MP3 Players - Technical Details

Cheap MP3 players have become an integral part of our everyday lives, along with ubiquitous cell phone the laptop computer!  The convenience of having your music in MP3 format as opposed to conventional CDs is undeniable, and evident for all to see.  This article discusses the technical aspects of the MP3 format and players.

On most music CDs, each song is stored in digital format as a WAV file.  On average, one minute of music in this format can require between one and two megabytes of storage space.  This allows for storage of only 10 to 15 songs on most CDs.  MP3 technology seeks to compress the file size considerable making use of something called the “lossy compression algorithm” and the science of psychoacoustics.  Within the range of human hearing, our ear has limitations on distinguishing between multiple notes being played simultaneously.  For example, two notes of the same strength played simultaneously would likely be heard as a single note, with one note masking the other.  The perception of human hearing has been described as a series of mathematical equations, and the lossy compression algorithm provides a roadmap to strip out the notes that cannot be discerned by the human ear.  The resulting file is then compressed a second time, and the file is now in MP3 format.  The MP3 file is typically one tenth of the original file size.  Compressions of less than one twelfth are possible, but at these high compressions, the loss of audio quality becomes significant.

This MP3 file can then be downloaded on to an MP3 player.  Most digital music players consist of a file storage unit, an electronic play back unit, a battery power supply, and headphones or earbuds.  The storage, playback, and power supply units are housed in a protective casing.  The file storage unit can be either a hard drive or a flash memory card.  Hard drives usually have much higher storage capacities than flash memory units, but can suffer from “skipping” and consume more power than flash memory.  The battery powers the MP3 player.  It can be a built-in rechargeable battery or an external AAA size battery that needs to be inserted into the player.  The economy of a built-in rechargeable battery is obvious, but you will need to plug the player into the USB port of your computer in order to charge the battery.  In that respect, units with the AAA batteries are more convenient.