EXAMPLES OF WAYS TO REDUCE NOISE EXPOSURE LEVELS IN THE WORKPLACE

The Noise Regs say that hearing protection is a last resort and that the employer must exhaust all other means of reducing noise exposures first, before reaching for hearing protection.

These are some examples of noise control measures I have come across during noise assessments - not all of them are overly complex or cost a lot of money, but they were effective.

You don’t have to make a dramatic difference in the dB numbers to make a significant difference.

Remember the old chestnut that 3dB represents a doubling of the noise risk going up, or a halving of the noise risk going down. This means that if you have a noise level of 95 dB(A) and you do some work and get it to 92 dB(A), don’t be disappointed and think ‘that is only 3dB, it wasn’t worth the effort’. That 3dB change has halved the risk of hearing damage for your staff working there and is a significant improvement.

I have to flag that all the examples below are cases I have actually measured, in real production environments, but the number of decibels you may achieve could vary a little. For example, certain frequencies of sound are harder to stop than others so some noises may penetrate slightly better than others.

Some noise attenuation is good, even if they still venture into the noisy area sometimes

Don’t forget, the Noise Regs are focused on the average noise exposure for people, not just occasional bursts above 85 dB(A) and a cabin / refuge / machine enclosure / curtain / partition wall could mean people don’t need hearing protection at all, even if still occasionally exceeding a noise level of 85 dB(A) for short times as they monitor equipment.

As an example of what I mean:

  • ≈93 dB(A) is a typical industrial continual noise level.

  • If an operator can monitor the machine from inside a cabin or the machine is inside an enclosure, then we can expect the operator’s levels to be ≈73 dB(A).

  • That would mean they could go in the noisy area of 93 dB(A) area for up to an hour every day and their average noise exposure for the day would be 84 dB(A), still below the limit.

  • That would mean hearing protection is not needed and things like a need for hearing testing would also not apply.

Even if they went into the noisy area for more than the hour there is the benefit that they would then only need hearing protection for that time rather than wearing it all day.

This is also compliant with the HSE’s Noise Regs as well where they require average noise exposures to be reduced to as low as possible, even if still exceeding the upper limit.

It is a low cost and effective control if space and the working routine permits it.

The humble plastic strip curtain

Commonly used around industry, the plastic strip curtain can be very effective as a noise control measure. What I am talking about here is the simple translucent plastic hanging strip curtain which is often used to divide rooms in a factory.

I have measured many of these during noise assessments and typically they can give a reduction in the noise of anything from 10 to 14 dB, which given 3dB is a doubling of the noise energy, is quite a significant change.

On a noise assessment I measured levels of ≈73 dB(A) on one side of a curtain, and then it jumped immediately to ≈87 dB(A) on the other side. The curtain is very effectively containing the noise and means one area can stay below the limits and no hearing protection is needed.

Partitioning a site with these doesn’t hinder passage of goods or personnel through them, but they are an effective and simple noise control measure. And cheap and cheap is always nice.

This video is a walk-though showing the live noise levels on either side of this plastic curtain.

The impact of plastic curtains on noise levels in a noise assessment

Plasterboard walls as a noise control

Another entry in the ‘it doesn’t have to be over-engineered to make a difference’ is the standard plasterboard partition wall. By this I mean the normal build of a wooden frame (sometimes metal) with a 12mm plasterboard sheet on each side, insulation in the middle and then plastered. Basically the normal wall used in houses, etc.

On a noise assessment in 2025 I measured the noise in a production area where the production office was right among the noisy machinery.

  • Immediately outside the office noise levels were ≈80 dB(A).

  • Immediately inside the office with the door closed noise levels were ≈59 dB(A).

That plasterboard wall and office door were reducing noise levels by a good 20 dB(A).

Job rotation can also be very effective as a noise control

On a noise assessment in 2024 I came across a site which has an area of 86 dB(A), and another of 82 dB(A). At the time one person was based all the time in each, meaning one had a regular exposure of over the 85 dB(A) limit and one was under it.

As both jobs were similar I recommended that they use job rotation so each person did a maximum of 2 1/2 days on each. That gives them a weekly exposure of 84 dB(A), below the limit.

In a noise assessment, when assessing the typical noise exposures weekly limits are just as valid as the daily ones, so you can use this to manage a job rotation system, limiting the number of days someone spends on a higher noise job.

Acoustic enclosures - used to enclose a machine or to provide an operator cabin

The are purpose-built enclosures which can be small and around a single machine or large covering huge things like printing presses.

The enclosure doesn’t have to be around the machine though, it could be around the person creating an operator cabin for staff who can stay in one place for at least part of their working routine.

Printing press example

I was on a site which had large printing presses, enormous room-sized things, and they had acoustic enclosures around them, separating the machine from the personnel. Levels inside the enclosure were averaging 91 dB(A), while outside it levels were ≈80 dB(A), even with the door open. Where the operator stood levels were more ≈78 dB(A), so below even the lower limit.

Grinding room example

A client had a small grinding room and noise levels inside it were ≈95 dB(A). A purpose-built acoustic enclosure forming a room around it had been built and levels immediately outside were ≈78 dB(A). From over the upper limit to not reaching the lower limit - a great solution for the other staff located nearby but on much quieter machines.

Small press example

Acoustic enclosure around an individual press. Inside levels were 90 dB(A), while outside it they were ≈81 dB(A), even with the door open.