Per-Scene Audio

This extension allows you to create scene-specific audio profiles for your presentation. You can adjust the microphone and system audio level for each scene.

You'll be able to access it by going to Extensions then selecting Per Scene Audio.

Use the Scene Selector drop-down to Add that you want to manage the audio. Each scene added will have their own system sound and microphone volume level adjustments. Scenes that you don't add will use the audio levels set in Default.

If you have the volume range range set above 100% in your Audio Settings, it will also reflect here.

Sync volume adjustment across scenes
Enable this to have the volume levels for all scenes added (including Default) automatically match any volume adjustment done.
Enable scene crossfade
Enable this to have a crossfade effect when switching from one scene to another, making transitions for audio volume between scenes smoother.