RT60 is defined as the time for reverberation to decay by what amount of signal level?

RT60 is defined as the time for reverberation to decay by what amount of signal level?

• A. 20 dB
• B. 40 dB
• C. 60 dB
• D. 80 dB

Answer: (C)

RT60 is the time it takes for reverberation to decay by 60 dB. In practice, you measure the room’s impulse response after the sound stops and determine how long the reverberant energy drops to 60 dB below the initial reverberant level. This 60 dB drop captures the tail end of the reverberant field, giving a stable metric of how long reflections persist in the space. The more absorption a room has, the shorter this decay time will be. In contrast, smaller decays (like 20 or 40 dB) don’t reflect the lasting tail, and an 80 dB drop is beyond the standard measure.

RT60 is the time it takes for reverberation to decay by 60 dB. In practice, you measure the room’s impulse response after the sound stops and determine how long the reverberant energy drops to 60 dB below the initial reverberant level. This 60 dB drop captures the tail end of the reverberant field, giving a stable metric of how long reflections persist in the space. The more absorption a room has, the shorter this decay time will be. In contrast, smaller decays (like 20 or 40 dB) don’t reflect the lasting tail, and an 80 dB drop is beyond the standard measure.