A reverberation, or reverb, is created when a sound is reflected off a surface and then reflected again and so on, until the sound is eventually absorbed. This creates an ambiance or decay, giving a sense of physical space to a sound. Sound engineers and electrical engineers have spent decades crafting machines and analog and digital processors do replicate and manipulate reverb. The most common reverb types are spring, plate, hall and chamber or church. The decay or "tail" or a reverb is defined by time, and the level of the effect by level, or on more advanced units, send and return. Check out the TC Electronic Hall of Fame 2, on of the most popular and best sounding digital reverbs out there. To untlock the ultimate ambient tone, consider experimenting with multiple combinations of effects, eg, analog delays, phasers, flangers or chorus pedals.