I’d like to normalize loudness of a full track according only to the volume of a specific portion of it. That is, applying the gain increase/decrease that Audacity applies when you do the classic Loudness Normalization effect to a region bigger than the selected (white) area on which Audacity is calculating the gain increase/decrease needed to achieve the target LUFS value in that region.
So for example I want -10 LUFS in a certain portion of a track and I don’t care if in other portions the LUFS are -8 or -12, but I want the volume to scale linearly and equally for every part of the track, without weird jumps in either up or down direction.
It would be enough to know how many dB the application of said Loudness Normalization effect automatically does (like by reading a report file) , undo the automatic normalization and adjust, this time manually, the volume on the desired (larger) area.
Or having a “real time” LUFS meter, or “analyze LUFS in selected area” feature would also be enough to work out by trial and error how many dB to add or remove to achieve what I’m talking about.
EDIT: I’ve seen that in Analyze → Contrast you can basically measure the dB of a selected region, or even better, 2 different regions (or same region in 2 different tracks, for example the same track before and after LUFS normalization) therefore you can know how much to adjust the volume of a track in order to match a desired target volume (adjust the volume with Effects → Bass and Highs (includes volume adjust too)).
Hopefully, LUFS measurement will be added in the future… That capability is obviously built-into LUFS normalization and it should be easy to expose it to us users.
It shouldn’t need to be real-time. It’s usually better to scan the file/selection.
And you wouldn’t need trial-and-error. A linear 2dB change makes a 2dB change to every measurement… Peak, RMS, LUFS, and the noise floor if you’re measuring that for audiobooks. (It’s not linear if you amplify into clipping.)
Of course you still have to check for clipping after amplification.
You’re describing two different tools. Most tools adjust a selection all at once to a setting. You sound like you want the effect of a sound engineer turning up and down the volume as the show progresses.
That’s an active compressor. Those are cool and highly desirable…and not fun.
Here’s a posting from someone trying to master compressor use.