MP3 Explained - All About MP3 Music, Files, Downloads and Digital Music

One of the ways in which MP3 saves so much space, is to strip away information that we, as
humans, cannot hear. The human ear is only capable of hearing (or more importantly,
discerning), sounds within a certain frequency range. The MP3 algorithm, strips away the
frequencies outside this range, as most people will not hear them anyway.

Another way MP3 removes information, is that in a stereo song, much of the information is
duplicated on each channel. The algorithm will remove much of that redundant data.

Digital music is composed of numbers representing the analog audio waveform. When we look
at an audio CD, we find that it uses quite a bit of space. When we initially rip this data to our
computer, we are bringing in an exact copy of that data. This translates to a huge waste of
space on our hard drives, portable audio player, iPod, etc.

An MP3 encoding algorithm, as well as other digital compression techniques, uses
psychoacoustics to figure out which parts of the sound it doesn't need to save, without us
knowing it is gone. It will analyze the digital audio data, trying to map it to the limitations of our
ears, and how our brain discerns those sounds.

Some people have better hearing, or discerning abilities when it comes to music, but for the
most part, MP3 encoding will satisfy the masses, as evidenced by the billions of MP3s floating
around the world. It seems like almost everybody has an iPod these days, or some sort of
portable music player that will play MP3s. Also, almost everyone has a computer these days, so
MP3 songs are obviously good enough for most everybodies tastes.

Read our section on bitrates, to see how they effect the way the resulting MP3 encoded music
sounds to the listener.