Which ASTM standard measures airborne sound between rooms sharing plenum?

• A. ASTM E90 measures airborne sound between partitions
• B. ASTM E414 measures airborne sound between rooms sharing plenum
• C. ASTM E336 measures airborne sound between partitions
• D. ASTM E492 measures impact sound

Answer: (B)

When a plenum sits between two rooms, sound can travel not just through the partition but also through that air cavity path, so the test method must specifically account for the plenum in the transmission path. The standard that defines how to measure airborne sound attenuation between rooms sharing a plenum is ASTM E336. It describes the test setup, instrumentation, and calculations needed to capture the sound transmission through the plenum path as part of the overall attenuation between the rooms. This ensures the results reflect real-world conditions where air ducts or cavities between spaces can carry sound. By contrast, other standards focus on different configurations—such as lab measurements of partitions without a plenum or other sound transmission scenarios like impact noise—so they don’t provide the proper method for rooms that share a plenum.