⏱️ Estimated reading time: 12 min
Key Takeaways
Passive earplugs make everything roughly 24 dB quieter, the alarm included. An alarm designed to sit above the site’s background noise keeps that margin at the ear, so it stays audible because it is loud, not because a filter passes it through. Your employer should confirm it with a listening test.
BS 5839-1, the British Standard for workplace fire alarms, recommends at least 65 dB(A), or 5 dB(A) above any background noise that lasts more than 30 seconds. UK government fire guidance adds visual alarms where people wear hearing protectors.
Most passive earplugs block high frequencies more than low ones. Our WorkPRO earplugs are rated H 24, M 21 and L 19 dB, rising to about 35 dB at 8 kHz, so high-pitched sounds lose the most.
HSE calls it over-protection when a protector brings the level at the ear below 70 dB(A). It can leave workers isolated and tempt them to pull their plugs out, so HSE suggests aiming for 70 to 80 dB(A).
It can be, provided the horn and reversing alarm are chosen to stand out over the aisle noise with hearing protection taken into account. A listening test with plugs fitted is the check, and visual warnings help where noise is high.
Keep the protection in and tell your supervisor. Ask for a listening test, visual alarms or a different protector, such as a lower rating or a level-dependent model.
Can you hear alarms with earplugs in at work? Passive earplugs make everything roughly 24 dB quieter, the alarm included. A 95 dB(A) site becomes about 75 dB(A) at the ear (95 − 24 + 4 for real-world fit), and an alarm designed to be louder than the background stays audible because it is loud, not because a filter passes it through.
Whether it catches your attention on your site is a separate question, and your employer should answer it with a listening test. Few do. In HSE’s latest inspection campaign, 95% of employers had not checked whether workers wearing hearing protection could still detect warning signals such as fire alarms and reversing alerts.
On safety forums, the worry often starts with a forklift trainer telling a new starter that plugs are dangerous because they won’t hear the other trucks. The honest answer sits in the physics and in HSE’s guidance, and bare ears are not part of it.
At Bollsen, we are a hearing protection brand trusted by 1,000,000+ people, and we make reusable earplugs for work, sleep, music and travel. Our WorkPRO earplugs are passive, so we use their published test numbers as the worked example. Our workplace hub covers noise levels, fit, UK rules and the full range of earplugs for work alongside guides for each trade.
What does a passive earplug do to an alarm?
A passive earplug lowers every sound that reaches the ear, the background noise and the alarm alike, by roughly its rated amount, so the gap between the two stays about the same while the overall level drops to something safer for a full shift. Everything is simply quieter.
The drop is not even across pitches. HSE’s L108 guidance on controlling noise at work notes that most protectors give more attenuation at high frequencies than at low, which makes sounds muffled and reduces the clarity of speech. That is the “underwater” feeling forum users describe after their first shift with plugs in.
WorkPRO follows that pattern. It is rated SNR 24 dB with H 24, M 21 and L 19 under EN 352-2, and its measured attenuation runs from 22.1 dB at 500 Hz and 23.2 dB at 1 kHz up to 28.4 dB at 2 kHz, 29.3 dB at 4 kHz and 35.3 dB at 8 kHz. BS 5839-1 prefers fire alarm tones of 500–1,000 Hz, while a high-pitched beep at 2–4 kHz loses a few decibels more.
How loud are workplace fire alarms designed to be?
BS 5839-1, the British Standard for workplace fire alarms, recommends a sound level of at least 65 dB(A), or 5 dB(A) above any background noise likely to last more than 30 seconds, whichever is greater, up to a maximum of 120 dB(A). It is designed against the site’s own noise, not silence.
Other danger signals follow a separate standard. Under BS EN ISO 7731, danger signals for work areas are typically set more than 15 dB above the background noise, and L108 says warning signals should be chosen with any hearing protection taken into account. Because a passive plug lowers the signal and the background together, a fire alarm 5 dB(A) above the background is still roughly 5 dB(A) above it at the ear, and a 15 dB margin stays roughly 15 dB.
A 5 dB(A) margin is thin, which is why the government’s fire safety risk assessment guide for factories and warehouses says that where background noise is high or people wear hearing protectors, the audible warning should be supplemented, for example with visual alarms. BS 5839-1 has its own section on visual alarm signals.
Anyone choosing earplugs for construction workers faces the same question with klaxons and plant horns. Our guide to earplugs for construction workers matches protection to each trade’s noise levels, with site warnings in the plan.
What does an SNR 24 earplug leave at your ear on a typical site?
With HSE’s 4 dB real-world allowance, an SNR 24 dB earplug leaves roughly the site level minus 20 dB at the ear, so a 90–95 dB(A) machine shop comes down to about 70–75 dB(A), inside HSE’s 70–80 dB(A) target, while quieter areas drop below the 70 dB(A) floor. Levels are typical, not measured on your site.
| Site sound | Typical level | At the ear with SNR 24 (level − 24 + 4) | HSE band (suggested SNR) | What it means |
|---|---|---|---|---|
| Packing hall or warehouse floor | 80–85 dB(A) | about 60–65 dB(A) | Below 85: protection offered from 80, not enforced | Under HSE’s 70 floor, so over-protection; a lower rating fits better |
| Forklift aisle | 85–90 dB(A) | about 65–70 dB(A) | 85–90: SNR 20 or less | At or under the floor; over-protection risk |
| Machine shop or factory floor | 90–95 dB(A) | about 70–75 dB(A) | 90–95: SNR 20–30 | Inside HSE’s 70–80 dB(A) window |
| Angle grinder or circular saw | 95–100 dB(A) | about 75–80 dB(A) | 95–100: SNR 25–35 (SNR 24 sits just under) | Top of the window; check the fit |
| Breaker or concrete saw | 100–105 dB(A) | about 80–85 dB(A) | 100–105: SNR 30 or more | Not enough alone; wear under ear defenders |
A fire alarm designed to BS 5839-1 sits at least 5 dB(A) above persistent background noise in every row, so it keeps roughly that margin at the ear. Impulse noise falls outside this table. For when muffs suit the job better than plugs, see our comparison of earplugs vs ear defenders at work.
