7. Audio Formats
Some of the main formats of interest in digital audio are wave (.wav), MP3 (.mp3), MIDI (.mid), RealAudio (.ra), and Windows Media (.wma). Each format has its particular strengths and specific uses. Wave and MP3 files are the two kinds of files generally involved in creating custom CDs. When you convert analog sound to digital by recording music with your computer, the resulting file will be in wave (.wav) format.
Wave (.wav) Wave is the standard form for uncompressed audio on a PC. Since a wave file is uncompressed data - as close a copy to the original analog data as possible - it is therefore much larger than the same file would be in a compressed format such as mp3 or RealAudio. Audio CDs store their audio in, essentially, the wave format. Your audio will need to be in this format in order to be edited using a wave editor, or burned to an audio CD that will play in your home stereo.
MP3 (.mp3) is a popular compressed audio format widely used to transfer music over the internet. MP3s are created by taking wave audio data and processing it with a special algorithm. This alrgorithm removes parts of the audio that theoretically cannot be detected with the human ear; in actuality, there will be some degradation of quality, but this depends on the quality (bitrate) with which you choose to encode the file.
The net result is an MP3 file which is vastly smaller than the original wave file, but sounds very nearly as good. As an example of the huge size different between a wave file and an MP3, a three minute song will take up 30 Mb as a wave file, but only between 2 and 7 Mb as an MP3 (depending on the bitrate you choose). This explains why MP3 files are so popular for trading music on the internet.
Note: though they are controversial because of certain copyright abuses, MP3 files themselves are not illegal. Blaze Audio's RipEditBurn Plus and Wave Creator each allow you to convert MP3 files to wave files, or wave files to MP3 files. Give it a try!
RealAudio (.ra) is a streaming audio format often used by internet radio stations and for posting sound files on websites. RealAudio files are smaller even than MP3 files - around 500 Kb a song - but are of lower quality if compressed enough to play over a slow connection (such as a 56 kbps modem).
MIDI (.mid) is an entirely different sort of file. Unlike the previous two formats, it is not compressed audio. MIDI is a kind of ?language? that allows computers and certain musical instruments to communicate. This language consists of instructions telling the instrument (or the MIDI synthesizer in your sound card) which notes to play, with what instrument, and when. MIDI can be used entirely within a computer, with no external instruments. MIDI files have a synthesized sound, and are quite small, around 30-60 Kb for your average song. One fun feature of MIDI files is that you can add and synchronize song lyrics to create Karaoke files (.mid and .kar). MIDI and Karaoke files are widely available on the internet as well. Blaze Audio?s MIDIMaster Karaoke works great as a midi player as well as a karaoke player.
Windows Media (.wma) is a format similar to MP3. This is essentially a competing format created by Microsoft and used primarily in Windows Media Player and other compatible programs. Microsoft claims that Windows Media files are even better than MP3 files, but MP3 files are still much more prevalent on the internet.
