Volume equalizer, how does it work?
Many people ask us how an mp3, mp4, etc. They save so much space.
/stickers-abstract-music-volume-equalizer-concept-idea-background.jpg.jpg)
First of all there is obviously the zip type compression. That is, those algorithms that reduce the space basically seeking to eliminate the redundancy of symbols. That is, if in a row you find: 11111110000000 what you do is put 7-1,7-0 implying that there are 7 times a one and 7 times a zero. You save space by describing what you write when you have repetitive characters.
This is just a very simplified example.
But there is also another compression that is based on knowing how the human ear works. We already know that there are low and high frequencies that the human ear does not perceive, so everything that is outside the hearing range of the human ear can be ruled out.
There is also masking, which implies that if two similar frequencies sound almost simultaneously, one of them at a higher volume, it will mask the second, that is, we will not hear the second, so it can be discarded.
It is obvious that all these processes cause information to be discarded and that can damage the quality, but in general, if it is done correctly, the human ear, even the trained one, cannot perceive the difference.
Thousands of tests have been done making people, including musicians, listen to high bitrate mp3s and listen to a WAV and it has been verified that they cannot tell the difference.
/GettyImages-123523274-5730d0af3df78c038e696b71-dcaf2129c5d64a349868ec4cbb24fab3.jpg)
