Before a big explosion, there is a very short buildup towards the explosion, this is done more for the awe effect and usually doesn't actually have any meaning or explanation, audible and visible to the viewer, but not necessarily a part of the universe. If a bomb literally needs to build up power before it explodes then it probably isn't a part of this trope, especially not if it takes a while. (though it could be)
Often only takes a second, before the big boom, you will hear a very soft sucking sound, or a warping sound. In some more exotic examples, the sound will temporarily disappear. Sometimes accompanied by a Pre-Explosion Glow. Or a visible ripple and warping effect in the surroundings or the bomb will be shown Sucking-In Lines.
- In The Life and Times of Scrooge McDuck interquel "The Cowboy Captain of the Cutty Sark", Scrooge is part of the Cutty Sark's crew when they become witness to the eruption of the island of Krakatoa in 1883. At first, everyone on deck just sees an exploding island with no sound; Gyro Gearloose's father points out that light travels faster. Luckily enough, this gives them enough time to prepare for the coming sound burst, heat wave, tsunami, and discharge of volcanic rock that follow.
- In Attack of the Clones, Jango Fett uses "seismic charges" against Obi-Wan. Before they explode, there is a second of complete silence. Even the audible silence of space stops for a moment.
- In The Last Jedi there is complete and total silence for around 10 seconds when the Raddus slams into the Supremacy at lightspeed, tearing a massive gash of stunning bright light through the entire ship. The deafening roar of the explosion's shockwave (again, through space) only comes well after the initial brilliance of destruction.
- Krypton exploding in Superman Returns uses this effect.
- The Matrix is a heavy user of this trope. Justified to some extent as a side-effect of the Matrix's processors being unable to keep up with the unanticipated actions of the heroes.
- In The Lord of the Rings: The Return of the King, this is heard before the big green bolt of garrison-light bursts out of Minas Morgul towards the sky. Barad-Dur also has this effect - the eye of Sauron gets "sucked" into the tower and explodes as the tower crumbles.
- Terminator 2: Judgment Day had the dream sequence where Sarah Connor imagines herself getting killed by a nuclear weapon fired by Skynet: First there is a blinding light and a heat wave, causing everything to catch fire. Then comes the shockwave with accompanying sound and mushroom cloud, which flattens buildings, throws cars around, uproots trees and causes the charred remains of people to scatter into the air like leaves.
- Watchmen uses this with the Dr. Manhattan bombs, where the sphere of Applied Phlebotinum shrinks into nothingness and is followed by the blast a moment of silence later.
- Star Trek is also a big offender. A variety of effects are used for different explosions.
- When Tyrael blows up the World Stone in the epilogue of Diablo II: Lord of Destruction, a warping sound can be heard before the stone goes boom.
- In fact, this effect is tripled:
- There is a moment of silence after Tyrael charges up the sword (and a slowmotion effect when he throws it) that reaches its pinnacle when the sword enters the stone. Then the dimensions around the stone start to ripple.
- The stone slowly disintegrates, and as it reaches its ends, it builds up to a final explosion, this explosion is preluded by the now familiar pre-explosion warping sound.
- But then it turns out that there is a second, even louder explosion, that comes after a softer explosion, the softer explosion thus itself becomes the pre-explosion warp.
- In fact, this effect is tripled:
- Halo: Present in Halo 2 and Halo 3. When a Covenant vehicle is destroyed (except for Brute manufactured ones) it will explode once then almost invariably produce a strange whine and explode again. This is justified as the vehicle's plasma coil going critical.
- The fate of the evil space ship in the finale of Elite Beat Agents.
- Star Fox 64 has a remarkable numerical example when unlocking the hard path from Macbeth.
- In Titan A.E., the Drej Planet Killer first turns on a targeting/focusing beam, then hits the planet with an energy burst, causing shockwaves to ripple around the planet surface while the seas boil and the continents burn, and finally the entire planet erupts like a volcano, shattering it to tectonic-plate-sized pieces.