What is the advantage over MP3?
In the same title encoded in two formats, MP3 does not allow you to listen to sounds higher than 18 kHz
In the last ten years, the MP3 format has established itself as the preferred format for listening to dematerialized music. While it has come a long way, especially with compression rates that have gone from 96 kbps to 192, or even 320 kbps, it is a corrupt format.
In fact, the MP3 format is a lossy compression format, meaning that the sounds produced are not faithful to the initial recording. Therefore, some sounds disappear directly from the recording. For example, MP3 files cannot hear high-pitched sounds at a frequency higher than 16 kHz, while the human ear can hear up to 20 kHz.
Lexicon:
Bits: 16 to 32 for a lossless file, this is the amount of information present in a given sample. The higher the number, the more information is important and the more accurate the sound quality. The number of bits is used to set the dynamics of the recording sound.
kHz: This is the unit used to measure the sampling frequency. This frequency, associated with the number of bits, makes it possible to know how many times this number of bits is found in one second. Therefore, a 16-bit / 44.1 kHz CD-quality file will contain 705,600 bits in one second per channel, or a 1411-kbps quality file for a stereo file.
Audio compression: MP3, like WMA or AAC, is a compressed audio file. Specifically, this means that the file has been corrupted compared to the CD file to make it lighter and easier to transport. A lossy compressed file will have flatter sound levels, very high or very low sounds that disappear, and even compression artifacts that make some sounds disappear.
In audio formats, compression results in lighter files that are convenient to download quickly, but sometimes of lower quality. The lower the number displayed, the worse the quality. Therefore, an uncompressed or lossless compressed audio format will have more depth, will be less uniform between the weakest and strongest notes. Then an MP3 file compressed to 320 kbps will be of higher quality than an MP3 file compressed to 96 kbps. We can make an analogy between an audio file and a video file. Like video, a compressed audio file will be of lower quality, with less clear picture or sound and more or less visible or audible compression artifacts, but less weight than an HD file. This is the main difference between traditional audio formats and those that are compressed without loss, then called “lossless”.
What are the differences between CD and HD audio?
The human ear can hear perfectly up to the quality of coding in CD, that is to say in 16 Bits at 44.1 kHz. At a higher sample rate, it is much more difficult to detect quality differences between two identical sounds encoded at different frequencies. The Nyquist-Shannon sampling theorem indicates that it is particularly difficult to detect sounds at a sampling frequency greater than 40 kHz.
However, some people may listen to titles encoded at a higher frequency. This is the very principle of HD audio. These are titles encoded with a higher frequency and number of bits than the CD. Then we get closer to the audio quality of the master of an album, that is to say its most perfect studio version, directly from the studio recording, which can go up to 32 Bits at 192 kHz. There are many formats, physical or dematerialized, that allow you to listen to files in HD audio quality. Also, more and more services are beginning to differentiate themselves from MP3 and offer CD-quality files in a dematerialized version, allowing you to get the most out of an album as originally planned.
The reality, as studies have shown, is that people DO NOT distinguish between a normal CD and an HD one.
Many tests have been carried out and it has been shown that the common people, even musicians, do not distinguish one from the other.
So it seems more like marketing, rather than an audible reality.
