Akai MPC TOUCH User Manual page 174

Silence
This process replaces the region between the start point and end
point with silence.
Extract
This process deletes the regions before the start point and after
the end point and saves it as a new sample (with a name you
enter) in your current project.
Tip: This is useful if you recorded a drum loop and wanted to
remove just a snare drum hit, a kick drum hit, etc. to use
separately in the project.
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