Noise may damage your hearing and cause other health effects such as:
- hypersensitivity to noise
- increased blood pressure
- increased heart rate.
Noise can also interfere with your performance, communication and slow your reaction times, which could lead to accidents.
PCBUs, employers and workers should refer to the Managing noise and preventing hearing loss at work - Code of Practice further information.
Hearing damage and loss can either occur swiftly or over an extensive period of time.
Very loud sounds can damage the inner ear, resulting in deafness. This may be temporary or permanent, depending on the noise level and length of exposure.
Permanent hearing loss can occur when high noise exposure is repeated over many years, or if someone is exposed to very intense or explosive sounds (eg a gunshot or explosion). In some cases a very intense sound can actually perforate the eardrum.
The harmful effects of noise may be cumulative and not necessarily confined to the workplace. The use of personal music players, stereo units, loud concerts and frequent nightclubbing may cause hearing damage to both young and older people.
Dangerous noise levels
As people respond differently to noise, the exact level at which noise will cause damage is not certain for each person. However, the amount of damage caused by noise depends on the total amount of energy received over time and each person's susceptibility to hearing loss.
Most people are protected from long-term damage in a working day (8 hours) by keeping exposure around the 85 decibel (dB)(A) level. But if noise exposure becomes more intense, damage may occur in a shorter time. This is not to imply that a safe condition exists at below 85 dB(A). It simply means that an eight-hour exposure of 85 dB(A) is considered to represent an acceptable level of risk to hearing health in the workplace.
Impulse or sudden noise levels in excess of the peak exposure standard of 140 dB(C) are considered to be hazardous and capable of causing immediate hearing damage.
Identifying noise hazards
While a noise assessment should only be conducted by a competent person, PCBUs and employers can make a preliminary assessment to identify sources of hazardous noise. Any assessment should be done in consultation with those who understand the work processes, such as affected workers and their Health and Safety Representatives.
To minimise the risks effectively, firstly conduct a walk-through inspection of your workplace to help determine:
- sources of excessive, distracting or disruptive noise which make it difficult to hear a normal voice within one metre of a noise source
- workers likely to be exposed to excessive noise
- work activities that are noisy and may pose a risk to hearing
- ways of reducing noise levels.
Make sure you also follow the manufacturer's instructions on noise levels when operating specific items of plant and machinery.
Controlling risks of noise exposure
Taking action to eliminate the noise source is important. If you are unsure about the level of exposure or how to minimise the risk effectively, you should:
- keep noise levels below the exposure standard of 85 decibels (dB)(A) in an 8-hour day so that critical situations can still be communicated despite the noise
- substitute noisy machinery with quieter models, or ‘buy quiet’ when purchasing new or replacement equipment, which is a cost-effective way to control noise at the source
- introduce engineering controls to treat noise at its source or in its transmission path, such as using sound dampeners or silencers, noise barriers/partitions/screens and isolation
- introduce administrative controls, such as training and education, job rotation, job redesign or designing rosters, to reduce the number of workers exposed to noise
- provide personal protective equipment (PPE) that is:
- suitable for the nature of the work and the hazard, such as earmuffs and earplugs
- comfortable to wear, and of a suitable size and fit
- maintained, repaired or replaced when required
- used or worn by workers who have been trained in its use and care.
If workers are frequently required to wear PPE to reduce the risk of hearing loss, implement an audiometric testing regime and keep testing records.
There is evidence that workers who are exposed to vibration and noise at the same time are more likely to suffer hearing loss than workers exposed to the same level of noise alone. Exposure to both vibration and noise is also understood to increase musculoskeletal problems.
Safe Work Australia has developed a series of guidance material on:
- managing the risks associated with vibrating plant in the workplace, and
- the measurement and assessment of workplace vibration exposures from vibrating plant.
Technical information is also provided on how exposures are to be measured and calculated.
You should use these guides if you are a worker or if you manage a worker who is exposed to or is likely to be exposed to vibration.
The guides for measuring and assessing vibration are targeted at people who, through training, qualification or experience, have acquired the knowledge and skills to carry out the task, for example occupational hygienists, ergonomists and other work health and safety professionals.