kAudioSessionCategory_AmbientSound
For an app in which sound playback is nonprimary—that is, your app can be used successfully with the sound turned off.
Declaration
var kAudioSessionCategory_AmbientSound: Int { get }Discussion
This category is appropriate for “play along” style apps, such as a virtual piano that a user plays over iPod audio. When you use this category, audio from other apps mixes with your audio. Your audio is silenced by screen locking and by the Silent switch (called the Ring/Silent switch on iPhone).
This category is equivalent to the ambient category provided in the AVFoundation framework.