Inc. The following article originally appeared in the September 1997 issue of Broadcast Engineering . Broadcast Engineering is published by Intertec Publishing Corporation. Reprinted by permission. This article addresses the issue of bit errors, and describes how advanced engineering can prevent them from interfering with audio transmission.
Any transmission system is vulnerable to impairments in signal quality over distance.
Noise can be introduced by electrical transients such as lightning or equipment switching on or off, crosstalk with other circuits, or just the thermal noise associated with any electrical circuit operating at a temperature above absolute zero. Once an analog signal has been converted to digital format, the situation is quite different. As long as the decoder can tell the difference between a one and a zero, the original signal can be reproduced perfectly. As a result, a significant performance difference exists between analog and digital transmission systems under noisy conditions . On a digital system, increased line noise has little effect on decoded audio quality until the noise level gets so high that it prevents the decoder from differentiating ones and zeroes.