Millions have enjoyed recorded music since 1877 when Thomas Edison invented the phonograph. Then came radio, records, tapes and CD's. But today's digital audio players are a quantum leap forward in music technology. To understand what makes these music players so revolutionary, let's explore the question, "How do mp3 players work?"

Until recently listening to music recordings involved mechanically moving the media past an interface to pick up an analog signal called a wave-form. This signal of vibrations was amplified and sent to the speakers where we heard it as sounds. When digitized, the wave-form becomes a WAV file. It's a major improvement, but the file is very large and a CD disc is limited to about 80 minutes of music.

So What is an iPod, and How does an iPod work?

Apple's iPod is the best known mp3 player. In answer to the question, How do iPods work, the next two paragraphs really describe how all portable digital music players function.

Software converts the music to a small digital file, usually WAV to mp3, using a codec like MP3 or WMA. The codec compresses the file by discarding sounds inaudible to the human ear. The digital file is stored in the mp3 player's flash or micro-drive memory. Because the file is so small, a player no larger than a deck of cards can hold up to thousands of songs.

For play-back the mp3 player executes several functions. Embedded software reads the file, decompresses the encoding, converts it back to analog, amplifies the signal and sends it to the headphones. And voil, we have crystal clear sound without the annoying cracks, pops and hisses particularly common to records and tapes.

How We Do MP3 (Player Types, Functions & Features)

Even with a seemingly never-ending stream of new products, there are basically three types of audio devices that work well for audio CD duplication in a portable personal player.

1. Flash Players - the smallest, least expensive, and most reliable. Using solid state memory with embedded software, they have no moving parts, so batteries last longer and skips are eliminated. They have limited memory, but will still hold dozens of songs. Most players have search, shuffle, repeat and other popular features.

2. Micro-Drive Players - the tiny hard drives in these mp3 players have up to 60GB of memory and will hold thousands of tunes. Some also store and display photos. Anti-skip technology helps, but shock or vibration can still cause skips. They typically have more functions and features than flash players.

3. CD MP3 Players - the new generation of portable CD players. Using formats like mp3, WMA and ATRAC, they play (some also burn) CD's that hold 10 to 45 hours of music per disc. They play standard and/or 3" MiniDisc CD's. Standard CD sized units cost less than most mp3 players. MiniDisc player prices are higher but they hold the most music, and they're about the same size as a micro-drive mp3 player. Most play both pre-recorded and CD-R/RW discs. Features are similar to the other players.

For more information, see Compare MP3 Players