- It's a small, quiet, low-power weapon, used like a pistol and readily concealable.
- Fires focused infrasound or ultrasound
- Usually does no damage to inanimate objects, but if plot-convenient may shatter crystal or damage delicate electronics.
- It is nonlethal, but it knocks you unconscious. A near miss may induce partial paralysis or a pins-and-needles sensation.
- When you wake up hours later, you will probably have one or more of: pins-and-needles, a violent headache, nausea, muscle aches. This side effect is commonly called stun shock or stun sickness.
- It's a short range weapon, with the effect blocked by walls and heavy furniture.
- Stunners are often available even in societies with hard controls on lethal weapons.
In genre SF after the mid-1950s, anything called a stunner or stun gun without qualification probably has the performance traits and role of a sonic stunner. Earlier stunners in genre SF were Static Stun Guns. One functional difference is that sonic stunners are more likely to have stunner-sickness aftereffects.
In theory a device that works using beams of focused sound ought to allow for bank shots off any sufficiently hard, flat surface, including accidental self-stunning if the reflection hits the shooter. The problem is worsened by the fact that a right-angled reflector (like the corner of a room) will always reflect the beam back the way it came. In practice this never seems to happen.
This trope isn't as common in visual media, which favors more lethal and flashier weapons (and thus the visually more interesting Static Stun Gun). When you do see a sonic stunner in film or TV, it tends to be something of a subtle Shout-Out by writers making a point of their genre-SF roots.
Not to be confused with the sonic screwdriver, which is a tool rather than a weapon.
- In Naruto, several ninja from the Sound Village use abilities with these effects such as Dosu's Melody Arm and Kin's bells. Kabuto has a jutsu that combines this with a bright shining light blinding and disorienting enemies at the same time.
- Sailor Moon: A less used secondary power, Sailor Moon can cry to the point where it becomes ultrasonic waves, shattering glass, stunning enemies and rendering weaker ones unconscious. Since her odango barrettes glow when she does this, its ambiguous whether the power is a function of her Hair Decorations, or inherently hers.
- In Superman/Doomsday: Hunter/Prey, Superman uses a sonic weapon to incapacitate Doomsday in his battle with the creature on Calaton, but Doomsday seals up his ear canals to make the weapon ineffective.
- John is hit with one of these in The Keys Stand Alone: The Soft World because the Circle (rightly) thinks it will cause him pain and disable him. However, he has his water field up, which blunts the effect, and when he manages to stagger behind a tree the effect is cut off entirely.
- "Police Operation", H. Beam Piper, 1948: "ultrasonic paralyzers", described as 18-inch wands with bulbous ends. The effect is unreliable and it is implied there is no stun shock.
- "Null ABC", H. Beam Piper and John Joseph McGuire, 1953: describes a "sono-gun"; the victims will wake up with headaches.
- In Randall Garret's 1954 story "The Hunting Lodge", the weapon has a "supersonic whistle" in its barrel and the protagonist describes stun shock. This is probably the Trope Codifier,
- Sonic stunners feature in Larry Niven's Known Space universe, from 1964 onwards. The stories include several references to "dueling stunners", and in one the stun sound is amplified through speakers to knock out everyone on a space station.
- And in Frank Herbert's Dune and sequels, from 1965 onwards
- And in Lois Bujold's Vorkosigan Saga stories, from 1986 onwards. Bujold's characters joke about "stunner tag" in a way that suggests it has become an almost ritualized substitute for more lethal confrontations. Stun shock is definite with these.
- In The League of Peoples Verse, sonic stunners are the standard weapon carried by Explorers, as lethal weapons are prohibited by the League. They are supposed to cause six hours of unconsciousness, but in practice their effects vary wildly from species to species.
- The Star Wars Expanded Universe features sonic weapons capable of both stunning (by deafening and disrupting equilibrium) and killing (by making things shatter).
- Choices of One has Mara Jade use a "sonic", a disk that she presses against the throat of a stormtrooper to knock him out.
- In the Steam Punk world of Boneshaker, Dr. Minnerichts Doozy Dazer can stun rotters for about three minutes.
- Marvel Cinematic Universe:
Stane: It's a shame the government didn't approve. There are so many applications regarding short-term paralysis.
- The Incredible Hulk: The military uses giant sound wave cannons to incapacitate the Hulk.
