This is the program i use to level the volume on my bumpers , Since i use Passthrough audio with kodi the volume adjustments in Preshow wont work with some of my bumpers so i found this to level them all to the same volume . Its convenient to use you can pick a file to match the rest of your bumpers to or pick one of the various other ways to level the volume.. The FREE version has a limit of ONE Minute of audio , But is plenty in most cases for bumpers if longer is needed You can purchase or feel feel free to contact me and i can help... Hope this program helps on keeping those rouge bumpers from popping your eardrums ...

Additional info:

The application can adjust audio volume in various ways. It matches the volumes of separate files. If you have several songs with different volume levels you want to write to a CD, use this software to adjust volume levels of each song so they sound similar. The target volume level can be average of all tracks, or just as same as the volume of other audio or video file.

The application can also maximize volume. Each file will be amplified as loud as possible without changing its dynamic range and clipping audio track.

You can also change the sound level directly, by specifying a custom dB value or percentage.