How Analog and Digital Recording Works

Thomas Edison did the first sound recording in 1877 with the help of a moving needle attached to a vibrating diaphragm in response to sound. With time, the technology involved in sound recording has advanced immensely and it is possible to capture even the minute sounds originating in faraway places such as different planets in the solar system. However, from its early beginnings, there are only two distinct recording mechanisms to capture sound and these two methods became popularly known as ‘analog’ recording and ‘digital’ recording.

Out of the two recording mechanisms, ‘analog’ recording was the first to be discovered and although it has been replaced by newer digital recording in most instances, it remains a resilient technology that has its own unique uses. ‘Digital’ recording on the other hand is the popular choice in the modern digital era and understanding how these two mechanisms work will enable a person to realize the differences between the two methods.

In both methods, the sound capturing devices would function in the same way and it is the sound waves, which will be converted to electrical signals inside the microphone device. Once electrical signals are generated using the air pressure waves generated with sound, it can be stored using one of the above mentioned methods.

In analog recording, the electrical signal generated would be analogues to the air pressure variations taking place when sound travels through air. A tape or a cutter device will enable imprinting or cutting the same variation or pattern in the recording media, which can later be read using a similar device.  Some of the examples for analog recording devices include, the magnetic tape device and the grooves of the gramophone disk.

During digital recording, a device known as a ‘digitizer’ or a analog to digital converter will create a sequence of electrical signals in the form of ‘1’s and ‘0’s. This enables the recorder to store the sound as a discrete set of numbers instead of a continuous pattern in the recording media. When it is necessary to playback the recording, the digital information will again be converted into analog signals using a digital to analog converter. Almost all the recording devices presently used belongs to this category and some of the common digital media include, CD, diskettes and other electronic storage medias.

Although both techniques can generate high quality sound when the right equipment is used at the right time, there are several discrete differences between the two recording methods. The digital recording will be able to achieve uniform source fidelity while the cost of recording and duplicate would be low. At the same time, a digital signal can be used by all the modern day portable recording devices. Analog recording on the other hand would require bulky and high quality play back devices in order to achieve the same outcome. Apart from these, the facility to error correct and therefore ensuring the accuracy of the signal, ability to replicate the same digital signal infinitely without losing its quality and the ability to edit digital recordings using a computer far efficiently than its analog counterparts are some of the other advantages of digital recordings in comparison to analog recordings.


Practical Recording Techniques: The Step-by-step Approach to Professional Audio Recording – (Bruce Bartlett, Jenny Bartlett)