Sound seems to be easy, just copy from the examples:
Create a soundID
AudioServicesCreateSystemSoundID (soundFileURLRef, soundID);
and play the sound:
AudioServicesPlaySystemSound (soundID);
and wav and caf and aif is allowed, what could be more easy?
Until you hear your sound played! If it played at all. What you forget (at least I did) is this line:
The audio data in the file must be in PCM or IMA/ADPCM (IMA4) format.
What can be that stuff????
It took me a while to find out how to do that:
In the terminal window, find your soundfile and do:
macbook: contrechoc$ afconvert -f caff -d ima4 trill.wav
only this reformatting will make your soun play well.
But there is more:
The above lines of code don’t show this little detail:
what is a soundID? Well:
SystemSoundID soundID;
You make it like this:
mainBundle = CFBundleGetMainBundle ();
soundFileURLRef = CFBundleCopyResourceURL (mainBundle, CFSTR ("mySound"), CFSTR ("caf"),NULL );
But wait a minute: I know of NSString, but what is all this: CFSTR ???
And why is there no @ in front??
Ok, now you are in the apple jungle: CFSTR comes from other earlier Xcode environments, the MACOS etc….
Later on came NSString….. 
You have to cast this CFSTR parameter if you are carrying an NSString, which is what you want because you want to make a nice object:
(CFStringRef) soundName is of type CFSTR if soundName is of type NSString:
Knowing this you can make a nice drumpad app, with buttons carrying images of snares and base drums and sounds attached on the “action” method of these views.
Example with sounds attached to a button. The buttons are generated in a grid, and stored in an NSArray.
