Phoenix Journal · LEV Testing
Noise-induced hearing loss is permanent, and it rarely arrives with a bang - it builds quietly around extraction fans, plant rooms and busy kitchens until the damage is done. Knowing the action values, and measuring against them, is how you catch it in time.
The head chef never thought of the kitchen as a noisy place - not really.
Loud, yes, on a Saturday service. But he had worked in it for eleven years, and somewhere along the way he stopped noticing the roar of the extraction canopy, the whine of the make-up air fan, the clatter of pass and dishwash. It was only when his wife started complaining that the television was too loud, and he found himself nodding along in meetings without quite catching the words, that he wondered whether the room had been doing something to him all along. It had. And the frustrating thing about noise-induced hearing loss is that by the time you can measure it in yourself, it is already permanent.
Hearing damage from work is one of the most common occupational conditions in the country, and one of the most preventable. You cannot see it building. There is no bruise, no ache the next morning that tells you to ease off. The only honest way to know whether a space is putting hearing at risk is to measure it against the numbers the law already sets out - and then to act on what the measurement tells you.
How the damage happens
The ear is a remarkable instrument, but it is not built for a working lifetime of mechanical noise. Sound reaches tiny hair cells deep in the inner ear, and sustained exposure to high levels gradually wears those cells down. They do not grow back. That is the hard fact at the centre of the whole subject - noise-induced hearing loss is cumulative and irreversible, and it usually takes the high frequencies first, which is exactly why speech starts to sound muffled while background rumble seems as loud as ever.
Part of the problem is that the body adapts. Spend eight hours a day beside a running fan and your brain simply filters the drone out. You genuinely stop hearing it. That habituation feels like comfort, but it is doing nothing to protect the hair cells underneath - it only removes the discomfort that might otherwise prompt you to turn something down or step away. Tinnitus, that persistent ringing or hissing in a quiet room, is often the first sign a person actually notices, and it frequently arrives alongside loss that has been developing for years. A useful rule of thumb from the regulators is this - if you have to raise your voice to hold a normal conversation about two metres from someone, the noise is likely at a level worth assessing.
Commercial kitchens rarely feel like heavy industry, so they get overlooked. Yet a busy restaurant floor commonly sits around 80 dB(A), and the mechanical side - extraction canopies, make-up air units, refrigeration plant and dishwash - stacks on top of that. Larger exhaust fans can run in the region of 68 to 75 dB(A) at close quarters before you add a single pan to the stove. None of it sounds dramatic on its own. Combined, across a long shift, it is more than enough to matter. Here is what tends to push a kitchen or plant space into the risk zone:
That last point is worth dwelling on, because an extraction system that is not moving air properly does not just perform badly - it works harder and adds to the noise burden. If you have ever noticed the system labouring in rough weather, it is worth understanding why extraction can perform worse on windy days, since a struggling fan is often a louder one too.
What the law asks of you
The framework in Great Britain is the Control of Noise at Work Regulations 2005, which came into force in April 2006. It replaced older rules and, importantly, lowered the levels at which an employer has to step in. The Regulations do not simply say "keep it quiet" - they set specific daily exposure figures, and at each one a clear duty is triggered. The point is to turn a vague worry into something you can actually measure and act upon.
There are three thresholds worth committing to memory, each expressed as a daily or weekly average exposure with a separate peak figure for sudden, sharp sounds. Get these straight and the whole subject becomes far less abstract:
Above the upper action value you also owe workers health surveillance - regular hearing checks - so that any loss is caught early and the person moved away from harm before it worsens. Reaching for ear defenders is the last line, not the first. The Regulations expect you to design the noise out where you can - quieter fans, better bearings, acoustic treatment, silencers on ductwork, enclosure of plant - before you rely on someone remembering to wear protection every hour of every shift.
The thread running through all of this is measurement. You cannot manage what you have not measured, and a person’s impression of "a bit loud" is no basis for a legal duty either way. A competent noise assessment establishes the real daily exposure for each role, accounts for how long people spend near each source, and tells you plainly which action values are in play. That is also where good building services and hearing protection meet - the engineers who understand your extraction and ventilation plant are the ones who can advise on running it quieter, and controlling noise at the fan is almost always kinder than fighting it at the ear. For workshop and back-of-house settings, there are practical, ordinary steps that make a real difference to reducing noise exposure in a workshop without shutting the place down.
None of this needs to be daunting. The Regulations hand you a clear ladder of numbers and a clear set of responses. Measure honestly, act on what you find, keep the plant maintained so it does not drift louder over the years, and you protect something your team can never get back once it is gone.
Questions
Under the Control of Noise at Work Regulations 2005, you must make hearing protection available once daily exposure reaches the lower action value of 80 dB(A). At the upper action value of 85 dB(A) you must go further - reduce exposure so far as is reasonably practicable, mark hearing protection zones, and ensure protection is actually worn. The absolute exposure limit value, which must never be exceeded, is 87 dB(A) taking any protection into account.
No. The damage happens to hair cells in the inner ear, and those cells do not regenerate, so the loss is permanent and cumulative. This is exactly why early measurement and prevention matter so much - once you can detect the loss in yourself, the harm is already done. Health surveillance above the upper action value exists to catch changes early and move people away from harm before it worsens.
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