Instructions here apply to Windows PCs, but Mac users have a similar utility calledMP3Gain Express for Mac.
These instructions show how to configure MP3Gain to displayjustfilenames.
Select theOptionstab at the top of the screen.

Select theFilename Displaymenu item.
SelectShow File only.The files you choose will now be easy to read in the main display windows.
Select files to add to the MP3Gain queue.

Do this manually or use standardWindows keyboard shortcuts.
(CTRL+Ato select all files in a folder,CTRL+mouse buttonto queue single selections, etc.)
Once you’re happy with your choices, select theOpenbutton to continue.

To add a large list of MP3 files from multiple folders on your hard disk quickly, selectAdd Folder.
This will save a lot of time navigating to each folder and highlighting all the MP3 files.
Some normalizing programs resample each file, which can decrease sound quality.

Normalize Your Music Tracks
Now it’s time to normalize the selected files.
Just as in the previous step, there are two modes for applying the normalization.
After MP3Gain has finished, the list will show that all files have been normalized.
Soundcheck
After the files have been normalized, it’s time to do a soundcheck.
ChooseSelect All Files(or use the keyboard shortcutCTRL+A).
Right-click anywhere on the highlighted files and choosePlayMP3 Filefrom the pop-up menu to launch your default media player.
Listen to your songs.
If you’re happy with the volume regularity, enjoy your music!
FAQ
You typically can’t edit an MP3 with your system’s built-in applications.
Instead, you oughta useaudio or music editing software.
Download software that supports audio format conversion, such asVLC Player.
SelectMedia>Convert/Save> choose the WAV file > selectConvert/Save> setMP3as the new format.
iPhones generally store files with their associated appsso audio in Messages is saved in Messages directories, etc.