Obviously now digital reverberation is in almost universal use, and it can produce an almost totally believably natural sound, or it can be used to go beyond naturalness and creatively enhance a sound.
The main parameters of digital reverb are these:
- Reverberation time. As in acoustics, this is defined as the time it takes for the reverberation to decay by 60 dB.
- Early reflections. As in acoustics again, the earliest reflections are perceived separately. The character of these early reflections tell our ears a lot about the space we are in, and digital reverberation units will various combinations to simulate different acoustic environments.
- Pre-delay. It is often useful to separate reverberation in time from the original signal. Particularly with vocals, this allows a higher level of reverb while maintaining intelligibility.
- High frequency damping. It is common for real rooms with soft surfaces coverings to have a shorter reverberation time at HF than at LF. Digital reverb units simulate this.
Although any good digital reverberation unit will offer these parameters and many more, it is the overall character of the unit that is the most significant factor.
The most well-respected manufacturer of digital reverb units is Lexicon, whose 480L and 224XL are 'must have' equipment for any top recording studio.