Attack of the Pod Penguins: Normalization
- — 06 December, 2006 12:35
Whether you're interested in a music-format podcast, or one that's primarily spoken-word, you'll inevitably run into some vexing issues. The issues always seem to stem from the nature of audio recording and how the raw files at your fingertips, awaiting editing and post-production, can sound so different from what you expect to hear in a final format.
Despite great effort to record files of a consistent quality and sound, there's always a gap between expectations and reality. The problem is the transfer of the sound from a natural holistic medium -- sound waves in the air captured by the ear and interpreted by the brain -- to one in which software and hardware are an integral part. There's something about computers that squeezes the natural life out of audio files. Honestly, the same could be said of magnetic tape in the days of reel-to-reel recording, or of cassettes in their heyday. The act of capturing audio in any mechanical or electronic format tends to suck the natural feel right out.
So the primary challenge in processing digital audio files is fundamentally the same as it's been in any analog medium. It's the problem of recording a natural sound in a way that only minimally intrudes on the natural qualities, then processing that sound in a way that doesn't sound processed. When put that way, it seems like a bit of a conundrum. But, take heart. It's a conundrum that's been attacked and, to a large extent, solved by the hundred-year-plus history of capturing audio. Some great minds have spent time analyzing the problem and have created and applied solutions -- solutions that are available to all.
There's another issue that's particularly applicable to podcasting. It's the revolutionary attitude toward podcasting as citizen media -- the Holy Grail in the break from institutional information. It's the idea that media belongs in the hands of citizens. I couldn't agree more wholeheartedly with the premise. But, there's still some difficulty in defining the qualities of that citizen media. Purists would, in many ways, be willing to throw out the baby with the bathwater to achieve a complete break from the mainstream media we've all grown up with. In advocating a radical departure in content, mainstream media as a whole is painted with a broad brush. Podcasting purists -- those who most vociferously advocate a complete break from corporate media -- seem willing to toss out the sound of mainstream media, as well. Forget the contrived formats. Forget the self-obsessed radio personalities. Forget the in-your-face and largely irrelevant pursuit of commerce in the form of advertising. Everyone agrees that those elements of media can go away with little real loss. But, to some, media doesn't really become citizen media until its physical sound is also radically different.
My premise is proven over and over in thousands of podcasts for which attention to sound quality seems to be a shunned element of the old media. To some, a podcast has to sound unrehearsed, natural and, in many cases, uneven, in order to represent a complete break. In a subtle confusion between content and audio quality, podcasters often seem far too willing to toss aside the careful attention to capturing and processing sound. The revolutionary says, "Podcasting shouldn't sound like radio." In terms of content, I'm with the revolutionaries.
But the sound of radio is really, subtly, what we expect, even in a podcast. For all the shortcomings of radio related to content and consumerism, the audio engineers who have brought us to this point in the sound of radio have done very well. We expect a certain level of sound quality -- a level established by radio, even in podcasts. That's because, in large part, radio has solved the conundrum noted above -- recording natural audio in a non-intrusive way and processing it in a way that doesn't sound processed. And, if it does sound a touch processed, we understand it's radio.
Which brings us back to the original and most fundamental premise of this series of stories: that creating a podcast in Linux makes great use of the "one tool, one job well" philosophy of open source. While you'll certainly need a framing hammer like Audacity in building your podcast, you'll also need a level, a plumb bob and a tape measure. Those tools exist in abundance for Linux and other free and open source software platforms. In short, there's really no reason why your podcast can't be delivered with the high quality audio most listeners expect, whether or not they realize it's expected. Individual command-line tools exist to solve all the problems inherent in the audio capture conundrum. For the most part, they offer all the flexibility and control you'd expect from command-line tools and are, with a bit of investigation, very easy to use.
The first of these tools is one best explained by first stating the problem it's intended to solve. Regardless of the type of podcast you choose to produce, it's likely that you'll have more than a single file to edit and include in the show. And, it's unlikely that you'll be able to control these files from start to finish. You may choose to include musical transitions in a spoken-word podcast. Or, to improve overall quality, you may have participants in a roundtable format record and submit their parts of a Skype call locally. Even in cases where you control the process start to finish, you'll likely still find that some elements of the audio are quieter than others. As you've seen with Audacity, you can choose to amplify those sections or files by hand. But, that's a terribly inefficient and time-consuming process. And, it's unlikely that you'll be able to make those adjustments seamlessly.