What is the Scene View's Audio Play Toggle For?

There is a little audio icon in the Scene View's icon bar (above the scene content). The text says "Toggles audio on or off." When enabled it will cause any AudioSource with Play On Awake set and an Audio Clip loaded to begin playing back. The "Mute audio" button in the Game View will actually mute this audio (disabling/enabling a playing AudioSource will also stop the audio it's playing until you next refocus the Scene View. Here is the decompiled code that does it (located in UnityEditor.SceneView via the MonoDevelop Assembly Browser):

Spoiler: UnityEngine.SceneView.RefreshAudioPlay()

Code (CSharp):

1.     private void RefreshAudioPlay ()
2.         {
3.             if (SceneView.s_AudioSceneView != null && SceneView.s_AudioSceneView != this && SceneView.s_AudioSceneView.m_AudioPlay) {
4.                 SceneView.s_AudioSceneView.m_AudioPlay = false;
5.                 SceneView.s_AudioSceneView.Repaint ();
6.             }
7.             AudioSource[] array = (AudioSource[])Object.FindObjectsOfType (typeof(AudioSource));
8.             AudioSource[] array2 = array;
9.             for (int i = 0; i < array2.Length; i++) {
10.                 AudioSource audioSource = array2 [i];
11.                 if (audioSource.playOnAwake) {
12.                     if (!this.m_AudioPlay) {
13.                         audioSource.Stop ();
14.                     }
15.                     else {
16.                         if (!audioSource.isPlaying) {
17.                             audioSource.Play ();
18.                         }
19.                     }
20.                 }
21.             }
22.             AudioUtil.SetListenerTransform ((!this.m_AudioPlay) ? null : this.m_Camera.transform);
23.             SceneView.s_AudioSceneView = this;
24.         }

Does anyone have any idea what you would actually use this feature for?

 

No but interested

 

AFAIK that's for when you're setting up ambient audio sources and such in a level, you can hit that button to preview what it sounds like without having to hit play.

 

I guess that makes sense. Feels very odd, given that it would turn on everything in the scene. Perhaps a better name for this would be helpful. Something like "Enable Ambient (Play On Awake) Audio Playback".

 

Thanks @SonicBloomEric for posting the decompiled code! I used it as a starting point when implementing SceneView audio for my custom audio engine as demonstrated here: https://twitter.com/fuzzblob/status/1139654198717321216