Play alert sound (same as default message ringtone)
Is it possible to play some default sounds, such as when an incoming SMS/push is received?
If iOS SDK does not bundle these sound files, where can I download the same sounds?
Yes it is possible, but they use undocumented enum values, that means you should not use it on AppStore apps.
AudioServicesPlaySystemSound(1003);
iOS SDK does not bundle these sound files, but you can find them on the device in the /System/Library/Audio/UISounds/ folder. However, I believe these files are copyrighted.
Why not create a sound yourself?