To answer this question, we need to break it up a bit to help you better understand what is going on. This article will explain what is sound, how it is recorded, how it is stored and how it is reproduced. It will also present key differences, benefits, and downsides between analog and digital sound.
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What is the sound?
The sound is the vibration of the medium, in most cases the air, being picked up and interpreted by our hearing. If something is vibrating, it means creating the waves, in this case, the sound waves. And every wave is defined by the frequency and amplitude. Most humans can hear the sound frequencies between 20 Hz and 20 000 Hz, or 20 kHz.
Figuring out the sound’s nature was a first, necessary step towards finding out how to record, store and reproduce it. It all began in the 19th century and the Industrial era. One of the most distinguished pioneers in this area is world known scientist, industrialist and entrepreneur, Thomas Edison. His Phonograph, invented in 1877, pawed the way for further development and mass production of sound recording and reproducing equipment.
Keep in mind that there is no fully digital sound. “Digital” refers to the way sound is being stored and distributed. In any case, digital recording needs to be converted back to analog to be produced. But, more on that subject later in the article.
Analog sound recording
There were three major technology leaps regarding analog sound recording. The first method of sound recording was purely mechanical. This period is also known as the Acoustic era, and it lasted between 1977 -1925. During this period, the sound was being channelled by a large cone towards the diaphragm at the narrow end. That diaphragm would then vibrate and transfer those vibrations to the articulated scriber, stylus or needle. This needle would then leave the imprints of those vibrations on a soft, rotating surface of the recording medium. This medium was usually a wax-covered cylinder. But this was somewhat a tricky business, and it recorded a quite limited frequency range. Most devices couldn’t record more than 250-2,500 Hz range. The device wouldn’t record Anything above and below that, and sound would be lost.
Further developments in science and technology lead to the Electrical era (1925-1945). Significant leaps in electrics and electronics made it possible to capture, filter and amplify sound electronically before using a mechanical process to engrave the sound on to the master record. Turntables and vinyl records we use today are the products of this era. Recording allowed capturing, storing and reproducing the sound with more fidelity, but still only 60-6,000 Hz range. So, there was still a lot to be desired regarding the entire frequency range of our hearing.
The last step towards analog recording we sometimes use to this date happened just after World War Two. Germany has developed a way to record sound on magnetic tape in the 1930s. This technology became available to the western world after the war, where it got further developed.
In essence, this technology allows recording with exceptional fidelity. Sound is captured by the microphone and turned into an electrical current. This electric current charges a magnet touching the passing tape, thus charging the particles on the tape. This kind of imprint was able to store a much wider frequency range than ever before, and it soon became a standard all over the world. Further developments allowed multiple tracks of sound to be recorded on the same tape. That is where we are at this date in regards to analog recording.
Technology moved forward, and that took us into the digital era.
Digital sound recording
The development and availability of computer technology was a prerequisite for digital sound. The critical difference is that, in digital, you need to convert those sound waves into a series of 1s and 0s to store them. So, how do you do that?
Just as in analog sound recording, a signal is being picked up by the microphone. But then it needs to be “digitalized”. The standard method to do this is called PCM. It stands for Pulse Code Modulation. It works by creating a sound wave model as a series of ones and zeroes by recording values at specific points along the wave and turning them into binary code. These groups of binary bits are called samples, and an analog-to-digital converter does this process. To playback the music, the digital-to-analog converter reverses this process. Then the electric signal goes to the amplifier and the speakers.
The sound’s quality is determined by the number of bits used to store information for each point and how many times per second it is recorded.
CD-quality standard uses 16 bits to record each sound wave’s value and does it 44,100 times per second. Professional recording equipment uses 24 bits at, up to more than 96 kHz.
This kind of sound recording offers good quality but presents a new problem – file size. A couple of minutes of recording at top quality would take up tens, if not hundreds of megabytes of storage space. And that is not very practical on the larger scale. This issue is being addressed by using one of many compression standards. One of the most popular ones we use today is MP3. It allows a significant reduction in space the file takes while retaining good enough quality for most users.
Critical differences between analog and digital sound
Ever since digital audio became a thing, there is an ongoing debate which is better- analog or digital? Here are some key aspects and differences between the two.
Ease of use
To record, distribute and reproduce analog sound, you need many different devices and media. It is much more expensive and takes much more space than digital. If you, for example, want to send ten analog copies of a song, you need a tape recorder and ten blank tapes. All you need to do with digital is copy/paste one file ten times or send it to different e-mail addresses. To record one hundred songs, you need miles of tape. At the same time, they can all easily fit on a small memory chip.
Quality
This is a tricky part. On the one hand, analog audio can record and reproduce a much wider range of frequency and more precise than digital. On the other hand, digital audio sound has second to none noise embedded into sound.
One other aspect is latency. Since digital audio needs to be converted from analog to digital and back, this unavoidably creates some latency in reproduction. This latency can, in some cases, be confusing and create problems if the musician is, for instance, trying to listen to himself playing on his monitor
Durability and vulnerability
When you record the sound on some modern digital media, recording will be much better protected than it could be using any analog. Magnetic tapes can easily be damaged if they come into contact with any magnet. Vinyl records can be scratched, and the sound’s quality deteriorates each time you play it from the media. Digital storage is far more durable and long-lasting in this regard, making it a better storage option for a more extended time period.
SUMMARY
Analog audio sound began its life in the nineteenth century, progressing with quality over time. It has been overtaken by digital audio at the end of the twentieth century.
“Digital” refers to the way audio is stored. It still needs to be converted from an analog recording microphone and then turned back to an analog signal and sent to the speakers.
Analog audio is being recorded by transforming the electric current into the magnetic imprints on the magnetic tape.
Digital audio uses bits to record different values of the sound wave multiple times in a second.
Analog audio sound has a much broader frequency range. It records and reproduces sound much more accurately but suffers from electric noise issues.
Digital audio has virtually no noise in the recording.
Analog audio media is much more bulky, expensive, harder to produce, maintain and distribute
Digital audio files are easy to store, maintain and distribute, but inefficient in best quality.
In the end, both analog and digital have their place and use in our world, and it all comes down to personal preferences.
