Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Object Groupings and Systems (hierarchy name)
4. systems (equipment)
5. [systems by function]
6. communication systems (mechanical and electrical systems)
7. sound systems

Anotations

Scope note:

The combination of sound recording and transducing devices and associated equipment for picking up sound at one location and time and reproducing it at the same or another location at the same or different time.