Digital audio has a few, very common uncompressed formats that it can use. They take PCM audio with the parameters described above, and wrap it up into a neat file. The two main formats you will find are CD Audio and WAV. You will often find other formats that simply specify a PCM type (linear, mu-Law, A-Law), a size (8-bit, 16-bit, 24-bit, etc), signed or unsigned, a frequency (32kHz, 44.1kHz, 48kHz), endianess (big or little), number of channels, and bit-rate.
CD Audio - The most common format you will find is CD audio, it is uncompressed audio. This format is 16-bit, Linear Pulse Code Modulation (L-PCM), signed data, running at a 44.1kHz sampling rate, with two channels of audio (stereo). It runs at 1411kbpsWAV - Unlike CD Audio, that specifies exact parameters, WAV files are capable of containing many different formats, however the most common one that it contains is identical to the CD audio format: 16-bit, L-PCM, signed, 44.1kHz. WAV files are almost always found with uncompressed data, however it is possible to use compression inside them.
MP2 - Stands for MPEG-1 audio, layer 2. Often used in
MP3 - Stands for MPEG-1 audio, layer 3. This is the most
popular audio format, as is evidenced by the number of MP3 players
available at electronics stores. Almost all computers and
consumer audio players can play this format. However, this format
is older and Vorbis, AAC, and WMA all offer superior compression ratios
for the same quality audio.
AC3 - This is also known as Dolby Digital sound, made popular by its
use in movie theaters. It is used on many DVDs and supports 5.1
FLAC - Free Lossless Audio Codec. This audio format was made
to take uncompressed formats and shrink them down, without losing any
quality at all. Audio in this format can be converted back to an
uncompressed format, and the resulting file would be identical to the
original uncompressed file. This is often used for editing and
archival, where you want to be sure not to lose any information.
Files are usually about half the size of an uncompressed file.
This format is open source, and free of royalties, so it can be used
Ogg/Vorbis - This is the leading open source compressed audio
format. Its compression is approximately twice as good as MP3, and
on par with AAC or WMA compression. This is the official standard for audio used in web pages.
AAC - Advanced Audio Codec This is Apple's primary audio
codec. It is available on Macintosh, in iTunes, and on
WMA - Windows Media Audio. This is Microsoft's primary audio
codec. It is available on Windows computers and many portable