What to look for in a good noise assessment

I feel for employers here as they know they need to get a noise assessment done so start looking into it, and quickly end up in a dark and murky world of Lep,d and TWA and dB(A) and dB(C) and lower limits and upper limits and are then told that a peak dB(A) is not that vital but it may be after all depending on how often it happens. It is a wonder they don’t end up sitting in a corner and weeping gently.

This is a guide on what to look for in a good noise assessment if you are getting a noise consultant in to do the survey for you. Sure, I would like it to be me, clearly, but this applies to anyone you are getting in to measure occupational noise risks for. you.

Noise assessment measure risks to people

I know that sounds stupid, but bear with me. A good noise assessment is not a list of noise levels for area of a workplace - commonly given as a map of the factory with noise levels marked on it. There can be a value in that, but it is not what the noise regulations want assessing.

Occupational noise assessment guide.

Extract from the Noise Assessment: Guide to Getting What You Need document produced by the HSE’s Engineering Industry Noise Task Group.

Noise assessments are not simply spot readings from around the workplace.

The Noise Regs are focused on what the noise risk is that people are exposed to which is a function of a few things:

• What the noise levels actually are for a job or machine

• How long they are exposed

• How often they are exposed

• And the combination of noises to which they are exposed

There are some exceptions

Now, just to confuse things, there are some cases where there is no option but to base a noise assessment on machine-specific noise levels but they are very limited and apply to workplaces where there is no set routine and jobs change considerably from day to day. For example, in a joinery workshop people may construct an item from start to finish rather than a production line, with the combination of machines used changing every day depending on what is needed. In those cases a daily average for any one day will have no relevance to a day’s exposure on any other day so there is no choice but to base it purely on the noise emitted by machines, but these types of place are the exception rather than the rule.

A good noise assessment should clearly tell an employer what is needed

Noise assessment reports can often go off on one into a lot of detail and a massive list of noise levels and that is all well and good, but what does it actually mean for the employer? A good noise assessment will include the supporting data, presented in a meaningful way hopefully, but should also:

• Tell the employer in clear language who is at risk and to what extent, using daily average noise exposure levels.

• Say whether hearing protection is adequate and suitable, or not.

• Give some recommendations for minimising noise levels where possible.

• Clearly identify which employees need the mandatory noise safety training and health surveillance.

The employer is not a noise-nerd and have plenty of other things to manage as well so a good noise assessment should make it clear what the employer needs to do next without burying it in jargon and a mass of numbers.

A good noise assessment should also explain why the recommendations are being made, and preferably without simply regurgitating the Noise Regs word for word - employers are asking for help in this meaning an element of interpreting the Noise Regs for their specific site, not to just get back pages and pages of what is already online.

Avoid the jargon

Noise dives into things like Lep,d, LA,eq, LC,eq and so on. This is meaningless to an employer so a good noise assessment should not hide behind it and should say what that actually means. To an employer what makes more sense, someone’s ‘Lep,d’ or someone’s ‘daily noise exposure’?

Are photographs important in a noise assessment report?

Important, no. Useful sometimes? Yes. Sometimes one photo can save an entire paragraph of text so they can be useful, but a lot of employers aren’t overly keen on photos being taken in the workplace and if that is the case then it is no problem and is not detrimental to the noise assessment report. Sometimes they are added more to bulk it out than to add much! If they don’t help then they aren’t necessary, and if no cameras are allowed then so be it and it is not a major issue.

Noise assessments must be done by someone competent

If you are getting a noise assessment done then competence is important. Competence is a function of three things:

• Qualification

• Experience

• Ability to actually write something clearly and that makes sense

There is no point in being qualified up to the eyeballs if there is no experience to back it up, and there is no point in having both experience and qualification if the noise assessor produces a report which tries to baffle with sheer size and technicality. A proven track record in all three is important.

There is no harm in asking a potential noise assessment consultant for a couple of previous clients you can give a quick shout to and ask if they were happy with it. A good noise assessor will have no issues with that, and they should be able to provide a sample noise assessment report as well.

Bear in mind, a generalist like a NEBOSH Diploma or a degree in Health and Safety or Occupational Hygiene is no guarantee of competence. I have a NEBOSH Diploma and on the basis of that alone I would not have considered myself competent to do noise assessments for clients, hence I also have Institute of Acoustics certification specifically in noise assessment. I have met a lot of people with degrees who couldn’t put their trousers on the right way round without help…

What type of noise meter will be used in the noise assessment?

The answer should be ‘whatever is most appropriate’. Sometimes it is wearables, sometimes it is static, sometimes it is hand-held and it all depends on what gets the right result for an individual workplace.