Send a track into a large room and shut the room off partway through its decay. The gate is keyed to the source, so each transient opens it and the reverb behind that transient is heard only for as long as the hold allows.
Threshold, hold, release
Threshold is the source level that opens the gate. It is measured against full scale, so it moves with how loud the file is: a track sitting 20 dB down needs a lower threshold than one mastered to the ceiling.
Hold is how long the gate stays open after the last sample that crossed the threshold. This is the control that sets the length of the effect, and it is what you reach for first. Between 150 ms and 250 ms is the range most drum recordings sit in.
Release is how fast the gate closes once hold expires. Under 30 ms it cuts, which is the sound the effect is named for. Past 100 ms it starts to behave like a short reverb rather than a gated one.
Room size and damping
Room size raises the feedback inside the reverb, which lengthens the decay. Because the gate is cutting that decay off anyway, a large room here is not about length. It is about density: more reflections arrive in the window the gate leaves open.
Damping puts a low-pass filter in the feedback path so each pass loses more treble than the last. Low damping keeps the room bright, which is most of the character of the original recordings. Turning damping up darkens the burst and makes it sit further back.
Source material
The effect needs transients with gaps between them. A snare hit opens the gate, the room answers, and the gate closes before the next hit. Sustained material never lets the gate close, so the result is ordinary reverb with an extra threshold control.
If the track is a full mix rather than a single instrument, apply the step to a range instead of the whole file. The region controls confine it to one span of the source and crossfade at each edge.
Where the tail goes
The export renders past the last sample of the source until the gate has closed and the room has fallen below the level worth writing. That is normally well under a second, because hold and release bound it rather than the decay time of the room.
The preview follows the source, so it ends when the source ends. Judge the tail from the exported file.
Mix
Mix balances the dry signal against the gated room. At 0 the audio passes through untouched and the reverb is skipped rather than mixed in at zero level. On drums, somewhere between 30% and 60% keeps the hit in front of the burst.