Picking the rating itself is the classic “how much hearing protection do I need” question, and it has its own guide. Our walkthrough on how much hearing protection do I need sets out HSE’s SNR bands and the HML method; this article stays with warning sounds and awareness.
What is over-protection and why does it matter?
Over-protection means a protector brings the level at the ear below 70 dB(A). L108 tells employers to aim for 70 to 80 dB(A) and to avoid going lower, because it can cause safety risks through an inability to hear nearby traffic or warning sound signals, along with communication difficulties and a sense of isolation.
The second risk is behavioural. HSE’s hearing protection guidance warns that over-protection can lead to an unwillingness to wear protectors, and forum posts bear it out: if they can’t hear anything, people take the plugs out to talk. A plug in a pocket protects nothing during the next burst of noise.
The answer is a lower rating for the quieter area, not bare ears. In an 85 dB(A) packing hall, an SNR 24 plug leaves about 65 dB(A) at the ear, so HSE’s band for 85–90 dB(A), SNR 20 or less, is the better match. Comfort over long shifts is covered in our piece on wearing earplugs all day at work.
How do you know you can hear the alarm on your site?
Under Regulation 5 of the Control of Noise at Work Regulations 2005, the employer’s risk assessment must consider how noise interacts with audible warning signals. L108 adds that simple in-situ listening tests can be the most effective way to confirm workers can pick out the alarms that matter.
HSE sets a high bar. Catching an alarm while you are listening out for it is not enough; it has to grab your attention over the background noise while you work. That means testing during a normal shift, with protectors fitted, where people actually stand.
Forklift aisles deserve their own check, because L108 asks for particular care around mobile machinery and traffic. Horns and reversing alarms should be tested with the plugs people actually wear, a point we return to in earplugs for warehouse workers.
If you can’t pick out an alarm with your plugs in, keep them in and tell your supervisor. Ask for a listening test and, where needed, visual beacons, a different protector or a change to how warnings are given. HSE’s CUFF check (Condition, Use, Fit the ear, Fit for purpose) is a handy prompt for that conversation.
When are level-dependent electronics the right answer?
Level-dependent (sound-restoration) protectors use a microphone and speaker to relay outside sound when it is quiet and switch to full attenuation when it gets loud. L108 says they suit work where noise is intermittent and communication matters in the quieter spells.
They make sense when a role depends on radio contact, when loud bursts alternate with long quiet stretches, or when a listening test shows a passive plug leaves a key signal too faint. Each type still needs a listening check, because electronics change how sound arrives, not the employer’s duty to test it.
WorkPRO is passive, so it isn’t the tool for those roles. Our guide to noise cancelling earplugs for work covers the electronic options.
Where do WorkPRO earplugs fit in?
WorkPRO suits steady noise in the 90–95 dB(A) band, where its SNR 24 dB rating (H 24, M 21, L 19, tested to EN 352-2) brings the ear to about 70–75 dB(A), inside HSE’s window. Its low profile lets ear defenders go over the top above 100 dB(A).
It reduces everything, alarms and voices included. A loud warning stays audible because it is loud, not because a filter passes it through.
For steady workshop and factory noise around 90–95 dB(A), our WorkPRO earplugs (SNR 24 dB, £29.95) are reusable hypoallergenic silicone plugs with a patented design in high-visibility yellow, German-tested, independently certified 24 dB. They are one part of your employer’s noise plan, never a substitute for testing the alarms.
So, can you hear alarms with earplugs in at work?
On a well-designed site, a passive plug turns the alarm down with everything else, and the alarm’s margin over the background carries through to the ear. That only holds when the employer has chosen alarms with protection in mind and checked them with a listening test.
Pick a rating that lands you between 70 and 80 dB(A), speak up when a warning gets lost, and treat electronics as the answer for radio-heavy or stop-start work. Riders ask about hearing traffic with earplugs in, and our motorcycle guide to hearing traffic with earplugs in covers the same question for road riding.
His connection to hearing protection stems from personal experience with sound sensitivity during live events and work in noisy environments, an issue that made him more aware of the long-term risks of unmanaged noise exposure. Today, as both a communicator and a user of BOLLSEN products, he is passionate about raising awareness around the importance of proactive hearing care.
At BOLLSEN, he develops data-driven marketing campaigns, writes SEO-focused articles, and manages communication channels that connect customers with practical knowledge about hearing protection. His work ensures that BOLLSEN’s message—prioritizing health, performance, and sustainability reaches a global audience in an engaging and trustworthy way.
Passionate about writing since childhood, Timotej combines creativity with a strong analytical approach, continuously testing new ideas in digital marketing, performance advertising, and social media. He believes in learning through innovation and collaboration, balancing leadership with openness to new perspectives.
Beyond his professional role, Timotej is committed to a healthy lifestyle and finds inspiration in fitness, sports, and quality time with friends. His personal passion for well-being aligns with BOLLSEN’s core values, making his work not only a career but also a cause he deeply believes in.