The threshold of hearing and decibels in an mp3
Very often people talk about the term normalize the volume of music.
But there are several concepts that we must be fairly clear to understand which program works best to achieve this standardization and even to know how to take advantage of the program.
We as creators of the mp4gain have had to delve deeply into the fields of acoustics as well as psychoacoustics and with terms that people are not entirely clear about how decibels are.
In other words, it is perfectly normal for the common user to wish that all their audio or video files have a similar volume and an even volume gain level, that they have a similar loudness so that they do not give the impression that the volume increases. and go down with each video or with each song.
We consider it important to provide a brief explanation of the decibel term to clarify some concepts and to help them better understand which program works best and how to get more out of that program, which for us is mp4gain.
The threshold of hearing
We call the intensity threshold of hearing what a sound needs to have to be captured by the human ear.
It is important to be clear that the threshold is not the same for all frequencies. What the human ear can perceive. And this is a point where it stands out clearly in Mp4gain, because in its algorithm we have taken into account that different frequencies have different thresholds. Therefore they must be treated differently. Since the lowest sounds have a higher threshold unlike the higher frequencies columbar is normally 0 decibels.
With the above understood, it will be understood why the idea of simply measuring the peaks of a song and then increasing the volume of the entire song As much as possible so as not to saturate those volume peaks, is a very primitive concept that gives very bad results .
Normalizing the volume of a song or video is something really much more complex, which has to be done by frequency widths and taking into account many other points such as the masking used by some formats such as MP3.
All this explanation seeks that the user understands what to solve the problem that he has, What is basically that he wants to match the volume levels of his different audio or video files, to the needed increasingly refined algorithms to achieve truly important results.
Also the mp4gain offers another series of functionalities such as modifying the Pitch of a song Without modifying its speed or vice versa
