Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Sound Devices (hierarchy name)
5. sound devices (equipment)

Anotations

Scope note:

Devices comprised of one or two pendant bobs suspended from a steel piller that strike a block affixed to the base. A graduated arc emerges from block that marks the arc of the pendulum. This measures the instensity of sound in relation to speed and distance of the pedulum strike.