| As this first decade of the 21st Century draws to a | | | | of sound, which is, in fact, an analog phenomenon. The |
| close, so also does the age of analog. When it comes | | | | process by which a digital signal duplicates an analog |
| to communications, analog has served humanity long | | | | quantity is called encoding, or just simply coding. |
| and well, but the old technology is being phased out by | | | | Encoding allows the digital representation of analog |
| governments and manufacturers alike, and within ten | | | | quantities - an area of infinite variability - by using a |
| years, the old analog systems will likely be a | | | | binary system that creates an on-off switch for all |
| technological footnote to history. Put simply, analog | | | | those variables (theoretically). This use of digital signals |
| equipment cannot compete with the capacity of digital | | | | gives a major improvement in noise reduction. |
| and, as a result of simple economics, it is destined to | | | | Noise affects the inherent value of a signal, whether it |
| dwindle away. Of course, analog systems made | | | | is digital or analog, but on an analog signal the noise has |
| sense when first created, for analog signals are able | | | | an impact on the value of that signal, because |
| to duplicate virtually any natural phenomena, such as | | | | increased voltage over an analog signal creates |
| sound or light, which are analog inherently because | | | | distortion. When an analog signal is recorded, it is |
| they are infinitely variable. | | | | inevitable that noise is recorded along with it. If it is then |
| With analog systems of communications, the biggest | | | | re-recorded, the original noise is indistinguishable from |
| problem has always been noise. While analog offers | | | | the original signal, and becomes, effectively, part of the |
| the infinite variability that replicates the natural state of | | | | new signal. At each recording stage, extra noise will be |
| sound or light, converting those phenomena into an | | | | introduced into the system and multiple copying of an |
| electrical signal and then back again into a sound or an | | | | analog signal ultimately results in an unacceptable loss |
| image creates "noise." The term is used because it | | | | of quality, called generation loss. |
| can literally produce noise in an audio system - the hiss | | | | When a digital signal is recorded, it too will include noise |
| or rumble that is heard in poor quality recordings. Noise | | | | picked up within the system. However, a digital signal is |
| also shows itself in the grain or "snow" that can trouble | | | | clearly identifiable, despite any noise the signal picks up. |
| a TV signal. Noise affects an electronic signal at every | | | | At the root of the digital advantage is the fact that the |
| stage of the communications process, and its effects | | | | signals in a digital system do not have to be accurate. |
| add up. | | | | A voltage only needs to be readable as a one or a |
| Although a digital signal cannot directly represent an | | | | zero to be processed. Thus, digital communications |
| analog quantity, everybody know that a digital device | | | | signals offer possibilities which have no equivalent in |
| like and Mp3 player offers excellent quality duplication | | | | analog systems. |