Blind users use AUI's which are constructed by mapping parts of GUIs to the AUI environment. After you 'touch' a buzzon in AUI space, you hear its function and can memorize it by its buzz. Then later you can 'hit' it to actually activate it.
Alarms can ping things and wake up if something is wrong.
Continuous signals can be used to show signal levels, and jitter. E.g., factory floors, network monitoring, surgical operating rooms, nurse stations. Music can be everywhere, random tracks cycling from CD players according to DJ's selections and to taste. Then the whole sound environment will become fabulous and refreshing. Devices and services could potentially take advantage of the 3D audio presentation facilities by representing their interface methods auditorily.