During the mid '90s, a team of students at MIT undertook an experiment to see whether the quality of a TV signal's audio track could impact the perceived quality of the video track. Participants sitting at a monitor were told to indicate when the picture quality began to degrade. Time after time, the response was the same: When the testers degraded the audio signal, the subjects would indicate that the video was getting worse. In fact, the video signal remained the same.
The story of that test is an oft-told tale by audio engineers because it's such a powerful example of a simple truth: TV is defined by video, but audio can make or break a telecast. Nothing chases away viewers faster than consistent audio miscues.
Today's broadcast environment, however, makes it more difficult than ever to remain glitch-free. Surround sound delivering 5.1 channels of audio (the five refers to the front left, center, and right speakers and the left and right rear speakers; the .1 delivers low-end bass signals to a subwoofer) is becoming more popular with broadcasters. Delivering those signals to viewers requires new gear and new techniques. And cable operators increasingly deliver 5.1 surround sound, particularly for their pay-TV movie services like HBO or Showtime.
But new technology for its own sake is never a reason for broadcasters to implement new systems. The important thing is to serve viewer demand, and, increasingly, that's the case with surround sound.
On the viewer end, more and more homes are equipped with large-screen TVs, which demand a large-screen audio experience. That requires a robust audio system, the same one viewers use to listen to music. The days of their listening to TV audio through a small mono speaker on the TV are long gone. In the marketplace, consumers just won't hear it.