategory = kAudioSessionCategory_MediaPlayback;
        AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(sessionCategory), &sessionCategory);    

        UInt32 audioRouteOverride = kAudioSessionOverrideAudioRoute_Speaker;
        AudioSessionSetProperty (kAudioSessionProperty_OverrideAudioRoute,sizeof (audioRouteOverride),&audioRouteOverride);

        [[AVAudioSession sharedInstance] setDelegate:self];
        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
        [[AVAudioSession sharedInstance] setActive:YES error:nil];
    }
    return self;
}

But somehow the sound does not want to come out of the speakers, can someone see what I am doing wrong?

The code I use for playing is:

AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFilePathURL error:nil];
[player prepareToPlay];
[player setVolume:1.0];
[player play];