Almost no shark is known to make sound deliberately: sharks have no swim bladder and none of the drumming muscles that noisy bony fish use, and for more than a century not one species had ever been recorded producing a sound on purpose.
That changed with the rig, a small houndshark from New Zealand, which was recorded making short, high-frequency clicks when handled. It remains the only shark with a documented sound of its own. Everything else a shark emits — snapping jaws, scraping teeth, displaced water — is a by-product of moving and feeding, not a signal.
- Sharks known to clickOne: the rig
- Hearing rangeRoughly 10–800 Hz
- Sound-producing organNone known in sharks
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Why sharks were filed under silent
Most of the noise in the sea comes from bony fish, and most of that comes from one piece of equipment sharks do not have. A swim bladder is a gas-filled sac used for buoyancy, and in hundreds of species it doubles as a drum: fast sonic muscles attached to its wall contract dozens of times a second and the bladder radiates the vibration into the water. That is where the grunts, croaks and boat-hull knocking of a reef at dusk come from.
Sharks have no swim bladder at all. They stay off the bottom using a huge oil-rich liver and the lift generated by their fins, an arrangement covered in how a shark's body is built. Without a gas chamber there is nothing to resonate, and no shark has ever been found with the specialised sonic musculature that bony fish carry.
Nor is there a voice in the mammal sense. Sharks have no lungs, no larynx and no vocal folds; water enters the mouth and leaves through the gill slits in a one-way flow that never passes over a vibrating membrane. So the working assumption for a century was straightforward — sharks listen, and they do not speak.
The one shark that has been caught making a sound
The exception arrived from New Zealand. Researchers working with the rig, Mustelus lenticulatus — the small estuary houndshark the site profiles as the spotted estuary smooth-hound — recorded sharp clicks from the animals while they were being held during hearing experiments. The recordings were published in 2025 and represent the first documented case of active sound production by any shark.
The clicks are brief and high-pitched, with most of their energy above roughly 2 kHz and source levels of the order of 156 decibels. That pitch is well above the range the rig itself can hear, which is the detail that makes the finding awkward to interpret. The likely mechanism is mechanical: the rig's flattened, plate-like crushing teeth snapping together as the jaws close hard.
The behaviour also faded. Clicking was concentrated in the first seconds of handling and dropped off as the sharks settled, which reads more like a startle response than a conversation. Nobody has yet recorded a rig clicking in the wild, and no second species has joined it. One shark, one sound, one set of experiments — that is the entire evidence base.
The noise sharks make without meaning to
Silent as a category does not mean silent in practice. A large shark is a big object moving fast through a dense medium, and that is audible on a hydrophone even when nothing is being produced on purpose.
Jaws closing on bone make a distinct crack. Teeth scraping across a turtle shell or a boat hull grate. A great white breaching and landing generates an impact you can hear from a long way off, and surface feeding adds the slap of the tail and the collapse of entrained air bubbles. Bottom feeders add their own sounds: a nurse shark using suction to pull a fish from a crevice produces an audible thump as the mouth floor drops.
None of this is signalling. Every one of these noises is the acoustic shadow of a mechanical action, and a shark gains nothing from producing it — if anything, quiet is an advantage to an ambush hunter. The distinction matters because popular accounts often blur the two, treating the sound of a shark doing something as evidence that the shark meant to make a sound.
What sharks hear, which is the real story
The interesting half of shark acoustics runs in the other direction. Sharks are excellent low-frequency listeners, sensitive to roughly 10 to 800 hertz and most responsive well below 400 hertz — a band that sits underneath most of the ocean's biological chatter and carries a long way.
There are no external ear openings. Two small pores on top of the head lead down to an inner ear on each side, housing three semicircular canals and a sensory patch called the macula neglecta that is unusually well developed in sharks. Alongside it runs the lateral line, a canal system that registers water movement close to the body. Together they give a shark a picture of what is moving nearby, complementing smell and the electrical sense described in our entry on the ampullae of Lorenzini.
