(Ref.https://app.nomalab.com/help/what-is-the-difference-between-a-master-zone-blue-zone-and-a-capsule-zone-purple-zone difference between a master zone and a delivery zone)
It is quite possible to play audio files wether or not they are separated from the video.
In a master zone :
When the files are uploaded, you just need to click on « play ».
The player will then display the curve of the audio you want to check.
If your zone has a primary media (a video file). You can return to the video at any time by clicking on « Return to main media ».
In a delivery zone :
You just need to click on the « show » button to the right of the audio file.
If you delivery zone contains a main media (a video) you can return to this media at any time by clicking on « hide ».