Batch Normalisation

I searched this topic and found a few posts from a couple of years ago.
Just wondered if there was, in the latest version, a way to ‘normalize or normalise’ a large number of audio files in one hit?

In Audacity 2.3.1 you can do that with a Macro:

Note that when using a Macro for batch processing files, the final command in the Macro should be an “Export” command.


If you don’t know this already - Normalizing files doesn’t necessarily make them all sound equally-loud.

If you want to loudness-match your files look into ReplayGain (or WaveGain or MP3Gain).

And, if you want to volume-match your music library (or other recordings that may already be normalized) you’ll find that ReplayGain (or similar tools) will tend to lower the loud tracks because the already-normalized quiet-sounding tracks can’t be boosted without clipping (distorting).

Thanks for that information. ( I did not know).
Think I might try ReplayGain as MP3Gain will not download on my computer for some reason.

[u]ReplayGain[/u] works by adjusting the volume at playback time so it has to be supported by your audio player. The files are pre-scanned and a ReplayGain “tag” is written into the file telling the player how much adjustment to make (up or down). I use Winamp (with ReplayGain) as my audio player, but winamp is “outdated” no longer being developed.

If you have an Apple device, [u]Sound Check[/u] works similarly so if you have an iPhone or iPod (and iTunes) you can simply switch-on Sound Check.

WaveGain and MP3Gain “permanently” change the loudness of the file so they work with any player.

There is a [u]ReplayGain plug-in[/u] and it does (optionally) alter the loudness of the file, so of course that will also work with any player.

MP3Gain will not download on my computer for some reason.

Hmmm… Works for me… I just downloaded mp3gain-win-1_2_5.exe from MP3Gain Downloads

If you have MP3s, MP3Gain can adjust the volume without decompressing/re-compressing the audio. If you load an MP3 into Audacity (or any “regular” audio editor) it gets decompressed. If you re-export as MP3 you are going through another generation of lossy compression. You don’t always hear quality loss but you should avoid doing that if possible.

If you are ripping CDs you can rip to WAV, then run WaveGain or use the Audacity ReplayGain plug-in and then convert/export to MP3 once, as usual.

The limitation of MP3Gain is that without decompressing you have to change the volume in 1.5dB steps. But, that’s still pretty-good and it usually gets you within 0.75dB of the target.

Thanks again for the reply.

My initial reason for some sort of sound normalisation is that I have many tracks (all mp3) that I load onto a USB and play in various vehicles.
As the tracks come from many different sources, the sound levels are not constant and vary by quite a margin.
As I think that most car audio systems will not support Replaygain, then this is not the way to go.
I have tried to install MP3gain from the link that you supplied but I still can’t get it to install. The installation seems to go o/k but when it gets to the ‘Finish’ screen another Windows installer box opens and tries to find a Microsoft Office file, the only way I can get out of this is to use Task Manager to end the MP3gain process.