Swimming earplugs block sound when they are solid. A solid silicone, foam or mouldable putty plug seals the ear canal and cuts out most of what you would normally hear, while a filtered plug is built to let ambient sound through as it helps keep water out. Those two designs decide whether you hear your coach's whistle, the swimmer coming up behind you, or the safety kayak calling you back on course.
This guide, updated in October 2026, covers the two types, what each one sounds like in the pool, open water and the surf, and how to choose a pair you will keep wearing past the second session.
Do swimming earplugs block sound?
Swimming earplugs fall into two camps, and they behave very differently.
- Solid plugs - moulded silicone, foam, wax or putty. They block water and most sound. Anything that seals the ear canal with solid material works as a noise plug, whether it was sold for the pool or for sleeping.
- Filtered plugs - a seal around the canal with a small acoustic channel or membrane built into the plug. They are designed to help keep water out while ambient sound passes through.
So it depends on the plug. If the packaging doesn't mention a filter, assume it blocks sound.
Why solid earplugs go quiet
Solid earplugs go quiet for the same reason a finger in your ear does. Sound reaches your eardrum through the open ear canal, and a solid plug closes that path. Some sound still gets through the plug and the bones of your skull, but voices turn into murmurs and quieter sounds disappear.
There is a second effect swimmers notice straight away. With the canal sealed, sounds from inside your own body get louder: your breathing, your heartbeat, your own voice, the crunch of your jaw. Audiologists call this the occlusion effect. In the water it is the "head in a bucket" feeling - and it is one of the main reasons people stop wearing earplugs after a couple of sessions.
How filtered earplugs let ambient sound through
Filtered earplugs keep a path open for sound while making it harder for water to follow. The filter is usually a very small channel, a mesh or a water-repelling (hydrophobic) membrane set into the body of the plug. Air-borne sound passes through it. Water's surface tension makes it much harder for water to get through an opening that small, especially one lined with a water-repelling material.
In practice, a filtered plug is quieter than an open ear - you are not hearing exactly what you hear without plugs - but it is a long way from the cut-off silence of a solid plug. Conversations, whistles and the sound of the water stay with you.
SEAR Plugs use this approach: a hydrophobic acoustic pathway designed to help reduce water entry while allowing ambient sound to pass through. How well any filtered plug keeps water out still comes down to fit, which we cover below.
What you hear with each type
The table below is a typical experience with the head above water, not a lab measurement. Fit, the individual plug and your own ears all change the result.
| Sound | Open ears | Filtered plug | Solid plug |
|---|---|---|---|
| Coach or lifeguard on the pool deck | Clear | Clear, slightly quieter | Muffled, easy to miss |
| Start signal or whistle | Clear | Clear | Often faint |
| Lane mate or swimmer coming alongside | Clear | Audible | Easy to miss |
| Safety kayak or boat engine in open water | Clear | Audible | Muffled |
| Your own breathing and voice | Normal | Slightly louder | Much louder (occlusion effect) |
Underwater, everything changes
With your head underwater, plugs make less difference than you might expect. Underwater, much of what you hear reaches the inner ear through the bones of the skull rather than through the ear canal, so the sound is already dull and hard to place, plugs or no plugs.
The moments that matter are the ones with your head up: between lengths, sighting in open water, sitting out the back between sets. That is where a solid plug takes away information and a filtered plug leaves it in place.
Why hearing matters in the pool, open water and surf
Hearing in the water keeps you connected to what is going on around you, and that is a safety issue as much as a comfort one.
In the pool, it is your coach's instructions between reps, the lifeguard's whistle and the swimmer about to overtake. Missing those makes training slower and lane etiquette harder.
In open water, sound fills the gaps your eyes can't cover while you swim. Safety kayaks, marshals, boat engines and other swimmers are all easier to track if you can hear them when you lift your head to sight. Our guide to earplugs for triathletes and open-water training goes deeper on race and training situations.
In the surf, and on a kite or wing, it is the set you hear before you see it, another surfer calling their wave, a board coming loose, a gust building. Solid plugs take all of that away, which is why so many people who ride waves try earplugs and abandon them.
The point of protecting your ears is to spend more time in the water. That only works if the protection doesn't cut you off from it.
Fit decides both the seal and the sound
Fit is what makes any swimming earplug work. A plug that doesn't seat properly lets water in around its edges, and it changes how things sound - a half-seated plug can rustle, whistle or feel blocked on one side.
Ears are rarely a matching pair, so a single size seldom fits both. SEAR Plugs come with four wing sizes and three tip sizes, which create 12 fit combinations, and you can run a different combination in each ear.
A quick fit check on dry land saves a lot of frustration:
- Fit the plug so the tip sits snugly in the canal and the wing rests in the bowl of your outer ear.
- Talk, then listen - with a filtered plug you should still hear a conversation in the room.
- Shake your head, open and close your jaw, and pull your earlobe gently. If a plug moves, try the next wing size up on that ear.
- Test it in the water before a session that matters, not on race day.
Choosing swimming earplugs you will keep wearing
The best swimming earplug is the one you put in every session. A few questions make that choice simpler:
- Do you need to hear? For coached sessions, open water, surf, kite and wing, choose a filtered plug. For solo lengths or a shower, a solid plug may be all you need.
- Will it stay in? Wing-style retention suits flip turns, duck dives and wipeouts better than a plain tip. For active water use, a retention leash keeps the pair together.
- Is it reusable? Silicone plugs last many sessions if you rinse them, let them dry and store them in their case.
- Can you fix the fit? Multiple tip and wing sizes beat a one-size plug for almost everyone.
Why wear earplugs at all? Keeping water out of the ear canal is part of standard prevention advice for swimmer's ear (otitis externa) - the NHS guidance on outer ear infections suggests earplugs or a swimming hat over your ears when you swim. If you want a fuller rundown of plug types and materials, our guide to how swimming earplugs work and how to choose them covers it.
If you swim in a pool, the sea or open water and want to keep hearing what is around you, see how SEAR's earplugs for swimming are sized and set up.
FAQ
Can you hear with swimming earplugs in?
You can hear with filtered swimming earplugs in - voices, whistles and the sound of the water still come through, a little quieter than with open ears. With solid silicone, foam or putty plugs you hear much less, and your own breathing and voice sound louder.
Can I hear my coach with earplugs in?
With filtered earplugs, most swimmers can hear a coach on the pool deck when their head is above water. With solid plugs, instructions are easy to miss unless the coach is close and loud.
Are filtered earplugs still waterproof?
No earplug can guarantee a completely dry ear. Filtered plugs are designed to help keep water out of the ear canal, and how well they do that depends mostly on fit. A well-fitted filtered plug and a badly fitted solid plug can perform very differently from what the packaging suggests.
Do earplugs affect your balance?
Earplugs sit in the outer ear canal; your balance organs are in the inner ear, and a well-fitted plug doesn't touch them. Some people feel brief dizziness when cold water hits the ear canal, and keeping water out is one reason they give for wearing plugs. If you have ongoing dizziness, see a doctor.
Is it safe to swim in open water with earplugs?
Many open-water swimmers wear earplugs. The safety question is mostly about hearing: a filtered plug lets you keep track of safety boats, marshals and other swimmers, while a solid plug can cut you off. Follow your event's or venue's safety briefing, and if you have an ear condition, check with a doctor first.
