A process is used when music is compressed into MP3 to discard all the sounds a machine thinks the human ear can't audibly perceive, thus vastly reducing the amount of storage needed to hold entire albums.

The problem with this form of 'lossy' compression is that many people can perceive the bits of audio discarded and are left with the feeling that they're listening to lower quality music. This is where the term 'bit rate' comes into play -- the lower the bit rate, the more data that's been thrown away and, therefore, the lower the audio quality.

What lossless audio compression does is retain every single bit of detail from the original recording, while still managing to reduce file sizes considerably. A typical song as it is on a CD takes about 50MB of memory. A decent-quality, 256kbps MP3 of the same song is around 5MB -- that's a massive amount of data lost in the compression process. A higher bit rate MP3 will give you a better quality audio file, and a larger file size, but it can still never touch the quality of the original recording. This is where lossless audio comes into play.

A typical song compressed into a lossless format, such as FLAC or Apple's Lossless audio format, clocks in at about 30MB on average. Although this is much smaller than the original 50MB file on a CD, it still retains every last bit of information.

How is this possible?

An extremely complex mathematical algorithm recognises sound patterns in an audio track. For example, let's say you have a series of numbers: 1234 1234 1234 1234 1234. Instead of using up storage space to remember each of those 20 digits, the lossless algorithm simply remembers '1234' and that it repeats five times: 1234 x 5. Notice how only five digits are used in total, instead of 20. Using this process, significantly less storage is needed overall.

To use lossless audio, you'll need a player that supports it. Some players, such as the TrekStor vibez or Cowon's iAudio 7, support the FLAC format. On the other hand, Apple's iPod video and nano ranges support Apple's own lossless format, ALAC. The main reason to use lossless audio is if you use a high-quality hi-fi speaker system at home, or if you use very expensive earphones. If you're just listening to music on your iPod, using the bundled headphones for the 30 minutes you commute to work, you don't need lossless audio.

If you're still unsure whether lossless audio is for you, the best method is to listen to a song in MP3 and the same song in lossless format. If you can't honestly tell the difference, stick with MP3. It's the most widely used format and you'll get heaps more music on your portable player by using it.

If you can tell the difference and appreciate the original recording quality of CDs, you should definitely consider a lossless audio format. Remember, you could always use lossless at home and MP3 on the move, since computer hard disks are vastly more capacious than portable music players.

Good luck!