Journal Thelasko's Journal: Normalizing MP3 Files

I have a bunch of old MP3 files that have varying perceived loudness. I used some tools to correct this over a decade ago, but for some reason they didn't get archived.

I tried using the Linux utility Normalize-Audio to correct the loudness issue. This software seems to be full of bugs. While it evaluates a batch of files, it only corrects the last file in the batch. That means each file has to be corrected individually. Upon correcting a file, there is no discernible difference. Running the program again outputs the file still needs correction. Bottom line, it doesn't work at all.

I dug up an old .deb file for mp3gain. Unfortunately, I had similar results to Normalize-Audio. It seems to set a flag in the MP3 tag, but it has no effect on the file's playback.

The best way to normalize an MP3 is Audacity. It actually decodes the MP3, normalizes it, and reencodes it. It can be done very simply with a macro GUI. Don't bother with other options. This is the only way.

Audacity's denoise effect is also amazing. Just highlight a quiet part, where the noise is obvious, run the tool, and click the noise selection tool. Select all and run the tool again and click ok.