Q:

Can I download an audio file and use it for push notification sound in iOS?

I want to download a file and store it somewhere in my app, for example NSUserDefaults, and then play it with a push notification.
Is it possible? If so, where is the best place to store this audio file?
Any help is appreciated, thanks in advance

A:

Yes, you can do this, but it's not so much "best place" as "only place": /Library/Sounds. Here is the appropriate documentation.
Specifically this:

You can assign the filename of a nonlocalized custom sound in the app’s main bundle (or data container) or you can assign UILocalNotificationDefaultSoundName to get the default system sound.

And this:

For remote notifications in iOS, you can specify a custom sound that iOS plays when it presents a local or remote notification for an app. The sound files can be in the main bundle of the client app or in the Library/Sounds folder of the app’s data container.

