Dr JM Pisano gives us a great article on audio compression which is used to add dynamic range to an audio signal. The four basis knobs on your everyday compressor are Attack, release and ratio which are explained in detail.

Common use examples for compression are shown here from: using compression on a bass guitar so that the sound does not “walk” over top of other instruments, application on studio and live vocals to clean up the signal and compressing the overal stereo mix to “reduce the peaks” recorded or during the mastering phase.

[MusTech.Net!]