Differences and advantages. How to digitize an audio.
The transition from analog to digital audio has been the most significant evolution in the world of professional sound throughout its history. This change has completely transformed the way of working, listening and storing the audio. We stop using cassettes to record on hard drives. We stop editing with scissors to do it with software. And also, we will stop listening to radio and television in an analog way to become, in a few years, a digital audience.
But we go in parts, because we talk a lot about analog and digital sound, but we still don’t know how they differ.
Analog Audio
Analog means the same, similar. When recording in this format, we make electrical copies of the original sound that can then be read by a device. For example, the electricity generated by a microphone when it receives sound vibrations is capable of moving a needle and creating a groove in a disk. Then, that same needle can read the groove and the vibrations generated by the movement of the needle become an electrical value that is transformed with a speaker into the same sound we recorded. (1)
The same happens in cassette tapes. Through magnetism we save the sounds converted into electricity that can then be converted back into sounds. Both the tape and the vinyl record are analog recording media.
Digital Audio
A compact disc or flash memory are digital media. This type of audio does not make copies of anything, it only transforms the vibrations into 0 and 1, the two digits that make up the binary system, the language of computers and digital equipment.
ADVANTAGES OF DIGITAL AUDIO
Less storage space
Saving thousands of minutes of audio in analog formats means towers and towers of cassettes or entire discos full of vinyl. All that fits now on a hard drive.
Thousands of copies with the same quality
Digital audio is multigeneration. It allows you to make hundreds of copies of the same original, or copies of copies, with minimal loss of quality.
Does not deteriorate
The audio that we store in similar formats, for reasons of humidity or temperature changes, eventually deteriorates over time, while saving digitally can last centuries.
Faster access to information
In the cassette tapes we had to rewind and it took a long time to find the desired fragment (linear access). With the right digital audio and software, it is much faster (random access).
Comfort in editing
To edit an analog audio, such as an open reel tape, you have to cut with scissors and then paste it. With digital systems everything is more comfortable and simple since we work from the computer with sequences of zeros and ones.
DIGITALIZE AN AUDIO
Digitize
A microphone transforms a sound wave into electricity. It is what we call an analog audio. This electricity can be encoded and saved in 1 and 0, becoming a digital audio. This encoding is done by the audio card. Then, the sound in zeros and ones, we work on the computer, editing it, adding effects … The last step is to transform those binary digits (0 and 1) again into electricity and, with the help of a speaker, again into sounds. (2)
Digital Audio
In the figure we can see how the analog wave is encoded in ones and zeros and decoded to become an analog wave again. Ideally, the final wave should be as close as possible to the initial wave. That will mean that the digitized audio has good quality. The process to pass analog electricity to binary digits has two steps.
Sampling
In the paint notebooks we scratched as children, there were drawings that were made by joining numbered dots. From point 1 to 2 you drew a line, from 2 to 3 another and so on, until the drawing was taking shape. In the end, you could contemplate the silhouette of the genie of Aladdin’s lamp.
If there were few points, it was difficult to outline the details, especially the curves, and the drawing did not look very good. However, if there were many points and they were quite together, the form was more precise and the genius more real, you could almost ask him a wish. That is exactly what happens with digital audio.
It can be of poor quality, if there are few “points2 or samples per second or it can be of very high quality with many sdamples per second.
