Of course, I use the VU meters of Audacity for all my project, and I made a tuto to explain it 8 years ago, but it was 8 years ago...
 
	
		
	
	So to summarize:
 
	- We need a VU meter for each audio track, with a cursor for tuning the global volume of the track.
 
	- We need a VU meter for the audio output of the whole project, with a cursor for tuning the final volume of this audio output.