An array of available output data sources for the current audio route.
- iOS 6.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
An array of
AVAudio objects representing available output sources, or
nil if switching between multiple output sources is not currently possible. This feature is supported only on certain USB accessories.
You can observe changes to the value of this property by using Key-value observing.