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The Formats of Sound

An excerpt from the

Every program category has its standard file formats, and sound-editing software is no exception. Although the SoundEdit application has its own file format, it also supports two important standard formats -- SND resources (also known as sound or `snd' resources) and Audio Interchange File Format. Here's a summary of the most popular formats.

SND resources

If there's a sound you want to use as a system-error beep or in a HyperCard stack, you must save it as an SND resource. Technically, two types of SND resources exist. Format 1 resources are generally system beeps, and Format 2 resources are used by HyperCard and other sound-playing applications.

(Historical note: In the early days of digital Mac sound, the distinction was more important; you couldn't use Format 2 SND resources as system beeps. Beginning with System 6.0.2, however, Apple made the Mac's Sound Manager a bit less picky. With System 6.0.2 and later versions, you can use either format for system beeps.)

AIFF files

The Audio Interchange File Format (commonly referred to as either AIFF or Audio IFF) lets one program open a digital recording created by another program--it's the PICT format of the digital audio world.

You can find support for AIFF files in professionally oriented sound software such as Passport Designs' Alchemy and Digidesign's Sound Designer, as well as in sound-editing programs such as SoundEdit 16 and OSC's Deck II, and in video-editing packages such as Adobe Premiere. AIFF is the preferred format for swapping files between such programs.

System 7 sound files

Sometimes called the sfil format, this is the format that allows you to play sounds by double-clicking them at the Finder. One time you might want to use this format is when creating a special error beep sound.

WAV files

This is a common file format in the DOS/Windows world. WAV files generally end with the characters .WAV. SoundEdit 16 can open and save WAV files, as can S/Link, a sound-conversion utility from New England Digital.

MOD files

The MOD format is a special format that stores sound samples. Originally developed for the Commodore Amiga computer, MOD files are used by music programs such as Sound-Trecker, which is included on the Macworld Power User Clinic CD that's included with the Macworld New Complete Mac Handbook.

.au files

Also called Sun audio, this is a common file format on the World Wide Web. You can play .au files on the Macintosh using a variety of shareware or freeware utilities, including SoundMachine and SoundApp.

.RA files

Another Web-oriented sound format, this is format used by Progressive Networks's RealAudio technology, which allows for real-time audio over the internet.

MPEG files

Short for Motion Picture Experts Group, MPEG is a data-compression standard most commonly associated with digital video. But it's also gaining popularity for distributing audio on the Web.