The Loudness War Is Real, and We Can Prove It With Science

September 25, 2013

Welcome to the fourth installment of our investigation into audio trends. To figure this stuff out, The Echo Nest data alchemist Glenn McDonald ran the 5,000 hottest songs from each year through The Echo Nest’s system for listening to music to determine its audio attributes (we also do lots of other stuff, but that’s one thing we do). Previously, we looked into how music’s “danceability,” energy level, and tempo have changed. This one concerns loudness.

"Hey, kids, turn it down!" It’s been a popular refrain for decades. As it turns out, there’s something to it.

We might more accurately aim that request towards the producers and recording engineers who have packed more and more loudness into popular music, over the course of several decades.

The thing is, they aren’t doing all that loud-making in a vacuum (physical or cultural). The audio wizards have been responding to what they think artists and listeners want — and what we want, apparently, is ever-louder music. A bit of extra heat and compression can make songs “pop” a bit more when they come out of your speakers or headphones when juxtaposed with quieter fare. In that sense, we’ve all had a hand in music getting louder over the years — a phenomenon commonly known as “the loudness war.”

We have the data, and it tells a fairly clear picture about loudness over time. The loudness of the hotttest 5,000 songs each year increased very slowly from the ’50s through the ’80s, and then more rapidly and steadily, all the way to the present day:

It’s worth defining what we’re talking about here, because loudness is a tricky concept. Whether you’re dealing with analog formats (records and cassettes) or digital formats (compact discs, downloads, and streams), there’s always a maximum volume at which a song can play.

But wait — how is music getting louder, then, if there’s a volume limit?

The answer: by compressing softer and louder sounds within each song into a smaller area — basically, amping up the softest instances to make them closer to the loudest instances — and then cramming that narrower band of loudness right up against the maximum a particular format can take. Although it reduces dynamic range (the distance between the loudest and softest sound you hear on a given recording), the overall effect is to create a perception that the song is louder.

As our chart shows, “the loudness war,” in which music-makers compete to sound the loudest, is real. Critics of the trend complain that listening to a bunch of super-loud, dynamically compressed music in a row can lead to hearing fatigue, and that compressing the instant-by-instant volume variations of music into such a flat, tight band erodes music’s complexity and subtlety.

Meanwhile, other people just like their music louder — the more average decibels, the better.

One thing is clear: Popular music started getting louder during the heyday of Elvis Presley, Buddy Holly, and The Everly Brothers, but only by a little bit. Right around the rise of the compact disc, in the very late ’80s, music started getting louder at a faster rate. The trend continues to this day.

See previous installments of our “audio trends over time” analysis:

Stay tuned for our continued research into audio trends over time.