Ear Defenders: Which SNR You Need, What to Buy, and Why Your ANC Headphones Won't Cut It

An angle grinder cutting through a steel lintel produces 105-110 dB of noise. That's louder than a chainsaw. Ten minutes of it is enough to cause permanent hearing damage. And here's the thing about hearing loss: you won't notice it happening. It accumulates over weeks and months of "quick cuts" and "just a minute without protection" until one day you realise you can't follow conversations in a noisy pub, or a persistent ringing in your ears won't stop. It never stops. Hearing damage is irreversible.

A pair of ear defenders costs less than a sandwich. There is no rational reason to skip them.

What they are and when you need them

Ear defenders (also called ear muffs) are over-ear cups lined with acoustic foam, held together by a sprung headband. They work by creating a sealed chamber around each ear that blocks airborne noise. The foam absorbs sound energy, the rigid cup reflects it, and the cushioned seal against your head prevents it leaking in around the edges.

You need them any time you're near a power tool. When you're operating one, obviously, but also when anyone within a few metres is using one. Sound intensity drops with distance, but an angle grinder at 110 dB is still above 85 dB at five metres.

How loud are the tools you'll encounter on a build? Louder than you think.

Tool	Typical noise level
SDS drill into masonry	95-105 dB
Circular saw	100-110 dB
Mitre saw	100-108 dB
Angle grinder (cutting steel)	105-115 dB
Nail gun	~100 dB
Hammer drill	95-100 dB

Every one of those exceeds 85 dB. Every one requires ear defenders.

Understanding SNR ratings

Every pair of ear defenders sold in the UK carries an SNR number. SNR stands for Single Number Rating, and it tells you how many decibels of noise the defenders block under laboratory conditions. An SNR of 30 means they reduce noise by 30 dB in a controlled test.

The catch: real-world performance is lower than the lab number. Hair, glasses, a loose fit, head movement, sweat breaking the seal. The HSE (Health and Safety Executive) recommends subtracting 4 dB from the advertised SNR to estimate what you'll actually get. This is called derating.

The HSE publishes a simple table for matching SNR to noise level:

Noise level at your ear	SNR you need
85-90 dB	20 or less
90-95 dB	20-30
95-100 dB	25-35
100-105 dB	30+

For most power tool work on an extension site, SNR 25-30 covers the majority of situations. If you're cutting steel with an angle grinder or working next to one, go for SNR 30+.

There's an important nuance here: more is not always better. The HSE explicitly warns against overprotection. Ear defenders that reduce noise below 70 dB at your ear isolate you from warning shouts, vehicle reversing alarms, and the sounds of structural creaking that experienced builders listen for instinctively. If you're working in a 90 dB environment, SNR 37 defenders (derated to 33 dB real-world) push you down to 57 dB. That's too quiet. You can't hear someone yelling "watch out." Match the SNR to the noise level, don't just buy the highest number.

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Types of ear defenders

Passive ear defenders

The standard type. No batteries, no electronics, no moving parts. Two foam-lined cups on a headband. They work by physically blocking sound. This is what you should buy for DIY and site management work.

Within passive defenders, the main differences are headband style and SNR rating.

Headband (over-the-head) is the most common style. Highest clamping force, best seal, highest SNR ratings. The downside: they don't fit over a hard hat.

Neckband (behind-the-head) loops behind your neck instead of over the top. Lower clamping force and slightly reduced SNR compared to headband versions of the same model. But they work with hard hats, which makes them essential for site work where you need both.

Helmet-mounted defenders clip directly onto hard hat accessory slots. Convenient because they flip up when you don't need them and you can't lose them. But the attachment mechanism reduces clamping force, so attenuation is lower than the equivalent headband model due to the reduced clamping force.

Foldable versions collapse flat for storage. Handy if you keep a pair in a toolbox or van glovebox. The folding mechanism is a potential weak point over time, but modern designs (JSP Sonis Compact, 3M Peltor Optime series) are reliable.

Electronic (level-dependent) ear defenders

These use microphones and speakers to boost quiet sounds (speech, warning signals) while instantly cutting loud impulse noise. They're popular with shooters and on large commercial sites where communication matters.

For a homeowner managing an extension, they're overkill. You're not coordinating a team of twenty by radio. Passive defenders at SNR 30+ do the job for a tenth of the price. If you do find yourself working alongside trades frequently and struggling to communicate, electronic defenders start around £100 – £160 but a simpler solution is to take the defenders off briefly when you need to talk, then put them back on.

