Transmission loss describes the reduction of sound as it passes through a barrier between spaces. Which term is this property most closely associated with?

• A. Transmission Loss
• B. Noise Reduction Coefficient
• C. Sound Absorption Coefficient
• D. Impact Insulation Class

Answer: (A)

Transmission loss measures how much airborne sound energy is reduced as it passes through a barrier between spaces. It directly describes the barrier’s ability to block sound from one side to the other, with higher loss meaning better isolation. This concept is the basis for how walls and partitions are compared in building design. The other terms refer to different acoustic phenomena: a material’s noise reduction coefficient describes how much incident sound energy is absorbed inside a room, not transmitted through a barrier; the sound absorption coefficient also measures absorption at a surface rather than transmission; and impact insulation class evaluates the protection against impact sounds like footsteps, which is a different path of noise transfer. So the term that best fits the description is transmission loss.