Photo by Rainer Holz/Zefa/Corbis

You're listening to your favorite Pink Floyd CD on your home stereo when you accidentally hit the “change CD” button on the control panel. All goes quiet for a bit as your CD player urgently shifts to play whatever is in the next tray. With dread, you desperately reach for the volume knob, but it's too late—your speakers blast the latest Green Day album. Reacting like you were just pricked by a pin, your hand jolts to the volume knob and turns it down. You breathe a sigh of relief. But that's not the end of it. Ten minutes later you feel that something isn't right. Even though you love this album, you can't listen to it anymore. You shut it off, tired, puzzled, and confused. This always seems to happen when you switch from a classic album to a modern one. What you've just experienced is something called overcompression of the dynamic range. Welcome to the loudness war.

The loudness war, what many audiophiles refer to as an assault on music (and ears), has been an open secret of the recording industry for nearly the past two decades and has garnered more attention in recent years as CDs have pushed the limits of loudness thanks to advances in digital technology. The “war” refers to the competition among record companies to make louder and louder albums. But the loudness war could be doing more than simply pumping up the volume and angering aficionados—it could be responsible for halting technological advances in sound quality for years to come.

Overcompression

The smoking gun of the loudness war is the difference between the waveforms of songs 20 years ago and now. Here is an example:

A waveform from the late 80s / early 90s

A waveform from now

The second waveform not only has a higher amplitude than the first but is also highly compressed—there is very little difference between its highest points and the average level. In other words, the new song has a drastically reduced dynamic range—the difference between the loudest parts (the peaks) and quietest parts of the sound.

Music, like speech, is dynamic. There are quiet and loud moments that serve to accentuate each other and convey meaning by their relative levels of loudness. For instance, if someone is talking and suddenly shouts, the loudness of the shout, in addition to the content, conveys a message—be it a sense of urgency, surprise, or anger.

When the dynamic range of a song is heavily reduced for the sake of achieving loudness, the sound becomes analogous to someone constantly shouting everything he or she says. Not only is all impact lost, but the constant level of the sound is fatiguing to the ear. So why is achieving greater and greater loudness so important that the natural ebb and flow of music has been so readily sacrificed?

The answer goes back to the beginnings of recorded music.