Which of the following is NOT listed as a factor affecting reverberation time?

• A. Size of the space
• B. Color of the walls
• C. Materials within the space
• D. Shape of the space

Answer: (B)

Reverberation time depends on how sound energy is absorbed and reflected in a space, not on cosmetic details. The size of the space sets the room’s volume, so larger rooms give sound more room to bounce around before it dies away, typically increasing reverberation time. The materials within the space determine absorption: soft, porous surfaces (like carpets, curtains, or fabric panels) absorb more sound and shorten the persistence, while hard, reflective surfaces (like bare concrete or tile) reflect more sound and lengthen it. The shape of the room affects how reflections travel and diffuse, influencing how evenly the sound decays throughout the space. The color of the walls, being a cosmetic attribute, generally does not change these acoustic properties, so it does not meaningfully affect reverberation time.