What Is Reverb Time: Reverb time is defined as the time that a sound, once stopped, takes to decay by 60dB. A sound played in a room will bounce off the walls. If the walls do not absorb any sound, the volume in the room will continue to increase as long as sound is being added. Even if the sound were shut off, the volume would not drop because there would be no place for the sound to go. In any real room, the walls absorb sound. The more they absorb, the faster the volume will drop off after the sound in stopped. Certain materials, such as rugs, absorb a lot of sound. Materials such as plaster and glass absorb almost none. The absorption also varies with the frequency of sound. Large rooms have a much greater volume inside for the amount of wall surface, so they tend to have more reverb than small rooms.

Reverb time is our method of comparing the amount of bouncing sound (reverberation) in different rooms. (Echo is considered to be the result of a single bounce.)