Starts the audio engine.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 3.0+
Returns, by-reference, a description of the error.
true if the audio engine started successfully; otherwise,
Errors can occur when:
There is problem in the structure of the graph. Input can't be routed to output or to a recording tap through converter type nodes.
The driver failed to start the hardware