Sound Reasoning: Working with Acoustics

Many videomakers, even serious beginners, will take a lot of time to properly place their lighting equipment for the best possible look. They'll use scrims and flags and all manner of lighting products to eliminate or create even the slightest of shadows. And then, once the tape starts rolling, they'll stick a microphone in the scene seemingly without concern for the quality of audio they're recording.

Perhaps this is because so few videomakers understand acoustics, which is the nature (and study) of how sound moves. Like light, sound moves and bounces around the room where you're shooting. If you understand how sound behaves in the various spaces and places you shoot video, you'll be able to control it nearly as well as you control your images.

Room Tones
Every room or enclosed space has a different effect on sound, sometimes called an "acoustic signature." Sound travels in waves, almost like ripples on a pond. Lower bass frequencies have longer waves (greater time and/or distance between peaks) and higher treble frequencies have shorter waves. When you make sound, the waves actually bounce around and reflect off of a room's surfaces for a time before they decay. Every time a sound wave bounces it gets both partially absorbed and scattered in different …