Audio File Types

Hundreds of file formats exist for recording and playing digital sound and music files just as different physical methods of storing audio, that we use for different applications and reasons (vinyl records, tapes, compact discs, and now DVDs, etc.)

Why do we need more than one audio file format? Because you may want to use your audio data for different tasks, such as playback on a CD, music or sound effects in a video game, a film or video soundtrack, or even for downloading over the Internet. Each task may require that your audio data be saved in a different way. For example, audio for a CD must be stored using a bit depth of 16 and a 44.1 KHz sampling rate. But for downloading over the Internet, you use adifferent bit depth and sampling rate because at 16 bit, 44.1 KHz, every minute of stereo audio consumes about 10 MB of disk space! That’s a lot of data to push over a lowly phone line. They can be devided into three major groups:

  • - uncompressed audio file formats;
  • - audio file formats with lossless compression;
  • - audio file formats with lossy compression.

Uncompressed audio formats (often referred to as PCM formats) are just as the name suggests — formats that use no compression. This means all the data is available, at the risk of large file sizes. Uncompressed files are usually stored as .waw on windows or as .aiff files on Mac OS.

Lossless compressed audio files are the files compressed without the loss in quality. They require more processing time than an uncompressed format but take less space when stored. The most widespread lossless file formats are FLAC, WavPack, Monkey’s Audio, ALAC.

Lossy compression results in some loss of data as the compression algorithm eliminates redundant or unnecessary information — basically it tosses what it sees as irrelevant information. Lossy compression has become popular online because of its small file size; it is easier to transmit over the Internet. MP3 and Real Audio files uses a lossy compression as well as AAC, ATRAC and lossy Windows Media Audio (WMA) files.

So which format is the most convenient for an ordinary music lover? To sum it up, if you’re willing to sacrifice the storage space, and have ears sensitive enough to tell the difference between a CD and a ripped track, go with .wav or .aiff. Otherwise, .aac and .mp3 encoded at bitrates above 256 kbit/s are indistinguishable from CDs for the average person.