apulSoft released apUnmask, an audio plugin to amplify components of the audio that are psychoacoustically masked by other components.
To achieve this, apUnmask uses parts of the detector algorithm of the opus high-quality audio compression codec. Signal components that would get removed by compression are extracted. These can normally not be heard as they are masked by louder components in time and frequency. apUnmask enables amplifying and sculpting the masked content and adding it to the music.
To shape the frequencies of the extracted signal, it is fed through a linear phase graphical equalizer. It features a bezier curve smoothed frequency response without overshoot.
The result is a form of hyperrealistic audio. The process helps the listener to hear more aspects of the music at the same time. apUnmask can be used as a mastering effect or as an intelligent exciter for single instruments.
More info here: apulSoft | apUnmask