iPhone best Audio Compression for in Game Sounds like Shoot or Hit

Hello, well i'm looking for the best compression for playback Shoot & Hit Sounds on iPhone... Is 16 bit 44100 Hz Mono better in performance than 16 bit 22500 Hz Mono ? or is 8 bit 22500 Hz better performance wise ???

and what is if i want to alter the Pitch & Volume of the Sound ??? So if i change the Pitch & Volume @ moment i get some framerate drops... here is how i change the Sound:

function ShipSpeed (Speed : float) {
		Ship.ShipSpeed = Speed;
		Ship.audio.pitch = Speed;
		Ship.audio.volume = Speed;

}

many thanxx for your help

Neither do I have an answer. Just launch the Activity Monitor from XCode (Run->Start with Performance Tool->Activity Monitor) and try out sounds with different formats. Observe how much CPU your application is consuming.

Profiling your application is always the best way to figure it out.

8 bit at 22500 HZ will kill sound quality in any circumstance. I would do 8 bit at 44100 if the audio file is pretty loud and noisy thing. if it's a quieter type song I would do 16 bit at 44100 HZ. 22500 HZ just sounds really bad unless you are recording an orchestra if I remember right.