Noise Control Measures: The UK Hierarchy and How to Apply It

You have done the assessment. The exposure figures show workers above the lower or upper action values. Now the regulations require you to do something about it — and "give everyone ear defenders" is not the answer the law accepts.

The Control of Noise at Work Regulations 2005 set a clear order of priority for noise control measures. Hearing protection is the last layer, not the first. This guide covers what the hierarchy of controls actually requires, how to choose between control options, and how to document the decisions in a way that holds up under HSE inspection.

This guide covers post-assessment noise control under UK regulations. It is not legal advice. Where exposure is complex or close to limit values, get input from a competent acoustic engineer or occupational hygienist on which engineering controls are reasonably practicable for your workplace.

What the regulations actually require

Regulation 6 of the Control of Noise at Work Regulations 2005 sets two duties when exposure exceeds an action value:

1. Reduce noise exposure to as low a level as is reasonably practicable by establishing and implementing a programme of organisational and technical measures.
2. Use hearing protection (mandatory at upper action value, available at lower action value) — but only as part of the programme, not as a substitute for it.

The phrase "reasonably practicable" is the load-bearing one. It does not mean "do whatever is easiest" — it means weighing the cost, time, and disruption of a control against the size of the noise reduction it produces. A control that would cut exposure by 5 dB(A) for £500 per worker is almost always reasonably practicable. A control that would cut exposure by 1 dB(A) for £20,000 with major production downtime is probably not.

HSE's L108: Controlling Noise at Work (3rd edition) is the authoritative guidance. It expects you to follow a hierarchy — addressing noise at source first, then along the path, then at the receiver — before relying on personal protection.

The control hierarchy explained

The hierarchy follows the same structure as broader health and safety risk control: eliminate the hazard if you can, reduce it if you can't, isolate workers from it, and only then issue PPE. For noise specifically, that breaks into five layers.

1. Elimination — remove the noise source

The strongest control is making the noise stop existing. Practical examples:

• Replacing a high-noise process with a quieter one (e.g., welding instead of riveting, hydraulic instead of pneumatic actuation)
• Removing redundant equipment that runs without producing useful output
• Eliminating impact processes by changing materials or fixings (welded joints instead of bolted, soft-seated valves instead of metal-on-metal)

Elimination is rare in established workplaces because it usually means redesigning a process. Where you can do it during equipment replacement cycles or capital projects, it is the most cost-effective long-term control.

2. Substitution — replace the source with a quieter version

Where elimination is not possible, substitution often is — and it is the most common high-value control in SME workshops.

• Quieter equipment at procurement — when buying new tools, machines, or compressors, specify a maximum sound power level in the purchase order. Manufacturers must declare noise emission figures under the Supply of Machinery (Safety) Regulations 2008, so the data is available before you buy.
• Lower-noise processes — pneumatic tools replaced with electric, percussive drills replaced with rotary, traditional grinding wheels replaced with diamond-tipped equivalents.
• Material changes — softer hose lines reduce air-pressure noise, plastic-coated chains run quieter than bare steel, vibration-damped surfaces reduce ringing.

Substitution typically delivers 5-15 dB(A) reductions and is the area where buying decisions have the longest-running compliance impact. A workshop that bought 90 dB(A) compressors a decade ago is locked into that exposure profile until the equipment is replaced.

3. Engineering controls — reduce noise at source or in the path

Engineering controls modify equipment or the workspace to reduce sound power or block its travel. These are technical measures — they survive worker turnover, do not require ongoing compliance from individuals, and address noise at the cause.

At source:

• Damping — adding mass-loaded vinyl, vibration-damping pads, or constrained-layer damping to vibrating panels (machine guards, bin walls, sheet metal work)
• Isolation — anti-vibration mounts under machinery to stop structure-borne noise transmitting into floors and walls
• Silencers — fitted to compressed-air exhausts, vacuum systems, and engine intakes; can deliver 15-25 dB(A) reductions on point sources
• Lubrication and maintenance — bearings, gearboxes, and conveyor rollers that are worn or under-lubricated produce significantly more noise than well-maintained equivalents. A maintenance schedule is itself a noise control.

