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Cocos2D Audio – CocosDenshion


In this iDevBlogADay tutorial I will show you how to add music and effects to your iPhone game. You will learn how to play effects passing pan, pitch & gain parameters, preload background music & adding steps effects. We will use CocosDenshion to achieve this. This audio library is already included in Cocos2D, so you will not need to download or configure anything! For a complete overview of what CocosDenshion is please read its FAQ at

Supported formats

CocosDenshion supports the following audio formats:

MP3 (IOS 3.0 onward)
IMA4 (1/4 the size of a WAV file)

To convert a WAV file to IMA4:

Open Terminal and type:
afconvert -f caff -d ima4 mysound.wav

The code

Add this line at the beginning of your implementation file (below #import “HelloWorldLayer.h”)

#import "SimpleAudioEngine.h"

Add these lines inside your init method

//Preloading background music
[[SimpleAudioEngine sharedEngine] preloadBackgroundMusic:@"background.mp3"];

//Preloading effects
[[SimpleAudioEngine sharedEngine] preloadEffect:@"asphalt1.mp3"];

//Play background music
[[SimpleAudioEngine sharedEngine] playBackgroundMusic:@"background.mp3"];

//Play effect
[[SimpleAudioEngine sharedEngine] playEffect:@"effect.wav"];

//Play effect advanced settings
[[SimpleAudioEngine sharedEngine] playEffect:stepEffect pitch:1.0f pan:0.0f gain:0.6f];

pitch: 0.5f (half the speed) to 2.0f (twice the speed). 1.0f to play normal speed
pan: -1.0f fully left, 1.0f fully right. 0.0f centered.
pitch: 1.0f unchanged. Each division by 2 equals a -6dB reduction

//Pause background music
[[SimpleAudioEngine sharedEngine] pauseBackgroundMusic];

// Background music volume
[CDAudioManager sharedManager].backgroundMusic.volume = 1.0f;

// Get noticed when background music stops
[[CDAudioManager sharedManager] setBackgroundMusicCompletionListener:self selector:@selector(backgroundMusicFinished)]; 

// Loop background music
[[CDAudioManager sharedManager] playBackgroundMusic:@"background.mp3" loop:YES];
[CDAudioManager sharedManager].backgroundMusic.numberOfLoops = 3; //To loop 3 times

Adding Steps:

Use this code to add steps sounds to your characters.

Add this line to your interface file:

CCLabelTTF *label;
BOOL bStepEffect;

Add these functions above your init method:

-(void) backgroundMusicFinished{

    CCLOG(@"Background Music Completed");
    [label setString:@"Music completed"];


-(void) playStepEffect {

    [[SimpleAudioEngine sharedEngine] playEffect:@"asphalt1.mp3" pitch:1.0f pan:0.0f gain:0.6f];


- (void) playSteps: (ccTime) dt{

    [self playStepEffect];


-(BOOL) ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event { 

    CCLOG(@"Start/Stop Steps");

    if(bStepEffect == FALSE){

        [self playStepEffect];
        [self schedule:@selector(playSteps:) interval:0.3f];
        bStepEffect = TRUE;


        [self unschedule:@selector(playSteps:)];
        bStepEffect = FALSE;


    return TRUE;


Finally, add the following lines inside your init method:

bStepEffect = FALSE;

self.isTouchEnabled = YES;
[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];

Positional Audio:

@Crocodella has an excellent article explaining what positional audio is and its benefits.
“The term itself is pretty self-explanatory, in that positional audio is the simulation of the ability that we humans have to judge the approximate distance and direction of a sound source, and also the physical properties of sound based on the environment.” You can find the complete tutorial here:

Professional Music:

Our game music is being composed by @wblackall, he’s doing an amazing job, so I recommend him if you plan on adding background music to your game.

Click here to download the source code of this tutorial