System 7 offers some exciting new sound capabilities that you will hear as
software developers revise their applications for sound.
For the first time, a Macintosh with System 7 can play several sounds at
once. For example, you could be playing a voice track and some other track
at the same time. In addition, you can work on other things while the
system plays a sound.
System 7 offers sound-input capabilities for the microphone included with
recent Macintoshes. With sound-in, applications can start offering
features like voice annotation of documents.
Finally, System 7 has built-in audio compression to save disk space, so you
can have larger sounds than before.