There are many different formats for digital audio files, each with their own advantages and disadvantages. Some of these digital audio formats have been around for many years, while some are new and improved. The world of digital audio changes almost every day, as more and more people turn to portable music players, digital home audio systems, and digital music for their cars.

There are three basic types of digital audio file: uncompressed, or ‘common’ systems, such as the WAV format; formats which use a compression technique, but lose absolutely none of the data in the compression, known as loss-less compression; and formats which do lose some of the original data, but retain a fairly high quality, known as lossy compression.

The WAV format is the most common of the common digital audio types. It is an older format, made as a joint effort between IBM and Microsoft as a way to put digital audio on personal computers. WAV files tend to be very large, since they are not compressed at all, so it is rare to find them online or where space is at a premium. WAVs are used where space is not a huge issue, or where compression is not possible for other reasons — standard compact discs, for example, use an uncompressed digital audio file using pulse-code modulation (PCM).

The MP3 format is probably the most well known digital audio format, and is a good example of a lossy compression system. The MP3 format was developed in the late 1980s, and had a huge spike in popularity in the mid-1990s with the popularity of the Internet as a file-sharing medium. MP3 files are ideal for sharing online, or in any context where space is at a premium, because they can be compressed down to much smaller sizes than WAV formats. The quality is reduced — most MP3s are encoded at anywhere between 160 and 320 kb/s, as opposed to the 1411.2 kb/s of a WAV file — but for many people the loss of sound fidelity is unnoticeable, especially with cheaper speakers.

AAC, or Advanced Audio Coding, is another digital audio format which has seen huge popularity in the Internet age. It is a newer compression system, and is generally agreed upon as having a higher-quality sound at the same compression levels as MP3. AAC is also able to accept digital rights management (DRM) systems, which limit how the files can be used or transported. The best example of this is Apple’s use of the AAC format, wrapping it in their DRM system, FairPlay, and putting it in its own container, with the .mp4 extension. While normal AAC files are compatible with a wide range of operating systems and devices, AAC files in a .mp4 wrapper are compatible only with Apple’s software, and their iPod device.

The Vorbis format is a lesser-known, but still widely-popular, digital audio format, similar to MP3 or AAC. Vorbis was conceived of as an alternative to MP3, when there was a threat that MP3 would become a pay-for-licensing format. Vorbis files are suffixed with the .ogg extension, and in this wrapper are known as Ogg Vorbis files. The quality of Vorbis is comparable to MP3 — some would say it performs better in some situations — but its success comes from the fact that it is unpatented. Vorbis usually sees the most popularity among proponents of the Open Source movement.