Field experiments from the 1960s onwards established what actually pulls sharks in: irregular, pulsed, low-frequency sound of the kind a struggling or wounded fish makes. Steady tones do little. Erratic pulses attract sharks from hundreds of metres in open water, which is why spearfishing and a strung catch change the odds so sharply. The way that information is processed is covered in the shark brain.
Claims about shark sounds that do not survive checking
A great deal of what circulates online about this question is invented, and some of it has been repeated so often it reads as established. Three claims are worth naming directly.
The first is that sharks produce low-frequency drumming during courtship, a “boom-boom-boom” audible for miles. There is no published recording of this from any shark. The description is borrowed from bony fish such as drums and croakers, which really do produce it — with the swim bladder sharks do not have. The second is a list of clicks, whistles, bleats and croaks attributed to sharks generally. Only the rig's click has ever been recorded, and whistles in particular require a mechanism no shark possesses.
The third is that sharks emit a defensive pulse when threatened. Nothing in the literature supports it. Sharks under threat have well-documented behavioural displays — the arched back, lowered pectoral fins and stiff swimming of an agonistic reef shark — and those displays are visual, which is precisely the point. A shark warning something off shows it rather than says it. If you want the rest of the sensory picture, start with shark anatomy and how well sharks see.
Frequently asked questions
Do sharks make any sound at all?
One species does. The rig, a small New Zealand houndshark, has been recorded producing sharp clicks while being handled, and that is the only documented case of a shark making a sound deliberately. Every other noise associated with sharks comes from the mechanics of swimming and feeding rather than from any sound-producing organ.
Why can't sharks make noise like other fish?
Noisy bony fish drum on a gas-filled swim bladder using fast sonic muscles. Sharks have no swim bladder, relying instead on a large oily liver and fin lift for buoyancy, and no shark has been found with equivalent sonic musculature. Without a resonating gas chamber there is nothing for a shark to vibrate.
What sound did the rig shark make?
Short, sharp clicks with most of their energy above about 2 kilohertz and source levels around 156 decibels. The pitch sits above the rig's own hearing range. Researchers think the sound comes from the shark's flattened crushing teeth snapping together, and it appeared mainly in the first seconds of handling.
Can sharks hear?
Very well, at low frequencies. Shark hearing covers roughly 10 to 800 hertz and is most sensitive below about 400 hertz. There are no external ears; two small pores on the head lead to an inner ear on each side. Sharks detect irregular low-frequency pulses at considerable distance in open water.
Do sharks roar or growl?
No. Roaring and growling need lungs, a larynx and vocal folds, none of which exist in a shark. Water passes in through the mouth and out through the gill slits without crossing any vibrating membrane. A shark that appears to be roaring in film or television has been given the sound in post-production.
Do sharks communicate with sound?
There is no evidence that they do. Shark social signalling that has been documented is visual and postural: arched backs, dropped pectoral fins, exaggerated swimming and body positioning during courtship or confrontation. Chemical cues and water movement detected by the lateral line carry information too, but no shark is known to signal acoustically.
What noises attract sharks?
Irregular, pulsed, low-frequency sound of the kind a struggling fish produces. Field experiments dating back to the 1960s showed sharks approaching such pulses from hundreds of metres away, while steady tones drew little response. This is the reason spearfishing, a strung catch or a thrashing swimmer changes the risk picture.
Is it true sharks drum during mating?
No. The claim describes something real, but in the wrong animals: drums and croakers genuinely produce courtship drumming using the swim bladder. No published recording exists of any shark doing so, and sharks lack the organ the behaviour depends on. The story appears to be a transfer from bony fish literature.
References
A small team focused on researching sharks and making marine biology easy to understand. Every page is reviewed against current species records and the SharkSider attack database, and updated when new incidents or research appear.
Published March 23, 2023 · Last updated September 23, 2026 · Filed under FAQ.
