Allows applications to play and record sounds using the built-in sound hardware found on the Macintosh. It supports 16-bit CD-quality audio, better multi-channel sound and performance, redirection of sound to third-party hardware cards and plug-in audio compression/decompression software codes. Sound Manager also provides low level services which allow QuickTime to play and mix digital audio. Unnecessary if sound is not an issue; say, if you use ONLY spreadsheet and word processing programs. For System 7 or later.