Pre-delay
The short gap between the dry signal and the start of the reverb – one knob that decides whether a voice stands in front of the room or inside it.
In a real space, the distance to the nearest wall sets the gap: the bigger the venue, the longer before the first bounce comes back. A reverb with 20–100 ms of pre-delay therefore sounds larger, but mostly it lets consonants through cleanly before the tail washes over them. That is why a vocal can carry plenty of reverb and still be intelligible.
Plate reverbs had no natural pre-delay, so 1970s engineers ran the send through a tape machine first. Modern DAWs usually let you sync the parameter to tempo, so the reverb blooms a sixteenth note after the hit rather than at some arbitrary millisecond.