Constant Gain Differential

That’s going to be harder than you think. You want the loudness of the two presentations to maintain a relation to each other. Loudness isn’t one thing. It’s condition over time and there’s no shortage of different ways to calculate it and apply the results of the calculation.

For one example, we have a new tool for setting RMS (Loudness) for audiobook readings. Loudness is one of the specifications you have to meet for submission so someone will pay you. But it doesn’t change over time. It looks at your whole chapter, figures out the overall loudness, corrects it if needed, dusts off it’s hands and goes home. In general, that’s how the audiobok company does it, so everybody wins.

You can see if that helps you. Scroll down to where it says “Get and install RMS Normalize.” That’s the name of the tool.

https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/1

As a side note. You know most people can’t hear a 3dB change, right? That’s like changing the volume on your iPod 1/3 click.

Koz