Posted when the primary audio from other applications starts and stops.
UIKit for Mac 13.0+Beta
Subscribe to this notification to ensure that your app is notified when optional secondary audio muting should begin or end. This notification is sent only to registered listeners that are currently in the foreground and have an active audio session.
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.