Manic compression: preserving audio quality

In order to store a sound on a computer, sound waves must be convereted to a digital format. The computer does this by ‘sampling’ each wave many times per second. The more samples that it takes every second, themore accurate the representation of the wave and the better the audio quality. CD-quality audio is sampled 44,100 times every second, and each sample is 16 bits in size.

By default, PCs store the date from a recorded sound wave as a Wav file unless compression is used. Wav files preserve the quality of the original audo but are generally latge, which is why the idea of compressing them to make them smaller is attractive, particularly to those who have portable music players with less storage space.

If you consider that a 70-minute CD album usually uses up an entire 700MB disc, you can work out that a Wav file containing one minute of audio wil use up 10MB of hard disk space.

If you want to archive your CD collection, condiser buying a large hard disk and storing the copies in the uncompressed Wav format to preserve the audio quality. You can then convert the tracks you want into MP3 format for use on your MP3 player. When a significantly better format comes along, you then convert your high-quality Wav files into that format directly rather than reconverting lower-quality MP3s, which would result in a loss of quality.