Do Fish Hear? Ears Without Eardrums, the Lateral Line, and What Scares Them

Do fish hear? Yes. Every fish has a pair of inner ears inside its skull, just behind the eyes, and some hear far better than you would guess. What no fish has is an ear hole or an eardrum. It does not need one: a fish’s body is about as dense as water, so sound passes straight through it and the ear reads the vibration from the inside (Popper and Hawkins 2019). Below: how the fish ear works, how well bass, carp and catfish hear, whether your voice reaches them, and which noises send fish running.

In a hearing test, a brown bullhead picked up a whistle from 65 m (213 ft) away. Your voice, meanwhile, loses about 99.9% of its energy at the surface before it ever gets wet.

Do fish have ears? Yes, but on the inside

Look at a bass and you will not find an ear. It is there, one on each side of the skull. Inside each ear sit three small, hard lumps called otoliths, or ear stones, each resting on a bed of hair cells. When a sound wave passes, the whole fish moves with the water, but the heavier stone lags a fraction behind. That tiny lag bends the hair cells, and the bending is what the fish hears (DOSITS; Popper and Hawkins 2019).

The ear stones do a second job. They grow a new ring every year, like a tree trunk, so a biologist can slice one and count a fish’s birthdays. NOAA ages about 40,000 otoliths a year in Alaska alone (NOAA Fisheries). A fish carries its age inside its head.

Do fish have eardrums? No, and they do not need one

You have an eardrum because you live in air. Air is thin and your body is thick, so sound has to be caught by a membrane and passed inward. A fish is made mostly of water and lives in it. Sound goes through it as if it were not there, so the fish ear reads particle motion, the back-and-forth wiggle of the water itself (Popper and Hawkins 2018).

Some fish added a drum anyway, on the inside. The swim bladder, the air-filled balloon a fish floats with, pulses with every sound wave. In carp, goldfish, minnows and catfish, a chain of tiny bones called the Weberian ossicles links that bladder to the inner ear (Ladich 2023). It turns the swim bladder into an eardrum and lets these fish hear notes ten times higher than a bass can.

How well do fish hear? Bass and trout against carp and catfish

Fish fall into two camps. The generalists, with an inner ear and nothing more, hear the low end of the world. Bass, trout, walleye, pike and perch pick up sounds from below 50 Hz to about 300–500 Hz. A largemouth hears best around 100 Hz and nothing above about 600 Hz (IGFA 2021). Atlantic salmon hear from 100 to 380 Hz (Hawkins and Johnstone 1978). For these fish the world is thuds, rumbles and hums. A whistle does not exist.

The specialists, with the Weberian ossicles, hear to 3–5 kHz: a reel’s click, a lure’s rattle, the splash of a small bait. The bullhead that heard the whistle at 65 m (213 ft) is a catfish, and every catfish shares the same bone chain (Ladich 2023).

Ranges from Popper and Hawkins (2019), IGFA (2021), Hawkins and Johnstone (1978) and Ladich (2023). The last column follows from those ranges; nobody has run a scare test on each species.

The lateral line: hearing with the whole body

Fish have a second sense of hearing that you do not. Along each flank runs a line of tiny pores with more hair cells beneath them. This lateral line feels water moving at 4 to 200 Hz, but only close by, within roughly a body length (DOSITS). Scientists call it distance touch. It is how a bass feels a minnow flick its tail in muddy water at night, and how a school turns as one fish.

It also stays switched on. A resting fish ignores a leaf drifting past, yet reacts the moment something lands within reach. Your lure works the same way: a wobbling crankbait pushes water, and a fish that cannot see it feels it coming.

Can fish hear you talk? Almost not at all

Sound in water travels about 4.3 times faster than in air, roughly 1,500 m/s (4,900 ft/s) against 340 m/s (1,100 ft/s), and it carries a long way (NOAA Ocean Service). That sounds like bad news for anyone who talks on the bank. It is not, because the surface acts as a wall. When a sound wave in air hits water, about 0.1% of its energy passes through; the rest bounces back up (sound transmission study, 2012). Your voice, the radio, a kid’s laugh: fish get almost none of it.

What does get in is anything that skips the wall by touching the ground or the boat. Footsteps travel through the soil into the water. A tackle box dropped on the deck, a wave slapping the hull, a trolling motor’s prop: all are made in the water or in something joined to it. They go straight in, right in the thud range every fish hears best.

So the ten-year-old’s version is this: yelling at the fish does not scare it. Stomping toward it does.

The angler’s part: what to keep quiet and what to forget about

1. Walk softly, and stop short of the edge. Step on grass rather than gravel, set heels down slowly, and make the first casts from a few steps back. The ground carries every footfall into the shallows.
2. Wade like a heron. In a trout stream, a boot scraped over rock is a bell to every fish downstream. Slide the foot forward and settle it before the next step.
3. Pad the boat. Carpet or foam on the deck, pliers in a pocket, the tackle box lid closed with a hand, not a bang. A dropped box is the loudest thing on the lake.
4. Ease the anchor down and kill the hull slap. Lower the anchor, never toss it. Drift or run the trolling motor on its lowest speed for the last stretch; a prop is heard, a drifting hull is not.
5. Leave the sonar on. A fish finder pings far above the top of even a catfish’s range, so the picture is free. It is the motor that fish notice, not the ping.
6. Talk, sing, tell the story again. With 0.1% of your voice crossing the surface, conversation costs you nothing. Save the shushing for feet and gear.
7. Match the noise to the fish. Bass barely hear a rattle; carp and catfish hear it loud and clear.

Rattles, carp and catfish: the fish that hear a lure

A lipless crankbait’s rattle chamber shakes metal balls at a pitch near or above the top of a bass’s hearing. What the bass gets is the low pulse of the lure’s body and the pressure wave on its lateral line. Fish it for those, and do not worry that it is too loud.

A carp is different. It hears to 3–5 kHz, and a rattle, a reel’s click or a lead splashing down all land inside that range. Carp anglers lower rigs gently and sit still for a reason. A catfish that can hear a whistle from 65 m (213 ft) certainly hears your sinker hit bottom. Whether that thud calls it in or sends it off, nobody has tested. What is certain is that it heard you arrive.

More of the ways fish sense the world, with a number behind each one, are in the fish facts collection.