NCIDQ IDFX Practice Exam

Which of the following materials has the highest noise reduction coefficient?

1. Gypsum walls

2. 5/8" suspended acoustical ceiling tile

3. 1" fiberglass wall panel with fabric cover

4. 1" suspended acoustical tile

The correct answer is: 1" suspended acoustical tile

The material with the highest noise reduction coefficient (NRC) is typically designed to absorb sound effectively, minimizing reverberation and improving overall acoustics in a space. Suspended acoustical tiles are specifically engineered for sound absorption, utilizing materials that trap sound waves. In the context of this question, a 1" suspended acoustical tile is designed to absorb sound more efficiently than other materials mentioned. NRC ratings for these tiles are usually higher due to their fibrous or porous structure, which allows them to effectively absorb sound across a range of frequencies. This characteristic makes them particularly valuable in environments where noise reduction is a priority, such as offices, classrooms, and auditoriums. In contrast, gypsum walls, while they provide some level of sound isolation, are primarily solid and do not have the same absorption qualities as acoustical tiles. Similarly, a 5/8" suspended acoustical ceiling tile may have sound-deadening properties, but it generally does not offer the same level of absorption as the 1" tiles due to differences in thickness and material composition. Though 1" fiberglass wall panels with fabric covers can also provide good sound absorption, they may not achieve the same NRC as dedicated suspended acoustical tiles. Overall, the design and materials used