Easy tutorial: how to normalize the volume of an audio track.

The MP3 was developed by the Moving Picture Experts Group (MPEG) to be part of the MPEG-1 standard and the newer and more widespread MPEG-2. An MP3 created using 128 kbit / s compression will be about 11 times smaller than its namesake CD. An MP3 can also be compressed using a higher or lower bit rate per second, directly resulting in lower final audio quality and the resulting file size.

Compression is based on the reduction of the irrelevant dynamic range, i.e. the inability of the auditory system to detect quantization errors under masking conditions. This standard divides the signal into frequency bands which approach the critical bands, on the basis of wp, then quantifies each sub-band according to the noise detection threshold in this band. The psychoacoustic model is a modification of that used in Scheme II and uses a method called polynomial prediction. It analyzes the audio signal and calculates the amount of noise that can be introduced as a function of the frequency, that is to say calculates the “masking amount” or the masking threshold as a function of the frequency.

The encoder uses this information to decide how best to spend the available bits. This standard proposes two psychoacoustic models of different complexity: model I is less complex than psychoacoustic model II and considerably simplifies the calculations. Studies show that the distortion generated is imperceptible to the experienced ear in an optimal environment from 192 kbps and under normal conditions. “Good” (unless you have high quality audio equipment where the lack of bass is excessively noticeable and the “fry” sound in the treble is highlighted). People experienced in the audio part of digital audio files, especially music, from 192 to 256 kbps are enough to hear well, but compression at 320 kbps is optimal for any listener. [appointment required]. Most of the music circulating on the Internet is encoded between 128 and 192 kbps, although today due to the increase in bandwidth, it is more and more common to share files with high quality. maximum compression.