- Iron Man has Obadiah Stane using a small device twice. It emits a high-pitched sound that paralyzes anyone for 15 minutes who is not wearing special ear protection.
- Captain America: Civil War:
- Tony Stark's collapsible gauntlet includes a sonic weapon that he uses against Bucky, momentarily stunning him and allowing Tony to get close enough to disarm him.
- War Machine has a more powerful, wrist-mounted version which he uses to knock out Scarlet Witch. It's far less effective against Giant-Man, though.
- In Black Panther, Wakanda uses a special sonic frequency to suppress the properties of Vibranium, as otherwise its energy-absorbing-and-redirecting nature makes it incredibly dangerous to transport. The climactic battle between Black Panther and Killmonger takes place on a Vibranium supply railroad that emits this frequency, with both their Vibranium nanobot suits partially dissolving when exposed to it, which gives Black Panther the opening to stab Killmonger. Shuri also wields a pair of Arm Cannons armed with this frequency during an earlier battle with Killmonger.
- Madame Sin (1972). A secret agent is knocked unconscious by one so he can be kidnapped, and he's informed that extended exposure would "collapse the brain" of the target. Sure enough the weapon is used on him again once he's served his purpose, though the hero escapes albeit at the cost of losing his hearing for some time.
- Sonic stunners are standard-issue Alliance subdual weapons in Firefly. You can see them in action in "Ariel" (though they do nothing to blast open a locked door, to Jayne's dismay) and in "Trash".
- The Tekwar Made For TV Movies and short-lived TV series had non-lethal "pulse guns" - these were the only weapons the ex-con protagonist was legally permitted to carry. They used the same cheap special effect as Babylon 5 - the "pulses" fired heat shimmer-like distortions.
- JAG: The other method used by the UFO in "Sightings" to subdue and intimidate people.
- Quinn builds an unreliable sonic stun bomb in Zoey 101.
- Stutter weapons are used in Alternity's Star*Drive setting. They deal very high subdual damage but have poor performance against armor. (They also presumably don't work in a vacuum.)
- Sonic stunners are available in BattleTech to infantry, though not as a common battlefield weapon—instead they're usually issued to civilian police or a base's MP corps. They don't do any permanent damage, operate on an ultrasound frequency, and are very power-efficient, though their range is short. This also makes them ideal as espionage or infiltration gear.
- Warhammer 40K: Subverted with Noise Marines, who very much want their victims to hear their hideously-distorted music and overload their senses with noise (dubstep is a popular representation of this effect).
- In Mario Kart 8, a new item is introduced called the Super Horn. It can be used to attack drivers in close proximity, but its main purpose is blocking items from hitting you, particularly the dreaded Spiny Blue Shell.
- In Afterlife Blues, Liraz uses a Sonic Stunner to keep Brody from running.
- In Schlock Mercenary, the first time Sergeant Schlock's plasma cannon is destroyed, Commander Kevin tries replacing it with one of these. He... isn't very happy with that, as they're useless for intimidation. The concept has made a couple of appearances since then, but they've mostly switched to using "goober guns" for situations where the enemy needs to be restrained without being killed.
- In real life, the term "stun gun" is used for Taser-like electric-shock weapons. SF use of the term predates these by decades, and almost certainly influenced the marketing of these devices.
- Infrasound (sound waves below 20Hz in frequency) genuinely produces some odd physiological effects. According to Wikipedia, it may trigger feelings of awe or fear in humans, and it has been observed to cause difficulties in breathing and digestion in humans and animals. The nausea and headaches associated with this trope are real physiological side-effects of exposure to intense infrasound.
- The Flashbang grenade, which as the name suggests, works by simultaneously creating a blinding flash and a deafening bang upon explosion to stun unprotected people within the area.
- The pistol shrimp utilizes a large asymmetrical claw as one of these. Snapped faster then a man can blink, the resulting cavitation produces a pressure wave measured in dozens of atmospheres, capable of killing small fish, and stunning larger ones. It's also handy for long-distance communication.
- The Sperm Whale can stun a Giant Squid with its echolocation, which is released not by its mouth, but the large forehead area. No wonder those things are so huge.
- The LRAD, originally developed for long-distance communication, also has applications in less-than-lethal crowd control.