Noise Management FAQs

The easiest way to establish whether your hearing protection is sufficient is to look at the ‘single number rating’ (SNR). This information will be available on the hearing protection box. This method is suitable for general industrial and occupational noise sources. If the noise is dominated by single frequencies or the noise is very loud ‘peak’ noise, such as a gunshot, a different assessment method must be used.

The single number rating is the amount that the noise levels at the ear will be reduced by. You need to know the C-weighted noise level for this calculation. Earplugs with an SNR of 25 will bring noise levels of 100dB down to 75dB at the ear. However, the HSE advises that you also take into account “real world factors” by adding on 4dB to your final number. This will allow for factors such as poor fit to be taken into account and give you a more realistic estimation of the suitability of your hearing protection.

Noise levels at the ear must be brought down to below 85dB. Ideally, you should aim for between 75-80dB. All hearing protection should carry the CE mark which means it will satisfy the relevant part of BS EN 352 (Hearing Protectors. Safety Requirements and Testing). 

Related service: Noise Risk Assessment

You are required to have a risk assessment by law if the daily ‘personal noise exposure’ of any of your employees, or people carrying out work on your behalf, is 80dB (A-weighted) or above. ‘Personal noise exposure’ is a specific calculation that is required by the regulations, and it takes into account the actual noise levels as well as the amount of time your workers are exposed to the noise each day or each week.

If your work is in an industry that is typically noisy, such as construction, engineering, transport, general manufacture, food production or music and entertainment you will normally exceed the 80dB exposure value and you will, therefore, require a noise risk assessment. You will also usually require a noise risk assessment if your building contains a back-up power generator that is tested regularly, or if you are responsible for grounds maintenance using noisy equipment such as chainsaws and mowers.

The HSE advises that if the noise level that your workers are exposed to is similar to the sound of a crowded restaurant, busy street or vacuum cleaner then it is likely to be around 80dB. A normal conversation will be possible but the noise will be intrusive. If the conditions are like this for 6 to 8 hours a day you will need a noise risk assessment. For a noise that is any louder, or if you have to shout to hold a conversation with someone nearby, you will need a noise risk assessment even if people are exposed for only very short periods during the day.

In addition to the A-weighted noise level (which is the type of noise that applies to most industries), you will also require a risk assessment if the peak sound pressure your employees are exposed to is 135dB (C-weighted) or above. Peak exposures are common in some manufacturing industries, as well as people who work with firearms and fireworks.

If you are not sure whether you need a noise risk assessment, you should err on the side of caution, and carry one out.

Related service: Noise Risk Assessment

If you are the person, or employer, in overall control of a building or a project, then yes, you are responsible for making sure that the noise risks are assessed and that the information on noise is made available to all affected employers.

You have a responsibility to work with your contractor, or any other employer who is affected by the noise, to make sure that any identified noise control measures are carried out. This includes identifying areas where hearing protection must be worn, and ensuring appropriate signage and information is in place. You also have a responsibility to provide instruction and training to your contractors in relation to the specific work they are doing for you. However, health surveillance (hearing tests) need only be provided by the direct employer of the workers affected.

Similarly, if you have mobile workers that may be exposed to noise at premises outside of your control, you do still have a responsibility to assess the risks and put any necessary control measures in place.

Employers need to communicate with each other to ensure that they are all meeting their obligations to protect workers’ hearing. You should never assume that someone else has already assessed the risks.

Related services: Noise Risk Assessments

It is a legal requirement to review your risk assessment regularly, as well as to review it sooner if you suspect it may no longer be valid or if there has been a significant change in the work being carried out. As with all risk assessments, your noise risk assessment should be reviewed on at least a two-yearly basis, even if it appears nothing has changed in your workplace. 

If circumstances change in your workplace, such as new work processes, newly introduced noise control measures or new shift patterns, or if new machinery is purchased, you should review your noise risk assessment to ensure that your employees still have suitable protection. Your risk assessment should also be reviewed if you become aware of new noise-control techniques, or if control measures that were not originally practicable become more achievable (for example due to better technologies or reduced costs).

If you carry out health surveillance (hearing tests) on your employees and the results indicate that hearing damage is occurring, the risk assessment must be reviewed as you will need to improve your control measures.

Related service: Noise Risk Assessment

The ‘SNR’, or ‘single number rating’ is one of the ways in which the effectiveness of hearing protection is measured.

The single number rating is essentially how many decibels the noise level at the ear will be reduced by. It is calculated using the measured C-weighted noise level. For example, hearing protection with an SNR rating of 30 will reduce the noise levels by 30dB.

This does not take into account “real world factors” and as such the HSE recommend that 4dB is added on to ensure that employees are given adequate protection.

Related service: Noise Risk Assessment 

A ‘positive noise purchasing policy’ is a written policy which confirms that you will take noise levels into account when purchasing new plant or machinery. Noise levels are available for all new machinery and should be compared when you purchase new equipment.

Where it is deemed necessary to purchase machinery which increases the noise exposure to your employees the HSE advises that a record is kept of the reasoning behind this decision. 

Related service: Noise Risk Assessment