What may be good for a voice podcast, is not good for music.

Ever listened to a sermon podcast in the car and got frustrated fidling with the volume control when your pastor goes from really quiet to really loud or visa versa? To deal with this problem we post-process our sermon recordings with a software compressor, effectively making the recording all one level. (Actually doing this with software [we use audacity's compressor effect] as opposed to hardware at recording time introduces it's own complications and sometimes we still don't get it right. Primarily this is because it requires investigating each recording and then applying the appropriate compression ratio's.)

However, making a recording all one volume pits listening convenience against dynamic quality. A sermon is a perfect example, because dynamic volume is a key ingredient in dynamic human speech. Communication is more than words, and volume change can expose the passion of what is being said. By listening convenience we mean the ability to hear every word while in the car or in a noisy room without turning the volume up during any parts of the recording that were originally quiet. The same levels which allowed the preacher to be heard in the church auditiorium on Sunday do not work when listening to the sermon on a podcast in the car on Monday. This is because audio sounds different in different spaces, and generally the ambient noise in a church building is quite low. In fact, some church buildings are designed that sound will carry well throughout the entire room. So for listening convenience we sacrifice a little dynamic quality. Fortunately the human voice provides other hints besides variable volume to communicate passion and intent, such as tone.

I am not a sound theorist, but would suggest that the extreme volume levelling of music (through compression) sacrifices more compositional intent than does the same practice on human speech. While each one of us is unique in the way that we hear and process sound, apparently I am not the only one to quickly fatigue while listening to certain albums. My wife sometimes doesn't understand why I all of sudden grab the volume "knob" in the car and turn down a track, skip a track, or flat out turn off the stereo. It's not like I don't like listening to music loudly, its that some loud music is so poorly engineered that I cannot separate the parts that make up what I am hearing --- it all starts sounding like loud noise that never lets up. The recording industry has been using some the same tools that allow every word of a speech to be heard (dynamic range compression) to force their music to be louder, and audiophiles are crying out about the richness of the music that is being thrown away with the bits. Part of this is justifiable, considering that the "space" and equipment used to listen to music has changed (cheap headphones on iPods, poor computer speakers, even inexpensive home theatre surround sound systems). To complicate matters, though the topic should be argued distinctly from compression, lossy audio encoding methods rule the day (mp3, aac etc.) and are starting to effect the way audio is engineered before distribution.

Simply stated, "When there is no quiet there is no LOUD". For a brief video introduction to audio compression and what it has done to music, and the source for the quote above, watch the two minute video on The Loudness War. When I sat down to write this post, I thought that the easiest way to demonstrate the text equivalent of audio dynamics was through capitalization:

WHEN THERE IS NO QUIET THERE IS NO LOUD

when there is no quiet there is no LOUD

Which communicates the intention more? Writing in ALL CAPS is considered bad netiquette precisely because it is like SHOUTING ALL THE TIME. Any music director knows that if an entire choral peice is sung mezzo-forte it will alter the meaning of the peice because dynamics are important to music.

I found that I wasn't the only one to consider the overuse of compression to be akin to typing in call caps. In 2002, Rip Rowan wrote an excellent article entitled "Over the Limit" demonstrating that recorded music has gotten louder over time through the analysis of subsequent releases from favorite band Rush. Not only does he visually show the change in the wavforms of the recordings, but he uses a paragraph in ALL CAPS to prove his point that eventually readers and listeners will tune out if there are no dynamics in a peice.

Concerns regarding the Loudness War are not new to audio engineers or audiophiles, but the industry is finally taking notice. Rolling Stone magazine published a rich article, The Death of High Fidelity, which is perhaps the best starting place to understanding how and why recordings have become so loud, and what artists think about it. Hopefully producers and music labels are still listening amidst the noise of the information age.