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Written by: James Bunning
Written on: December 7th, 2016
Tags: lifestyle, computer engineering, music, sound engineering
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About the Author
James Bunning was a student at the University of Southern California at the time this article was written.
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Volume XVIII Issue II > The Battle of Sound

Why Digital Audio Escalated the Loudness Wars

Similar to the way the machine gun in World War I completely changed the landscape of how wars were fought, the added firepower of the compact disc (CD) and digital audio processing in the 1980s escalated the loudness wars to new, ear-splitting levels. When first introduced, the CD recording format let music producers make recordings louder than vinyl recordings because digital audio overcame the physical limitations of vinyl records, such as needles jumping out of grooves [3]. Digital audio gave sound engineers the technical freedom to record music regardless of the peak loudness of the incoming audio signal [4].
While CDs did not place the same physical limitations on peak levels, the format did have a definitive loudness level over which the digital audio signal could not be boosted without clipping and losing information. This level is known as 0 dBFS, or “full scale.” If 0 dBFS were a card in the game Monopoly, it would likely read: “Do Not Pass Go, Do Not Collect $200.” Music producers began recording CDs far below this level, but the loudness wars picked up again towards the end of the 1980s as multi-disc CD changers started to gain popularity; record companies wanted their CDs to stand out from their competitors’ [3]. By the early 1990s, music producers were elevating the peaks of digitally recorded songs to the point where peak levels started to push the loudness limit of 0 dBFS. Once music producers reached this point of no return, the only way to raise the average level of the audio was to compress the peaks. Yet, unlike analog compressors, which were restricted by how much they could reduce the peak levels of tracks, digital compressors were much more powerful [3]. Sound engineers quickly began hyper-compressing audio in order to squeeze in as much loudness as possible, pushing the average level of songs up to as high as -6dBFS through the 1990s and 2000s [3].

Does Hyper-Compression Hurt Sound Quality?

In-and-of-itself, compression does not diminish audio quality. In fact, music producers often use compression as a creative tool in recorded music. Sound engineers use hyper-compression in a variety of creative ways other than simply increasing loudness, such as shaping the sounds of instruments and helping them stand out from others in a mix [4]. In hip hop, R&B, and dance music, music producers purposefully clip percussion by pushing it over the 0 dBFS point of no return as an aesthetic choice to get the driving “boom-bap” sound behind their beats [5].
However, audiophiles, casual music listeners, and even many music producers have argued that hyper-compression of the loudness wars have degraded the sound quality of modern recordings. Their chief complaint is that, by squashing the dynamic range of audio tracks through hyper-compressing, many modern music recordings sound flat, lifeless, and unexciting [6]. As prominent music producer Bob Katz put it, “You want music that breathes. If the music has stopped breathing, and it's a continuous wall of sound, that will be fatiguing. If you listen to it loudly as well, it will potentially damage your ears before the older music did because the older music had room to breathe” [3].
One famous backlash against the loudness wars occurred in 2008, when the band Metallica released two versions of its album Death Magnetic: one for the video game Guitar Hero and another as an audio CD. The CD version of the album was hyper-compressed and significantly louder than the Guitar Hero version, and as a result over 20,000 fans signed an online petition asking the band to re-master the CD [6]. Waveform analysis of "My Apocalypse" from the audio CD demonstrates the lack of dynamics, which were sucked out of the song as a result of audio compression (Fig. 4). In fact, the recording has an even smaller dynamic range than the song “Down Where the Big Bananas Grow,” primitively recorded in 1909 with an Edison cylinder.
https://illumin.usc.​edu/https://illumin.​usc.edu
Figure 4: Waveform A: "Down Where the Big Bananas Grow" (1909 Edison Cylinder); Waveform B: "My Apocalypse (Metallica, Death Magnetic, 2008).

Are the Loudness Wars Here to Stay?

Although music producers continue to hyper-compress tracks in order to increase the loudness of digital music recordings, the end of the loudness wars may be near due to the growing popularity of Internet music streaming services such as Spotify and Apple Music. Both Spotify and Apple Music use a loudness normalization algorithm that maintains a consistent loudness amongst all songs played back in shuffle or playlist modes [4]. By normalizing all tracks to the same level, streaming services take away the advantage of producing loud CDs or other digital audio downloads from music producers because all songs sound equally loud. In fact, when compared to less-compressed tracks, the hyper-compressed songs sound dull, weak and somewhat muffled, which may encourage sound engineers to started producing more dynamic music.

Conclusion

Even if Spotify’s and Apple Music’s loudness normalization trend catches on, the loudness wars may still be far from over. Hyper-compressed, louder-sounding music often suits the way modern listeners listen to music– on-the-go, via iPods and other portable music players. Louder sounding music blocks out the ambient noise of cars, public transportation, waiting rooms, and coworkers, which can interrupt quieter songs. Furthermore, after 20 years of listening to hyper-compressed tracks, many listeners, the youngest in particular, are simply accustomed to loud recordings and do not know the difference. Only time will tell if a peaceful end to the loudness wars is on the horizon.

References

    • [1] C. Clark. “The Loudness Wars: Why Music Sounds Worse.” NPR: All Things Considered, December 2009.
    • [2] E. Deruty. “Dynamic Range & The Loudness War.” Sound on Sound, September 2011.
    • [3] S. Sreedhar. “The Future of Music: Tearing Down the Wall of Noise.” IEEE Spectrum: Technology, Engineering, and Science News, May, 2007.
    • [4] H. Robjohns. “The End of The Loudness War?” Sound on Sound, February, 2014
    • [5] G. Milner. Perfecting sound forever: An aural history of recorded music. New York: Faber and Faber, 2009.
    • [6] E. Vickers. “The Loudness War: Background, Speculation and Recommendations.” AES 2010: Paper Sessions: Loudness and Dynamics. San Francisco: Audio Engineering Society, July 14, 2011.