The audio engine’s singleton output audio node.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 3.0+
When this property is first accessed the audio engine creates a singleton on demand. Connect another audio node to the input of the output audio node, or obtain a mixer that is connected by default, using the
The AVAudioSesssion instance and/or the availability of hardware features determine whether an app can perform output. Check the output format of output node (specifically, the hardware format) for a non-zero sample rate and channel count to see if output is enabled.