kAudioQueueProperty_IsRunning

Value is a read-only UInt32 value indicating whether or not the audio queue is running. A nonzero value means running; 0 means stopped. A notification is sent when the associated audio queue starts or stops, which may occur sometime after the Audioqueuestart(_:_:) or Audioqueuestop(_:_:) function is called.

var kAudioQueueProperty_IsRunning: AudioQueuePropertyID { get }