here are many sound file formats to chose from. The format you pick will depend on your what your audience can use and the types of sounds you have. You can hear the same sound clip in the five most common formats on the Compare Sounds page.
Sound falls into one of two categories:
Recorded Sound. Recorded sound is a file that is a recording of actual sounds. Some sort of recording device captured the sound waves and turned them into a digital file.
Described Sound. Described, or mapped, sound files contain information about how the sound should be played. Instead of actual digital sound bits, these files contain instructions for playing the sound. The most common type of described sound file is the Musical Instrument Digital Interface (MIDI) file. A MIDI file contains the musical notes and their duration, rhythm, and other information about how to play them.
Other types of sound files that you may encounter on the Web are .ra, Real Audio files, Shockwave files, Flash files, and QuickTime files. Real Audio requires server software to deliver .ra files; describing this is beyond the scope of this audio zone. Shockwave and, Flash, have many other uses in addition to audio, placing them beyond the scope of this section also. QuickTime files are the above-mentioned .mov files.
AIF is a audio format that was developed by Apple Computer. Most recent browsers, including Microsoft IE and Netscape Navigator, will play an aif file using the browser’s built-in sound player. AIF files have one of these extenstions:
AU is one of the most common audio formats used on the Web. It was created by Sun Microsystems and is sometimes referred to as “audio/basic” format. Most browsers support the au format with their internal sound players. An au-formatted file has this extension:
The EA format was created by Geo and named after its Emblaze Audio creation products. It compresses audio files to a fraction of their original size and uses a Java applet to play back the file. This is the first audio format that was created specifically for Web-based audio. Any browser that supports Java will play a .ea file without requiring additional plug-ins. EA files have this extension:
MIDI stands for Musical Instrument Digital Interface. MIDI is typically used to play music.
MIDI files contain a set of instruction that your computer sends to a sound card, synthesizer, or other device. MIDI files contain information about how to play the sound, rather than recording an actual rendition of the sound. They contain information about musical notes and which instruments play those notes.
The quality of MIDI sound on the Web depends on the quality of the MIDI interpreter in the computer’s sound card. For example, MIDI files sound very nice on WebTV because the WebTV MIDI interpreter does a high-quality job translating and “displaying” the sound.
MIDI files have one of these extensions:
WAV is Microsoft’s audio format of choice. Since Windows 3.1, WAV has been the native format for sound within the Windows environment. Needless to say, this makes it one of the most common sound formats on the Web. Most browsers support the .wav format with their internal sound players. A .wav-formatted file has this extension:
Compare Sound Files
This page has examples of the different sound files in one place. Each sound is the “same” sound, captured using a different technology. Your particular brower and platform combination may support some or all of the examples.
We are presenting these files in their rawest form. Nothing special has been done to their presentation (we’ll show you how to improve their presentation in the Audio Basics section). In some cases, clicking on the sound may launch a player plug-in. Depending on your configuration, the player may automatically open a new page and you’ll need to press the BACK button to return to this page after the sound has played.
We present these in their raw forms so you can see and hear the areas that you’ll need to tweak as you incorporate audio into your own site. The task is not overwhelming and you can learn how to do it, but there is a process involved when presenting sound well within a Web site.