You must put noise control measures in place according to the hierarchy of control, so far as reasonably practicable.
The information below outlines how to reduce the effects of noise in the workplace.
New plant and workplaces
Noise control measures can be included in the design of the installation area and the design and construction of a new workplace. Where a plant is designed for a particular workplace, designers should design the plant to eliminate or control noise emissions where there is a risk to a person's hearing.
AS/NZS 2107 Acoustics: Recommended design sound levels and reverberation times for building interiors gives information on acceptable design sound levels for various building interiors.
Engineering controls for existing plant and workplaces
The need for noise control should be considered when deciding production methods or processes and when the need to reduce noise exposure has been established.
Examples of engineering controls can include:
- reducing noisy machine operations by replacing rivets with welds
- redesigning machinery power sources to give quiet speed regulation, for example through the use of stepless electric motors
- avoiding metal-to-metal contact by using plastic bumpers
- repairing loose and rotating parts, replacing worn bearings and gears and regular maintenance
- adding noise barriers, noise enclosures, vibration isolation mountings, laggings, mufflers and silencers where appropriate to reduce noise at source
- absorbing acoustic shock by providing wear-resistant rubber or plastic coatings
- using conveyor belts rather than rollers
- stiffening and fixing damping materials to panels and other surfaces to reduce vibration and noise impact of items during processing
- using a sound-reducing enclosure that fully encloses the machine(s)
- separating the noisy area and area to be quietened by a sound-reducing partition
- using sound-absorbing material on floors, ceiling and/or walls to reduce the sound level due to reverberation
- using sound-absorbing baffles between workers and the noise source
- using acoustical silencers in intake and exhaust systems, for example, internal combustion exhaust systems or air conditioning systems.
Administrative controls should be used when it is not possible to reduce noise exposure through engineering noise control measures. These include:
- organising schedules so that noisy work is done during a particular part of the shift or when as few people as possible are present
- notifying people in advance when noisy work is to be carried out so they can limit their exposure to it
- keeping people out of noisy areas if their job does not require them to be there
- sign-posting noisy areas and providing quiet areas for food and rest breaks
- limiting the time workers spend in noisy areas by moving them to quiet work areas before their daily noise exposure levels are exceeded
- maintaining machines and equipment in good condition to reduce noise, including the addition of noise mufflers, vibration isolators, or duct silencers
- job rotation (changing tasks carried out by workers to prevent exposure to excessive noise)
- purchasing new plant and equipment that produce less noise.
Personal hearing protectors
A personal hearing protector can be worn to cover the ear and ear canal entrance, or inserted in the ears of a person to protect their hearing. Personal hearing protectors should be used when noise levels cannot be reduced by other control measures.
Staff at workplaces should be:
- supplied with personal hearing protectors of correct rating and suitable for the work conditions
- instructed in their correct use
- instructed to wear them when exposed to noise
- monitored to ensure they wear hearing protection.
Personal hearing protectors should not be used as a substitute for engineering or administrative noise control measures.
Areas where people may be exposed to excessive noise should be signposted as 'hearing protection areas' at every entry point to the areas. The boundaries of these areas should be clearly defined.
No person, including visitors, managers or supervisors, should enter a hearing protection area during normal operation unless they wear appropriate personal hearing protectors, however short the entry period.
Signs used to identify these areas should conform to AS1319: Safety signs for the occupational environment. Correct selection can be confirmed with a supplier of workplace health and safety signs. Additional signs within the hearing protection areas may also be necessary.
Detailed information for noise control management in new and existing workplaces may be obtained from Part 2: Noise control management of AS/NZS 1269 Occupational noise management.