Somehow my iPhone Simulator is unable to play sounds. First an app I\'m working on using AudioServicesPlaySystemSound()
stopped working.. I spent a while debug
if reactivating system sounds didn't work for you try this: launch audio-midi-setup, then configure your "built in output" to use 44.100Hz, 2 channels, 24 bits. (from http://www.cocos2d-iphone.org/forum/topic/4159)
somehow after a few days, my iphone simulator now wants 48.000Hz, 2 channels, 24 bits. just play with it for a bit and be warned that it might change randomly when plugging in headphones, going to standby, restarting, etc.
and here's a an off-topic hint: when you plug headphones into your iphone/ipad the buffer size might double (e.g. from 512bytes to 1024 bytes), make sure you don't rely on the buffersize you requested!