What does it do?
Reverberation is a ubiquitous effect - you hear it all around you every day. It is simply the ambience of any environment, either natural or artificial.
You can’t have failed to notice, for instance, that your voice sounds different in a stairwell than it does in a tiled bathroom (which is why people like to sing in the shower). That’s because sound bounces off the smooth surfaces and moves around each space in a specific way.
Reverberation simulates this effect, providing lots of emulated environments that you can use to give your tracks a sense of space.
How does it work?
Reverberation comprises many tiny echoes that bounce off surfaces and return to the ear at different times, with changes in pitch and volume.
Manufacturers have utilised different approaches to achieve this effect. Older hardware units might bounce the sound off a suspended metal plate or metal springs in a box. Many digital reverb processors do it by creating and manipulating a number of echoes (see Delay, on the next slide).
Convolution or ‘impulse’ reverbs use mathematical analyses of signals in real spaces that recreate the effect on an incoming signal. Usually you can control the decay or room size, the amount of delay before the echoes and more.
Use it on...
Reverb can be used on everything you want to put in a ‘space’. Use it sparingly on lead vocals and instruments, since it will cause them to sound further away. It works great on drums to give a sense of ambience and cohesion.