To reduce reverberation in a room, where should sound-absorbing material be most effectively placed?

• A. On the floor under the sound source.
• B. On the same wall as the sound source.
• C. On all four walls equally.
• D. On the ceiling and on the wall opposite the sound source.

Answer: (D)

Reducing reverberation works best when you intercept the strongest reflected sound energy before it keeps bouncing around the room. In most rooms, the primary reflections that sustain reverberation travel from the source to the ceiling and to the wall opposite the source, then back toward the listener. Placing sound-absorbing material on the ceiling and on that opposite wall absorbs those key reflections, shortening the reverberation time and making speech or music clearer. Other placements—like under the source on the floor or on the same wall as the source—catch some energy but don’t target the main reflection paths as effectively. Even spreading absorption on all walls helps, but the ceiling and far wall provide the most impactful first-line reduction.