Does anybody know of any limitations on the sounds that can be played when an iPhone app receives a push notification? Specifically, is there a maximum sound length?
Also, I am assuming that the volume of the sound will match whatever the user has set their ringer volume to, and if set to vibrate mode, the phone will vibrate instead of playing a sound. Is this correct?
I have tested the maximum length of a push notification audio alert, which not surprisingly turned out to be 30 seconds. Any longer audio files will result in the built-in Tri-tone alert being played instead.
I don't know for sure, but based on various API limitations I would guess the length would be 30 sec. max. And yes, the volume of the ringer is the volume of the sound. Same with vibrate mode
You may have to consider "Notification Payload" for that.You can also have Custom Alert Sounds. See this:Notification Payload
Updated reference to Apple's documentation for 30 seconds.
Here's the reference in Apple's documentation (30 seconds is correct): https://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/IPhoneOSClientImp/IPhoneOSClientImp.html#//apple_ref/doc/uid/TP40008194-CH103-SW6
来源：https://stackoverflow.com/questions/1463599/limits-on-iphone-push-notification-sounds