If you need to measure sound levels, protect employees, or maintain compliance with regulations, then you need workplace noise monitoring.
Workplace noise monitoring is the process of measuring the sound levels employees are exposed to during their normal work, so that exposure can be compared against the legal action and limit values and any necessary controls put in place. It often forms part of the process of assessing and managing workplace noise risk, whatever the source; machinery, tools, ventilation systems, vehicles or other equipment within the working environment.
Noise exposure isn’t just a nuisance, it’s a significant occupational health risk. Prolonged or repeated exposure to high noise levels can lead to permanent hearing damage, even if the exposure seems tolerable day-to-day. It can also contribute to fatigue, stress, and reduced concentration, increasing the risk of workplace errors. From a business perspective, excessive noise can affect productivity, increase absenteeism and invite regulatory scrutiny.
Beyond hearing loss, excessive noise can mask alarms, warnings and verbal instructions, increasing the risk of accidents in environments like manufacturing and pharmaceutical production where clear communication matters. Monitoring provides the evidence employers need to identify where these risks are highest and act early.
The parameters measured depend on the noise present. Workplace noise commonly falls into several categories, each posing slightly different risks. For a broader look at what counts as workplace noise and why it matters, see our guide to workplace noise.
Continuous noise is steady and persists over time; the hum of machinery, generators or ventilation systems running throughout a shift. Although often perceived as background noise, continuous exposure can cause gradual hearing fatigue and permanent damage if levels exceed safe limits.
Intermittent noise fluctuates in intensity or frequency at irregular intervals, such as equipment cycling on and off or tools in a busy workshop. Repeated exposure can still exceed safe daily limits even if each event seems temporary, and monitoring helps identify peak exposures that might otherwise go unnoticed.
Impulse noise is a sudden, sharp burst of sound; a hammer strike, explosion or metal impact. Even a single high-level impulse can cause immediate hearing damage, so these noise types are treated separately from continuous exposure when assessing risk.
Workplace noise can be measured in two main ways. Attended sound level measurements use a calibrated sound level meter at fixed or selected locations to characterise noise sources and general levels across an area. Personal dosimetry instead uses a small device worn by the employee, typically on the shoulder close to the ear, to record the sound level actually reaching them across a full shift.
Personal dosimetry is particularly useful for employees who move between different work areas, carry out a mix of tasks during a shift, or experience noise exposure that varies significantly through the day; situations a small number of fixed-position measurements cannot adequately capture. Sound level meter measurements remain valuable for mapping where the noise is coming from and identifying which sources are driving exposure. In practice, the two methods are often used together: dosimetry establishes what an individual is exposed to, and sound level measurements show where that exposure originates.
Employee noise exposure is normally expressed as LEX,8h, the daily personal noise exposure level normalised to a standard eight-hour working day. This allows exposure from different tasks, machines and time periods to be combined into a single, comparable figure. Alongside LEX,8h, peak sound pressure level (LpC,peak) captures brief, high-intensity events, an impact tool or a sudden mechanical bang for example, that can cause immediate damage even where the average exposure across the day is unremarkable.
In Ireland, workplace noise is governed by the Safety, Health and Welfare at Work (General Application) Regulations 2007 (Part 5, Chapter 1: Control of Noise at Work), which set specific exposure values to protect workers from hearing damage. The lower exposure action value is 80 dB(A) LEX,8h, and the upper exposure action value is 85 dB(A) LEX,8h. Above the 87 dB(A) exposure limit value, assessed behind any hearing protection, employers must not allow exposure to continue without effective controls. For a full explanation of what each threshold requires, see our guide to workplace noise regulations in Ireland.
Workplace noise monitoring is typically required where a risk assessment indicates that employees may be exposed at or above the lower exposure action value, or where measurements are needed to establish the extent of exposure. As a practical indicator, if people have to raise their voices to be clearly heard about two metres apart, the noise level is likely to warrant further assessment.
Where exposure exceeds the lower exposure action value, preventive audiometric testing must be made available. Where exposure exceeds the upper exposure action value, employees must be offered a hearing check carried out under the responsibility of a registered medical practitioner.
There is no single fixed interval that applies to every workplace. Monitoring should be appropriate to the exposure conditions present, and repeated whenever those conditions may have changed; for example where work processes or equipment change, where layouts or shift patterns are altered, or where previous results may no longer be representative of current conditions. Where exposure is more variable, longer-term or continuous monitoring can be a useful option, but it is not a universal requirement triggered automatically by a single reading. The risk assessment itself should indicate when reassessment is necessary.
Noise control measures are typically the outcome of workplace noise monitoring. Once areas of concern have been identified, the results translate into action: reducing exposure at source, protecting workers and maintaining compliance.
Effective noise control combines accurate measurement with practical engineering. High-risk areas are identified and tailored solutions developed for each specific noise source, airborne, structural or process-related, which may include acoustic enclosures, silencers, vibration isolation or sound-absorbing materials. Where a significant source needs engineering intervention, this work is typically carried through into industrial noise control design.
When noise cannot be adequately controlled by other means, hearing protection forms part of the control strategy. Above the lower exposure action value, suitable hearing protection must be made available; at or above the upper exposure action value, it must be used. Correct selection, fit and training are important, but hearing protection should not replace practical measures to reduce noise at source.
Workplace noise monitoring is the measurement component: it establishes what employees are actually exposed to. A workplace noise risk assessment goes further, considering those measurement results together with employee tasks, exposure duration, operating conditions, the applicable action and limit values, existing controls and hearing protection, to determine what risk-control measures are required.
Occupational noise exposure may be assessed using measurement strategies consistent with ISO 9612, together with the applicable Irish workplace noise requirements. Personal dosimetry, attended sound level measurements and noise mapping are typically combined to build a clear picture of who is exposed, where the risk is coming from and which controls will make the greatest difference.
Workplace noise monitoring often forms part of a wider workplace noise and vibration risk assessment, which can also include personal dosimetry, noise mapping and vibration exposure where relevant.
Need a workplace noise or vibration risk assessment? Allegro Acoustics provides workplace and occupational noise surveys, personal dosimetry, noise mapping and hand-arm and whole-body vibration assessments, together with practical guidance on controls and compliance.
Your enquiry is on its way. We'll be in touch shortly.
