You’ve probably heard about compressing music from a CD to save the data onto PC, or about purchasing compressed music files over the Internet.
What is this “compressing music” all about?
Here, we take a look at exactly what happens when we compress audio (music, etc.).

A CD player lines up 44,100 pieces of data per second in order to reproduce sound waves (this is referred to as a sampling rate of 44.1kHz).  It would be possible to simply reduce the number of pieces of data by half in order to halve the data size, but this would also reduce the sound quality.

Audio compression technology considers human auditory characteristics, and uses a variety of digital signal processing technologies to enable data size to be reduced with almost no loss of sound quality.

So, what is this information that we are able to discard when we compress audio? Basically, sounds that are difficult for humans to hear.  Audio compression technologies are able to reduce data size either by simply not recording these sounds, transforming them into other sounds, or eliminating them.