The kid screams at 3000 Hz and the mother comes to aid.
The mother screams at 1400 Hz and the father comes to aid.
The father groans at 100 Hz and no one comes.
“Hey, was this a bear? Let’s get away from here.”
Steve’s replay gain tool might also be useful.
It set’s the loudness according to a preference level, after a-weighting the content.
Select all tracks, open the plug-in and choose “normalize”.
The songs should now be at the same relative loudness.
You can afterwards use amplify (with all tracks selected" to increase the volume a bit in order to come near 0 dB.
That is, if Amplify proposes 3 dB then the loudest track (peakwise) has -3 dB. Thus, you can enter the value 2 dB and all tracks are amplified by that. The norm is in this case the loudest track which now has -1 dB.
The relationship between the tracks is the same as after the replaygain normalisation.
Don’t use normalize after replay gain. All tracks would have -1 dB in this case.