Play sound in local notification

I have used Local Notification in my app an successfully generated an alert at correct time..

But when i tried following code for playing sound it does not play....

localNot.soundName =@"Ghulam Ali-Chamkte Chaad Ko.mp3";

Can anyone tell me the reason....Does the playing length of sound 开发者_Go百科file affects

According to the Apple Developer Documentation, you need to use "aiff", "caf" or "wav" files.

The link provided shows some ways of converting audio to these formats on your mac.