Analog and Digital in Audio

There are several differences between analog and digital audio. Analog signals are convayed in several ways; electrical, mechenical, pneumatic and hydraulic signals are all types of analog signals. Electrical analog signals are the most commenly used form in audio production.

Audio Signals
Electrical analog audio signals are made up of several different factors which include voltage, frequency, current and charge. A digital audio signal is made up of a combination of ‘on’ ‘off’ signals (ie binary).

The main difference between an analog and digital signal is the continuity of it. As shown in the below image, an analog signal is a continuous signal. A digital signal, being made of a combination of ‘on’ ‘off’ characteristics, is non-continuous, as shown in the below image.

external image e_zub-3-1.gif

(http://markun.cs.shinshu-u.ac.jp/learn/osi/e_zub-3-1.gif 15/11/2010)


Audio Recording
In audio recording, an analog recording is one in which the audio is captured exactly as it is heard in the envoirnment. In digital recording, the sound is usually captured through an analog source (such as a microphone) and then converted to a digital signal. Through conversion, the analog signal is estimated into binary. Therefore, the accruarcy of a digital recording depends on the conversion capibilites of the analog-to-digital converter.

Because of these differences, a more accurate signal can be achieved in analog signaling as opposed to digital. However, these inaccuracies in digital signaling are extremely miniscule and often not noticeable to the human ear.


References
http://www.techterms.com/definition/digital
http://www.techterms.com/definition/analog
http://telecom.hellodirect.com/docs/Tutorials/AnalogVsDigital.1.051501.asp
http://stereos.about.com/od/stereoscience/a/anadigaudio.htm