In an acoustical partition, what must be done with the wall cavities?

• A. Filled with appropriate sound insulation
• B. Left empty
• C. Filled with concrete
• D. Sealed with metal mesh

Answer: (A)

In acoustical partitions, the wall cavities must be filled with appropriate sound insulation. Air-filled cavities can carry and resonate sound, letting noise pass more easily from one side to the other. Filling them with materials like mineral wool or fiberglass adds mass and damping, creating a porous barrier that converts sound energy into heat and reduces transmission across a broad range of frequencies. It also helps minimize unwanted cavity resonances that can amplify certain sounds. Leaving the cavity empty would leave a direct path for sound; filling with concrete is impractical for typical partitions due to weight and construction issues; sealing with metal mesh does not provide the necessary insulating density and damping.