Linux Multimedia Hacks

Normalize the Volume of Your Audio Files

Use the normalize tool to adjust the volume of audio files so they all have the same volume.

Many, if not most, people find TV commercials (or at least some of them) annoying. One particularly annoying trait of some TV commercials is their volume setting. The volume of the TV is set perfectly for the show you are watching, but the moment the commercial break starts, the advertising blares through the speakers, forcing you to adjust the volume again. Of course, this means that once the commercials are finished, you have to adjust the volume back to a level suitable for the program.

Music often suffers from the same volume issues that plague TV commercials—some CDs are recorded with particularly low volume, others with a particularly high volume. If you listen to your music on Random (or using a tool such as IMMS [Hack #19] ), you end up fiddling with the volume control to account for these differences. Luckily, under Linux there is an excellent tool called normalize that can analyze a series of audio files and adjust them so they are all the same volume.

normalize has been around for years, and many other multimedia projects use it behind the scenes. As a result, your distribution probably already has it packaged (often called normalize or normalize-audio). If your distribution doesn’t have normalize, download it from the official site at http://www1.cs.columbia.edu/~cvaill/normalize and compile and install it according to the provided documentation. ...