Noise Risk Assessment Control Measures: What to Do After the Survey

The noise assessment is done. You know which workers are exposed, what the levels are, and which action values are exceeded. Now what?

This is where most employers stall. The assessment report identifies the problems, but the practical work — choosing controls, implementing them, documenting what you did, and maintaining the evidence trail — is where compliance actually happens. Most guidance on noise risk assessments stops at "implement controls" without explaining how to decide which controls to implement first or how to document the follow-through.

This guide covers post-assessment control measures under UK regulations. It is not a substitute for professional advice where your noise environment is complex or exposure levels are borderline.

The control hierarchy — and why hearing protection is not the answer

The Control of Noise at Work Regulations 2005 (Regulation 6) require you to reduce exposure so far as is reasonably practicable. HSE expects you to work down a hierarchy, not jump to the bottom:

1. Eliminate — remove the noisy process entirely
2. Substitute — replace noisy equipment with quieter alternatives
3. Engineering controls — enclosures, barriers, damping, isolation mounts, silencers
4. Administrative controls — reduce time in noisy areas, rotate workers, adjust schedules
5. Hearing protection — ear defenders or plugs, used while other controls are being implemented or where they cannot reduce exposure enough

Issuing ear plugs and considering the job done is the most common compliance gap HSE finds during inspections. The regulations specifically require you to consider controls higher up the hierarchy first and to document why you chose the approach you did. For the full regulatory framework, see UK Noise at Work Regulations: The Complete Employer Guide.

Practical decisions for each control type

Elimination and substitution

These are the most effective controls and the hardest to implement. Most workplaces cannot simply stop using noisy equipment. But ask whether:

• A process can be redesigned to remove an impact operation (e.g., bolting instead of hammering)
• A quieter machine model exists that does the same job (many manufacturers now publish noise emission data in CE declarations)
• A different cutting method, tool, or material produces less noise

Substitution does not have to solve the entire problem. Replacing one machine that drops exposure from 92 to 88 dB(A) still reduces risk, even if further controls are needed.

Engineering controls

Where elimination is not practicable, engineering controls reduce noise at source or between source and worker:

Control type	How it works	Typical applications
Enclosures	Surround the noise source with sound-absorbing panels	CNC machines, compressors, pumps
Barriers and screens	Block the direct path between source and worker	Between machine bays and adjacent workstations
Damping	Reduce vibration of panels, guards, chutes, and hoppers	Sheet metal guards, conveyor systems
Isolation mounts	Decouple the machine from the floor to reduce structural noise transmission	Presses, impact machines, generators
Silencers	Reduce noise from air exhausts, ventilation, and pneumatic systems	Compressed air tools, extraction systems
Maintenance	Worn bearings, loose panels, and degraded seals increase noise. Routine maintenance is a noise control.	All machinery

The key question for engineering controls is cost-effectiveness. You do not need to enclose every machine. Start with the sources that contribute most to the highest-exposed workers. An enclosure on a circular saw that runs 3 hours per day does more for LEP,d than one on a band saw used for 30 minutes.

To estimate how reducing one source's noise level affects daily exposure, use the free Noise Exposure Calculator.

Administrative controls

These do not reduce the noise itself but reduce how long workers are exposed:

• Job rotation — share time in noisy areas across more workers so no individual exceeds action values
• Scheduling — run the noisiest operations when fewer workers are present
• Work area separation — move workstations further from noise sources where layout allows
• Break scheduling — ensure breaks are taken away from noisy areas

Administrative controls have limits. Rotating workers so that more people are exposed at lower levels is not the same as reducing the noise. And they depend on consistent implementation — a rotation schedule only works if someone enforces it.

Hearing protection

Hearing protection is the last resort, not the first response. When it is needed:

• Select the right type — the attenuation rating (SNR) must reduce effective exposure below the exposure limit value (87 dB(A)) and ideally below the upper action values (85 dB(A)). Over-protection (reducing sound too much) is also a problem — workers who cannot hear warnings or speech will remove their protection.
• Issue and record — log who received what protection, when, and the product's SNR. This record matters for both compliance and claims defence.
• Enforce in hearing protection zones — areas where exposure reaches or exceeds 85 dB(A) must be signed and hearing protection must be worn by everyone entering. Use the free Hearing Protection Zone Checklist to check your zones.
• Maintain and replace — disposable plugs degrade. Reusable defenders need cleaning and cushion replacement. Budget for ongoing supply.

Documenting control measures

The assessment identified gaps and created an action plan. Now you need evidence that the actions were completed. For each control measure:

1. Record what was implemented — the specific control, when, and by whom
2. Record the outcome — did it reduce exposure? By how much? (Re-estimate or re-measure after implementation)
3. Record ongoing maintenance — engineering controls degrade. Log inspections and maintenance actions
4. Record PPE issue — name, date, product, and attenuation rating for each worker
5. Link back to the assessment — each control should trace to a specific gap or action item in the noise risk assessment

This evidence trail is what separates a compliant employer from one who has a filed assessment report and nothing else. For a worked example of an assessment with an action plan, see Noise Risk Assessment Example.

Prioritising control measures

You rarely implement everything at once. Prioritise by:

1. Workers above the exposure limit value (87 dB(A)) — immediate action required. This is a legal ceiling that must not be exceeded.
2. Workers above upper action values (85 dB(A)) with no hearing protection — highest-risk compliance gap
3. Workers above upper action values with hearing protection but no other controls — you need to demonstrate you considered the hierarchy
4. Engineering controls that reduce exposure for multiple workers — highest cost-effectiveness
5. Health surveillance gaps — workers who should have audiometry but do not

For a detailed breakdown of what each threshold requires, see UK Workplace Noise Exposure Limits.

The review cycle

Control measures are not a one-off implementation. The regulations require you to review when circumstances change, and HSE guidance advises regular review at least every one to two years.

Triggers for earlier review:

• New equipment, processes, or layouts
• Health surveillance results showing hearing deterioration
• Changes in the number of exposed workers or their exposure patterns
• Control measures not being used or maintained as intended
• Worker complaints about noise

Each review should check: are the controls still in place, still working, and still sufficient? If not, update the assessment and the action plan.

For step-by-step guidance on the assessment process itself, see How to Complete a Noise Risk Assessment. For more on HSE's specific guidance documents, see HSE Noise Assessment Guidance.

Sources

• The Control of Noise at Work Regulations 2005 — legislation.gov.uk
• How do I assess the risks? — HSE
• Noise at work: regulations — HSE
• L108: Controlling Noise at Work (3rd edition, 2021) — HSE