1_Creat a folder(you can rename it if you want) here is Sound.
Click on the VNGE with a sound icon.A window will pop up.
2_Click on New Sound.
3_Choice the audio file for the scene.Click on GameSE and Create.
4_Click ok
5_Now you need to associate the audio file with the folder.Click on the plus here.
6_Click on Link
7_As at the beginning we had selected the Sound folder,
it was automatically associated with the audio file.
If you chose the wrong folder,no problem.Just click on Cancel,
select the folder and click on Link again.All good,you can click on OK.
8_Now you have to put the audio file in the timeline.
Open the timeline and look for Enabled.Click in the timeline (Middle Mouse Button) to the side of Enabled to put a frame.
9_If the folder is checked the frame is in (True), in unchecked is in (false)
IMPORTANT: Always put the False frame before the True frame.
False=Stop
True=Play
Sometime you have to put the (True) frame in the good part of the timeline
for the scene get the good timing with audio.
_You can try to check on PlayOnLoad if the audio don't play again when the scene restart.
_Click again on the VNGE sound icon for close the window.