In the path:

• Enclosures — fully or partially enclosing a noise source (compressor cabinets, machine guarding with acoustic lining, partial screens)
• Acoustic absorption — adding sound-absorbent material to walls and ceilings reduces reverberant build-up in workshops; particularly effective in metal-walled industrial units
• Distance — relocating noise sources further from worker stations; sound pressure drops by 6 dB(A) for each doubling of distance from a point source in free field

Engineering controls usually deliver the largest reductions per pound spent in established workplaces. They are also the controls HSE inspectors expect to see considered first when reviewing your action plan.

4. Administrative controls — limit exposure through how work is organised

When source and path controls have been applied to the limit of what is reasonably practicable, administrative controls reduce the time individual workers spend exposed.

• Job rotation — workers move between high-noise and low-noise tasks during the shift, reducing daily exposure
• Quiet zones / quiet refuges — break areas located away from noise sources, where workers can rest without ongoing exposure
• Scheduling noisy work — running the loudest processes when fewer workers are present (early morning, late shift, or batched into specific time windows)
• Limiting unnecessary exposure — only operators of a noisy machine should be in its immediate vicinity, not workers who could carry out their tasks elsewhere
• Maintenance and clean-down — operating noisy equipment only when actually needed (not running compressors all day if they are only used in bursts)

Administrative controls have a known weakness: they depend on supervisors and workers actually following the system. Rotation schedules slip when production is pressured. Quiet zones get used as overflow storage. The compliance trail for administrative controls is therefore as important as the control itself — without records, you cannot prove the measure was in force when an inspector asks.

5. Personal hearing protection — the last layer

Hearing protection is required at the upper exposure action value (85 dB(A) daily) and must be available at the lower exposure action value (80 dB(A) daily). It is also the control most workplaces over-rely on.

The regulations expect hearing protection to fill the gap that source and path controls cannot close — not to substitute for them. If your assessment shows 92 dB(A) at a workstation and your only control is "issue ear defenders," you have not met Regulation 6. You have to demonstrate that you considered and ruled out (or applied) elimination, substitution, engineering, and administrative controls first, and that hearing protection is the residual measure.

For practical guidance on choosing the right hearing protection, SNR ratings, comfort, and fit are covered separately in a follow-on guide — but the regulatory point holds: protection is the residual layer after source, path, and administrative controls, not a first-line response.

How to apply the hierarchy in practice

In the order that survives an HSE inspection:

Step 1: Take the assessment outputs as your starting point. For each exposure above an action value, list the source contributing most to the daily exposure (the LEP,d driver). The control hierarchy is applied per-source, not per-worker. For step-by-step guidance on producing those assessment outputs, see How to Complete a Noise Risk Assessment.

Step 2: Walk down the hierarchy for each source. For each contributing source ask, in order:

• Can we eliminate it? (Document the answer.)
• Can we substitute it for something quieter? (Document.)
• What engineering controls are reasonably practicable? (Document costs, expected reductions, decisions.)
• What administrative controls fit alongside engineering controls? (Document the rota or scheduling change.)
• What hearing protection fills the residual gap? (Document SNR requirement and issue process.)

Step 3: Cost and prioritise. A control that costs £200 and reduces a top-three contributing source by 6 dB(A) is almost always reasonably practicable. A control that costs £20,000 to chase the last 1 dB(A) usually is not. Document the reasoning either way — "not reasonably practicable because [specific reason]" is a valid outcome, but only if it is written down and supportable.

Step 4: Implement in waves, not all at once. Most SME workshops cannot retrofit five controls simultaneously. Pick the highest-value action this quarter, the next two for the following quarter, and so on. The compliance trail is the action plan with target dates and the dated record showing each item was completed (or formally deferred with reasoning).

