◆ AkAudioSessionSetActiveOptions

The behaviour flags for when iOS audio session is activated. These IDs are funtionally equivalent to the corresponding constants defined by the iOS audio session service backend (AVAudioSession). Refer to Xcode documentation for details on the audio session category options. The original prefix "AV" is replaced with "Ak" for the ID names.

参照
列挙値
AkAudioSessionSetActiveOptionNotifyOthersOnDeactivation 

Audio session activation option corresponding to the AVAudiosession's AVAudioSessionSetActiveOptionNotifyOthersOnDeactivation constant

AkiOSSoundEngine.h93 行目に定義があります。