A compressor, either hardware or software, is used to to do produce this compression.
This means that the difference between the loud parts and the quiet parts of a track or audio signal is reduced. The way we are using the term “compression” here relates to dynamic range reduction. Other effects, like reverb, delay and chorus make an obvious difference to the sound, but with compression it can be harder to hear what’s going on.
It’s also one of the hardest to understand properly. Compression is one of the most commonly used effects in music production.