Step 5: Reassess after major controls land. Once a significant engineering control is in place, the noise environment has changed. Reassess to confirm the expected reduction was achieved — the assessment is a calibration check, not just a one-off compliance step.

Documenting controls — what HSE inspectors look for

A noise control programme without documentation is, in practice, no programme at all. The information that holds up under inspection:

• Source list linking each high-exposure source to the control measure assigned to it
• Decision log showing which controls were considered, which were applied, and the reasoning for any rejected
• Implementation evidence — purchase orders for new equipment, photos before/after, dated maintenance records, contractor invoices for enclosure fitting
• Reassessment record showing the noise environment was re-measured (or re-estimated with reasoned argument) after major controls landed
• Reasonably-practicable reasoning for any controls deliberately ruled out — costs, disruption, alternatives considered

The pattern HSE inspectors flag most often is "we issued ear defenders" with no upstream control consideration. Even an honest "we looked at enclosure but the production layout makes it impossible without rebuilding the workshop, so we have prioritised hearing protection plus job rotation" is a defensible position — silence is not.

Common mistakes when applying the hierarchy

• Jumping straight to PPE — the most common compliance gap. Hearing protection is a layer in the hierarchy, not a substitute for it.
• One-size-fits-all controls — different sources need different controls. A list of "we use enclosures" without saying which enclosures on which sources is not a programme.
• No record of rejected controls — if a higher-tier control was considered and ruled out, the reasoning needs to be on file. Without it, an inspector will read the absence as "you never considered it."
• Stopping after the first wave — controls reduce exposure incrementally. A workshop that lands one engineering control and then stops has not met the "as low as reasonably practicable" duty if other sources still drive exposure above action values.
• Forgetting administrative controls — rotation, scheduling, and quiet zones are real controls and count toward "reasonably practicable" reasoning. Treating them as separate from "real" engineering controls misses easy wins.

Frequently asked questions

What are the three main methods of noise control?

The three categories most often cited in HSE guidance and training are: (1) controls at the source (elimination, substitution, engineering controls applied to the equipment), (2) controls in the path (enclosures, screens, acoustic absorption), and (3) controls at the receiver (administrative controls and hearing protection). The five-tier hierarchy in the regulations expands these into elimination → substitution → engineering → administrative → personal protection.

What is the hierarchy of noise control?

It is the ordered priority for choosing controls: eliminate the noise source if possible, substitute it with a quieter alternative if not, apply engineering controls at source or in the path, apply administrative controls to limit exposure time, and use hearing protection as the residual layer. Regulation 6 of the Control of Noise at Work Regulations 2005 requires you to demonstrate you have considered the hierarchy before relying on PPE.

What are examples of administrative controls for noise?

Job rotation between high-noise and low-noise tasks, scheduling noisy work outside peak occupancy, designating quiet break areas, restricting access to high-noise areas to operators only, and adjusting maintenance schedules so noisy machinery does not run when it is not needed. Administrative controls reduce the time individual workers spend exposed rather than reducing the noise level itself.

Connecting controls to the assessment record

The hierarchy is not a parallel exercise — it is the implementation arm of the assessment. The exposure figures tell you what the action plan must address; the hierarchy tells you in what order to address it. The action plan tracks who does what by when; the implementation record proves it happened. For the assessment side of the workflow, see Noise Risk Assessment Control Measures for what the action plan should contain. For the regulatory framework that underpins the duties, see UK Noise at Work Regulations: The Complete Employer Guide.

Sources

• The Control of Noise at Work Regulations 2005 — legislation.gov.uk
• Regulation 6 (Elimination or control of exposure to noise at the workplace) — legislation.gov.uk
• L108: Controlling Noise at Work (3rd edition, 2021) — HSE
• How do I reduce noise? — HSE
• Managing noise risks: checklist — HSE
• The Supply of Machinery (Safety) Regulations 2008 — legislation.gov.uk