Lesson 14: Signal Processing - Time Based - Reverb and Echo - Posted on 2015-05-19 by Jonathan Graham

Reverberation, or “reverb” for short, refers to the way sound waves reflect or “bounce” off different surfaces on their way to the listener’s ear. Sound waves can bounce backwards and forwards many times before dying away.

When sound waves reflect off walls, two things happen:

1. They take longer to reach the ear.
2. They lose energy (i.e., they get quieter) with each bounce.

Delay / Echo

Delay is a fairly simple idea: the original audio signal is followed close behind by a slightly delayed repeat, just like an echo. The delay time between the original sound and the repeat can range from a few milliseconds to several seconds. A delay effect can also involve single or multiple echoes, with each echo usually representing a quick reduction in relative sound level.

Reverberated signals may be divided into three components

• Direct Signal
• Early Reflections
• Reverberation
• Early reflections give the listener subconscious cues as to the size of the space.

Marjor Sources of Reverberation:

• Hall
• Chamber
• Room
• Spring