Sound Advice: Bits and Bytes

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Long ago, in a studio far, far away, audio engineers labored with fragile plastic ribbons covered with a mysterious rust-colored substance. Their task: to coax audio recordings onto and off of reels filled with these ribbons. While there was a great deal of science involved, a generous dose of black magic was required to achieve a quality recording. Not to mention the time and money required archiving these delicate recordings for future generations.

Today, things are much easier. Video producers have the ability to record near-perfect performances all day with just the click of a mouse. Editing is easy and mistakes are just an undo away. Archiving with optical discs is the norm and the digital media revolution makes it both possible and practical to keep multiple copies of our work scattered all over the globe. Unfortunately, with all this ease-of-use comes confusion about the process of recording and processing digital audio. In this month's Sound Advice, we'll take a closer look at all those ones and zeros.

History and Math
Back in the late 1920s, a man named Harry Nyquist developed a theorem that describes how to accurately convert an analog signal into a data stream. While the theoretical framework could easily fill this space on its own, the basic equation is pretty simple. To recreate our signal correctly, Nyquist said, we must take a sample of the audio with a period that is at least twice the frequency (pitch) of the audio. Wait. Sample? Frequency? What does that a…