Interior Design Implementation (IDIX) 2 Practice Exam 2026 – The Complete All-in-One Guide to Master Your Certification!

The key idea is measuring how much sound energy a material absorbs rather than reflects or passes through. This is quantified by the absorption coefficient, which expresses the fraction of incident airborne sound energy that the material absorbs. The term that matches this definition exactly is the sound absorption coefficient, since it directly describes the material’s ability to take in sound energy.

The other terms don’t fit as precisely. Noise Reduction Coefficient is a single-number average of absorption over several mid-frequency bands, used for quick comparisons rather than representing the fundamental absorption property at a given frequency. Transmission Loss speaks to how much sound is blocked by a barrier as a whole, not how much energy a material absorbs on the surface. Sound Attenuation Batts isn’t a standard, well-defined term in acoustics.