second file match current volume level of first file

How do I make 2 files have the same ‘volume level’?

Here the scenario: I want File-B (the secondary file) to have the same volume as File-A (the primary file)

I’ve found previous questions and answers for changing multiple files to the same volume, by giving all the files a new volume (dB).
However, that’s not what I’m trying to accomplish: File-A should not be modified.


Audacity 3.1.3
Windows 10

We should get a little closer to the application. If you’re creating an audiobook, then you want the legacy, plain RMS Loudness settings. If you plan on podcasting, it’s possible you want the newer LUFS system which takes into account ear oddities. They’re very different.


Actually, there’s another layer. If you have two very different sound files with different performances, surroundings, and backgrounds, and the goal is a graceful listening experience, then you want a talented mixer human to look at it or listen to it. It’s less likely that a software solution is going to work.


If you want the volume envelope of File-B to closely resemble File-A,
that can be done with an envelope-follower, e.g Steve’s Dynamic-Mirror plugin …

I found on online [u]LUFS Loudness Measurement Tool[/u].

You can measure the loudness of “A” and then run Audacity’s Loudness Normalization to match.
If that doesn’t work “perfectly” you use the Amplify effect and adjust by ear. (If “B” is too loud you can enter a negative dB value into the Amplify effect.

There is one potential issue. Since peaks don’t correlate with perceived loudness, if you are boosting “B” you might push the peaks into clipping (distortion).

There are plug-ins for measuring LUFS, including from the Youlean link above, but the Youlean plug-in and dpMeter don’t seem to work since the latest Audacity updates.

Or, [u]Goldwave[/u] (a commercial “competitor” to Audacity) has loudness measuring and loudness adjustment built-in. And there is a fully-functioning free trial so you can use it for awhile without buying it.

I bought GoldWave a long time ago, I think before Audacity existed. At least before I knew about Audacity. I probably wouldn’t buy it now but it comes with lifetime upgrades so the per-year cost has been almost zero!