Using the Application recording mode will detect and record any audio stream from any of the monitored applications. This is the audio stream the application makes, before it is sent to your computers audio subsystem. It's your computers audio subsystem that descides if it will be played or not - ie the stream might be muted or volume turned down.
You can see which application the stream is being produced by on the Properties form. Select the recording item and then Menu -> Properties. Look at the source field.
The monitored applications can be modified from their defaults by looking at Settings > Recording Settings > Apps button.
From CRS @ 22 May 2017 09:05