public static void StopAudioOutput()

Has no effect if audio output thread is not running.

Note: When audio output thread is stopped AudioSource.time, AudioSource.timeSamples and AudioSettings.dspTime are not changing. At the same time AudioSource.isPlaying remains true if it was true before stopping audio output thread. Also MonoBehaviour.OnAudioFilterRead(float[], int) callback, Native Audio Plugins callbacks and Audio Spatializer callbacks are not being called.