Earplugs (the alternative)

Disposable foam earplugs cost about 20-25p per pair. You roll them between your fingers, insert them into the ear canal, and they expand to create a seal. SNR ratings of 32-37 dB are common, often higher than ear defenders.

The drawbacks: they're fiddly to insert correctly (most people under-insert them, halving the protection), they're not great if you're taking them in and out repeatedly, and some people find them uncomfortable for long periods. They're excellent as a backup pair kept in your toolbox pocket. Not ideal as your primary protection.

Wearing them properly

Getting this wrong is common. The HSE's 2024-2025 enforcement campaign found that 63% of workers on inspected sites hadn't been told that ear protection must be worn continuously during noise exposure. Taking them off "just for a minute" to hear something defeats the purpose. Even brief unprotected exposure in a noisy environment adds up.

Full seal, every time. The cups must sit flat against the side of your head with no gaps. Hair caught under the cushion, thick-armed safety glasses, a hood bunched up underneath, all of these break the seal and can reduce protection by 5-10 dB.

Glasses are a real problem. The arms of safety spectacles create a channel between the cushion and your skin. This can reduce attenuation by anywhere from 1 to 10 dB depending on the frame thickness. Three solutions: switch to strap-style safety goggles that sit flush under the cups; buy ear defenders with gel cushions (they conform better around glasses arms); or switch to earplugs when you need to wear glasses for extended noisy work.

Adjust the headband. The cups should sit centred over your ears with even pressure on both sides. Too tight causes headaches after thirty minutes. Too loose allows gaps. Most headbands are adjustable by sliding the cups up or down on the band.

Checking your ear defenders

Cushion condition. The foam cushions should be soft and springy, not flattened, cracked, or hardened. Press them with your thumb. If they don't bounce back quickly, or the vinyl covering is split, the seal is compromised. Replacement cushions are available for most branded models (3M Peltor, JSP Sonis) at £5 – £10 per pair.

Headband tension. The band should hold the cups firmly against your head without you holding them. If the band has lost its spring and the cups hang loosely, the defenders aren't sealing properly. Replace them.

Hygiene. Wipe the cushions with a damp cloth and mild soap after each use session. No solvents, no alcohol wipes on the cushion material. Sweat and site dust degrade the vinyl faster than you'd expect. Replace cushions every 6 months with regular use, every 3-4 months in hot or dusty conditions.

What to buy

The community consensus across every UK trade forum is clear: the 3M Peltor Optime III is the default recommendation for construction work. SNR 35 dB, comfortable for extended wear, durable enough to last years with cushion replacements, and available everywhere. Mid-range in price but top-tier in reputation.

But you don't necessarily need to spend that much.

For most homeowners managing an extension, the decision is straightforward. If you'll be on site during angle grinding, steel cutting, or demolition work, buy the 3M Peltor Optime III or JSP Sonis 3. If your site visits mostly coincide with quieter phases (plastering, second fix), a budget pair at SNR 27+ is adequate.

Keep a pack of disposable foam earplugs in your toolbox as backup. A 5-pack of 3M Classic earplugs costs about £2 from Toolstation. Moldex Pura-Fit or Howard Leight Laser Lite are the go-to disposable plugs if you want to buy in bulk (50-pair tub for around £14).

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Hard hat compatibility. If you need ear defenders and a hard hat simultaneously (and you will, during structure and roof phases), you have two options. Neckband versions of the Peltor Optime range (around £24 – £31 at Screwfix) loop behind your head and fit under any hard hat. Or helmet-mounted defenders clip directly to compatible hard hats via accessory slots. The JSP Sonis 1 helmet-mounted (SNR 26, around £23) fits JSP EVO series hard hats. Check compatibility before buying. Not all hard hats accept all helmet-mounted defenders.

Where you'll need this

Ear defenders are needed during the noisiest phases of any extension or renovation project:

• Skip hire and site setup - hearing protection when using SDS breakers and demolition tools
• Walls and blockwork - angle grinder cutting bricks and blocks generates 100-110 dB
• Steels and lintels - cutting steel with an angle grinder is one of the loudest operations on a residential site
• Roof structure - circular saws, mitre saws, and nail guns running for extended periods

Keep a pair hanging on a nail by the site entrance. The ones sitting in your van glovebox don't protect your hearing.