What is loudness normalisation?
Firstly, what is loudness normalization? Well, it’s quite simple, really. The volume of each track played on an app such as Spotify, or iTunes (and now even YouTube) is the same, it’s at an equal loudness to every other track on the app. Quite simply, Loud songs become quieter and quiet songs become louder.
Well it’s actually quite a useful tool. You have the ability to listen to all your favourite music at the same perceived volume. You can listen to the tracks without thinking “that’s quieter than the last track” and heading for the volume knob. It basically makes everything a consistent volume.
It’s kinda good for mastering, it will hopefully mean that soon mastering can de done dynamically once again. These apps that we use everyday like Spotify, YouTube and Deezer all have loudness normalisation set as default, so everything is consistent for the user. Hopefully in the long term this will almost make mastering for pure loudness irrelevant, which mastering engineers would love!